ISO 21396

• Abstract:

  ISO/TS 21396:2017 specifies a method for the determination of the soil or sediment mass concentration (μg/g) of tyre and road wear particles (TRWP) in environmental samples. ISO/TS 21396:2017 establishes principles for soil or sediment sample collection, the generation of pyrolysis fragments from the sample, and the quantification of the generated polymer fragments. The quantified polymer mass is used to calculate the concentration of TRWP in soil or sediment. These quantities are expressed on a TRWP basis, which includes the mass of tyre tread and mass of road wear encrustations, and can also be expressed on a tyre rubber polymer or tyre tread basis. NOTE Tyre and road wear particles are a discrete mass of elongated particles generated at the frictional interface between the tyre and roadway surface during the service life of a tyre. The particles consist of tyre tread enriched with mineral encrustations from the roadway surface.

• Status: Not Published
• ICS: 13.080.01 - Soil quality and pedology in general
• ICS: 83.060 - Rubber
• ICS: 83.160.01 - Tyres in general
• Technical Committee: ISO/TC 45 - Rubber and rubber products
• Drafting Committee: ISO/TC 45/WG 16 - Environmental aspects and sustainability
• Current Stage: 6000 - International Standard under publication
• Start Date: 18-Aug-2026
• Completion Date: 19-Sep-2026

• Revises: ISO/TS 21396:2017 - Rubber — Determination of mass concentration of tire and road wear particles (TRWP) in soil and sediments — Pyrolysis-GC/MS method
• Effective Date: 06-Jan-2024

Overview

ISO 21396 is an international standard developed by ISO Technical Committee 45 for the rubber and rubber products sector. This standard outlines a method for the quantitative determination of the mass concentration of tyre and road wear particles (TRWP) in soil and sediment samples using pyrolysis-gas chromatography/mass spectrometry (GC/MS). The method enables environmental laboratories to accurately assess the extent of TRWP contamination, which is a growing environmental concern due to the widespread use of rubber tyres and the resulting formation of microplastics and particulate pollution.

Tyre and road wear particles are created at the interface between vehicle tyres and the road surface during normal use. These elongated particles are composed of tyre tread material, often with mineral components from the roadway. Accumulation of TRWP in soil and sediment can have ecological and health impacts, making effective measurement vital for monitoring and mitigation strategies.

Key Topics

• Scope and Purpose
  ISO 21396 focuses specifically on the analysis of soil and sediment for TRWP content, expressed in micrograms per gram (μg/g). It does not cover analysis of ambient air or water samples.

• Analytical Method
  The standard employs pyrolysis-GC/MS, where organic polymeric molecules are thermally decomposed to characteristic fragments. These fragments are then separated via gas chromatography and quantified by mass spectrometry.

• Sample Collection and Preparation

  • Outlines the proper techniques and equipment for collecting representative soil or sediment samples.
  • Details requirements for drying, sieving, and homogenizing samples to minimize contamination and ensure consistent analysis.

• Calibration and Internal Standards

  • Utilizes deuterated internal standards to improve precision and correct for matrix effects during analysis.
  • Requires preparation of calibration curves using known quantities of synthetic rubber polymers.

• Quality Control

  • Establishes the use of laboratory blanks and performance verification to ensure absence of polymer contamination.
  • Specifies acceptable levels of drift in calibration data.

• Reporting and Calculation

  • Provides formulas and procedures for calculating TRWP mass concentrations, accounting for sample preparation and mass loss during pre-treatment.

Applications

The procedure specified in ISO 21396 has significant practical value for various stakeholders:

• Environmental Laboratories and Researchers
  Enables accurate monitoring of microplastic pollution from tyre wear in soil and sediment, supporting long-term environmental studies.

• Regulatory Agencies and Policy Makers
  Supplies reliable, standardized data for risk evaluations and the development of policies targeting non-exhaust particulate emissions.

• Roadway and Urban Planners
  Assists in assessing and managing the impact of road wear on local soil and sediment quality.

• Rubber and Tyre Manufacturers
  Facilitates lifecycle assessment and corporate environmental responsibility reporting by quantifying downstream effects of tyre use.

• Sustainability Initiatives
  Supports monitoring efforts required for sustainability certifications and impact reduction programs related to vehicle usage and maintenance.

Related Standards

For laboratories and organizations implementing ISO 21396, the following related standards may also be relevant:

• ISO 17257
  Rubber - Identification of polymers - Pyrolytic gas-chromatographic method using mass-spectrometric detection
  Provides guidance on the general use of pyrolysis-GC/MS for polymer identification and complements the analytical techniques used in ISO 21396.

• ISO 3310-1
  Test sieves - Technical requirements and testing - Part 1: Test sieves of metal wire cloth
  Standardizes sieving procedures, which are critical for sample preparation.

Practical Value

By providing a robust, repeatable, and internationally harmonized method for measuring tyre and road wear particles in soil and sediment, ISO 21396 supports the growing need for microplastic pollution assessment. The standard's protocols increase confidence in data quality, aid in environmental risk management, and form the basis for informed decisions by industry, government, and research communities concerned with the environmental impact of vehicle-derived particulates. Using this standard ensures consistency and comparability of results across different laboratories and regions, enhancing the effectiveness of global environmental monitoring programs.

FINAL DRAFT
International
Standard
ISO/FDIS 21396
ISO/TC 45
Rubber — Determination of the
Secretariat: DSM
mass concentration of tyre and
Voting begins on:
road wear particles (TRWP) in
2026-06-22
soil and sediment — Pyrolysis-
Voting terminates on:
gas chromatography/mass
2026-08-17
spectrometry (GC/MS) method
Caoutchouc — Détermination de la concentration massique en
particules d'usure des pneumatiques et de la route (TWRP) dans
le sol et les sédiments — Méthode par pyrolyse-GC/MS
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 21396:2026(en) © ISO 2026

FINAL DRAFT
ISO/FDIS 21396:2026(en)
International
Standard
ISO/FDIS 21396
ISO/TC 45
Rubber — Determination of the
Secretariat: DSM
mass concentration of tyre and
Voting begins on:
road wear particles (TRWP) in
soil and sediment — Pyrolysis-
Voting terminates on:
gas chromatography/mass
spectrometry (GC/MS) method
Caoutchouc — Détermination de la concentration massique en
particules d'usure des pneumatiques et de la route (TWRP) dans
le sol et les sédiments — Méthode par pyrolyse-GC/MS
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 21396:2026(en) © ISO 2026

ii
ISO/FDIS 21396:2026(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents and materials . 3
6 Apparatus . 3
6.1 Soil or sediment sampling — Equipment and consumable supplies .3
6.1.1 Sampling device .3
6.1.2 Sample containers. . .4
6.2 Equipment for analysis . .4
7 Specimen preparation laboratory . . 5
8 Measuring range . 5
9 Limit of detection . 6
10 Procedure . 6
10.1 General .6
10.2 Sample collection . . .6
10.3 Deuterated internal standard preparation .6
10.4 Calibration curve preparation .7
10.4.1 Stock solutions.7
10.4.2 Calibration curves .7
10.5 Sample preparation .8
10.5.1 General .8
10.5.2 Oven drying .8
10.5.3 Sieving and homogenization .9
10.5.4 Sample pre-treatment .9
10.6 Sample measurement .9
10.6.1 Sample mass .9
10.6.2 Internal standard addition .9
10.6.3 Pyrolysis-GC/MS measurement .9
11 Analysis . 10
11.1 General .10
11.2 Tyre and road wear particles/limit of detection (TRWP LOD) .11
11.3 Quantity of tyre polymer in the sample .11
11.4 Mass concentration of TRWP .11
12 Performance characteristics .11
12.1 General .11
12.2 Specific performance characteristics .11
13 Test report .12
Annex A (informative) Recipe for calibration curves and stock solutions .13
Annex B (informative) Instrument conditions .15
Annex C (informative) Representative calibration curves and total ion pyrograms . 17
Annex D (informative) Calculation of tyre and road wear particle (TRWP) detection limits .22
Annex E (normative) Calculation of results using dimer markers .24
Annex F (informative) Precision .29

iii
ISO/FDIS 21396:2026(en)
Bibliography .30

iv
ISO/FDIS 21396:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products.
This first edition cancels and replaces (ISO/TS 21396:2017), which has been technically revised.
The main changes are as follows:
— addition of information regarding instrument conditions for the microfurnace pyrolyser and resistive
pyrolyser to 6.2.5.1;
— addition of recommendations for sample chemical pre-treatment to 10.5.4;
— revision of the calculation method to account for differences in elastomer microstructure between
calibration standards and marketplace average tread;
— addition of 4-phenylcyclohexene marker to 4., 8., 10.1, 10.3, 10.4.2, 10.6.3.4, 11.1, 11.4, Annex C, Annex D
and Annex E.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
ISO/FDIS 21396:2026(en)
Introduction
Tyre and road wear particles (TRWP) are formed as a result of tread abrasion from the road surface,
and subsequent particle release to the environment. TRWP consist of tyre tread particles which include
incorporated material from the road surface (see Reference [1]). The elastomeric fraction in TRWP contained
in soil or sediment materials is quantified in this document by direct pyrolysis-GC/MS (gas chromatography/
mass spectrometry) analysis. Mass concentration can be expressed on the basis of the rubber polymer,
tyre tread, or TRWP. This method has been used to measure the TRWP concentration in soil and sediment
samples (see References [2], [3], and [4]). The airborne concentration of TRWP in the PM and PM fraction
2.5 10
has also been characterized by a similar method (see References [5], [6], and [14]).
Specific chemical markers are generated from intact TRWP by pyrolysis of sample specimens. The chemical
markers consist of characteristic and specific pyrolysis dimeric fragments of passenger and truck tyre
tread polymers including butadiene rubber, styrene-butadiene rubber, and isoprene rubber. The polymer
fragments generated by sample pyrolysis are subsequently separated by gas chromatography (GC) and
identified by mass spectrometry (MS). The TRWP mass concentration is calculated based on market
average polymer use rates in tread, and prior characterization of the mineral content of TRWP. Rubber
polymer specificity is achieved by quantification of dimeric polymer fragments consisting of two monomer
units (see References [7], and [8]). Repeatability is achieved by the use of a deuterated internal standard of
similar polymeric structure to the tyre tread polymers. The internal standard corrects for variable analyte
recovery caused by sample size, matrix effects, and temporal variation in instrument response. The method
is suitable for monitoring changes in soil or sediment TRWP concentrations over time.
NOTE Tyre and road wear particles are a discrete mass of elongated particles generated at the frictional interface
between the tyre and roadway surface during the service life of a tyre. The particles consist of tyre tread enriched
with mineral encrustations from the roadway surface.

vi
FINAL DRAFT International Standard ISO/FDIS 21396:2026(en)
Rubber — Determination of the mass concentration of tyre
and road wear particles (TRWP) in soil and sediment —
Pyrolysis-gas chromatography/mass spectrometry (GC/MS)
method
WARNING 1 — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is
the responsibility of the user to establish appropriate safety and health practices.
WARNING 2 — Certain procedures specified in this document can involve the use or generation of
substances, or the generation of waste, that can constitute a local environmental hazard. Reference
should be made to appropriate documentation on safe handling and disposal after use.
1 Scope
This document specifies a method for the determination of the mass concentration (μg/g) of tyre and road
wear particles (TRWP) in soil or sediment environmental samples.
This document establishes principles for soil or sediment sample collection, the generation of pyrolysis
fragments from the sample, and the quantification of the generated polymer fragments.
This document is applicable to the environmental samples from soil or sediment.
This document is not applicable to the environmental samples from ambient air and ambient water.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 17257, Rubber — Identification of polymers — Pyrolytic gas-chromatographic method using mass-
spectrometric detection
ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
deuterated internal standard
polymer made of monomer containing at least one deuterium molecule added to a sample in a fixed amount
that is nearly identical to the target analyte used to correct for instrument drift and matrix interference

ISO/FDIS 21396:2026(en)
3.2
dry mass
mass of solid dried in an oven for a specified time and at a specified temperature
3.3
wet mass
mass of solid before drying in an oven
3.4
monitoring
repeated measurement to follow changes over a period of time
3.5
per cent dry mass
dry mass (3.2) of sample solids expressed as a percentage of the sample wet mass (3.3)
3.6
pyrolysis analysis
decomposition of organic polymeric molecules into characteristic fragments separated by gas
chromatography (GC) and quantified by mass spectrometry (MS)
4 Principle
Tyre tread polymer is quantified using internal standard calibration and the peak area of characteristic
fragment ions corresponding to dimers of the raw polymer by pyrolysis-GC/MS. The thermal decomposition
1)
products of cross-linked natural rubber (NR) (CAS Registry Number® 9006-04-6), styrene-butadiene
rubber (SBR) (CAS RN® 9003-55-8) and butadiene rubber (BR) (CAS RN® 9003-17-2) polymers depend
on the abundance of polymers in the sample. SBR pyrolysis generates butadiene (CAS RN® 106-99-
0), 4-vinylcyclohexene (butadiene dimer;VCH) (CAS RN® 100-40-3), styrene (CAS RN® 100-42-5), and
4-phenylcyclohexene (PCH) (CAS RN® 4994-16-5), whereas BR generates butadiene monomer and VCH
(see Reference [9]). NR is associated with isoprene (CAS RN® 78-79-5) monomer and dipentene (isoprene
dimer;DP) (CAS RN® 138-86-3). Synthetic poly(1,4-isoprene) rubber (IR) (CAS RN® 9003-31-0), a structural
analogue of NR, also yields dipentene upon pyrolysis, and is used in calibration standards. Quantification of
the synthetic fraction (SBR and BR) by the VCH marker is preferred based on the increased response ratio
and contribution as compared to the PCH marker, which estimates the synthetic fraction based on SBR only
(see Reference [11]).
The dimer fragments have good specificity for rubber polymers, whereas both anthropogenic and natural
organic substances are sources of the monomer markers (see Reference [7]). Therefore, the monomeric
pyrolysis marker compounds are subject to interference from non-TRWP environmental sources, and are
not suitable for quantification of TRWP mass concentration in soil or sediment. One well-known example is
styrene, which is generated from pyrolysis of both SBR and diesel exhaust particles (see Reference [10]). The
tyre polymers and pyrolysis fragment dimers used for quantification of TRWP are shown in Table 1.
1) CAS Registry Number® is a trademark of the American Chemical Society (ACS). This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of the product named. Equivalent
products may be used if they can be shown to lead to the same results.

ISO/FDIS 21396:2026(en)
Table 1 — Dimeric pyrolysis products of tyre rubber polymer
Polymer formula Dimer
5 Reagents and materials
Use only reagents of recognized analytical grade.
5.1 Chloroform, analytical grade (non-deuterated CAS RN® 67-66-3 or deuterated CAS RN® 865-49-6).
5.2 Helium, purity 99,999 5 % by volume. (CAS RN® 7440-59-7).
5.3 Potassium hydroxide 10 % (100 g/l), purity >86 % by volume. (CAS RN® 1310-58-3).
5.4 Purified water, Type I ultrapure.
5.5 Deuterated poly(1,4-isoprene) (d-IR), for internal standard.
5.6 Deuterated polystyrene polybutadiene (d-PSPB), for internal standard.
5.7 Poly(1,4-isoprene) rubber (IR) (CAS RN® 9003-31-0), for calibration polymer.
5.8 Styrene-butadiene rubber (SBR), for calibration polymer.
6 Apparatus
6.1 Soil or sediment sampling — Equipment and consumable supplies
6.1.1 Sampling device
The sampling device shall be suitable for the collection of soil or sediment samples. Suitable devices include
pre-cleaned stainless steel hand trowels, coring tools, or clamshell dredge devices. The collection of a
sediment sample with a clamshell dredge device is illustrated in Figure 1.

ISO/FDIS 21396:2026(en)
Figure 1 — Collection of sample with clamshell dredge device
6.1.2 Sample containers.
Samples shall be collected in clean sample containers supplied by the laboratory, or clean sample container
handled in a manner consistent with laboratory standard operating procedures. The placement of a soil
sample into a sample container with a trowel is illustrated in Figure 2.
Figure 2 — Placement of sample in container with trowel
6.2 Equipment for analysis
6.2.1 Laboratory oven, for drying field collected sample(s) in a suitably clean laboratory-supplied
container.
6.2.2 Sieve, for removing large aggregates unsuitable for the pyrolyser unit. The nominal opening for dry
sieving shall be 1 mm as specified in ISO 3310-1.
6.2.3 Precision balance, for determination of sample mass as collected, after oven drying, and after
dry sieving. The balance shall be accurate to at least 0,1 mg and be maintained, calibrated, and certified in
accordance with the manufacturer’s recommendations.

ISO/FDIS 21396:2026(en)
6.2.4 Analytical balance, for weighing sample, internal standard, and calibration polymer for
measurement. The balance shall be accurate to at least 0,01 mg and be maintained, calibrated, and certified
in accordance with the manufacturer’s recommendations.
6.2.5 Pyrolytic gas-chromatographic equipmentusing mass-spectrometric detection, conforming to
ISO 17257.
a) Pyrolysis system.
b) Gas chromatograph equipped with chromatographic column.
c) Mass detector in electronic impact mode.
6.2.5.1 Pyrolysis system, with a single-use or reusable sample holder shall be selected in accordance
with the manufacturer's recommendation. Examples of common pyrolyser systems paired with a gas
chromatograph/mass spectrometer are provided in ISO 17257 and include micro-furnace with quartz
tube and Curie point with holder. Platinum filament (resistive) pyrolysers shall not be used for quantitative
pyrolysis as they do not meet the requirement of this method (see Reference [11]).
6.2.5.2 Gas chromatograph, maintained in accordance with the manufacturer’s instructions and having
a column with the characteristics specified below:
— the column length: 25 m to 60 m;
— the column diameter: 0,25 mm to 0,35 mm;
— stationary phase of the column: 5 % diphenyl-, 95 % polydimethylsiloxane;
— film thickness of the column: 0,20 µm to 1,0 µm.
6.2.5.3 Mass spectrometer, maintained in accordance with the manufacturer’s instructions. Examples
include quadrupole mass spectrometer, magnetic-sector-type mass spectrometer or any other suitable type
of electron ionization instrument.
7 Specimen preparation laboratory
The specimen preparation laboratories and sample containers selected for analysis shall be sufficiently
free of contamination that blank analyses demonstrate an absence of polymer. At least one laboratory blank
analysis shall be performed for each type of sample container used for sample collection, and following
modifications to laboratory standard operating procedures or equipment.
8 Measuring range
The range of SBR/BR polymer that can be determined in a soil or sediment sample is approximately 0,1 μg
to 150 μg, and the range of NR polymer that can be determined is approximately 0,1 μg to 75 μg. Assuming
a total sample mass of 0,020 g, this mass range corresponds to a TRWP concentration range in soil or
sediment of approximately 30 μg/g to 30 000 μg/g using VCH and DP markers or alternatively 60 μg/g to
75 000 μg/g using PCH and DP markers. The relative standard deviation of replicate sample concentrations
[12]
is approximately 30 % with mortar and pestle homogenization of 10,0 g to 50,0 g samples.
NOTE The TRWP concentration range is based on Formula (D.2). For example, the low end of the TRWP
concentration range is (0,1 μg × 0,36 ÷ 0,70 + 0,1 μg) ÷ 0,5 ÷ 0,5 ÷ 0,020 g = 30 μg/g. The first factor of 0,36 ÷ 0,70
accounts for the difference in total 1,4-butadiene content in calibration SBR as compared to the market average tread
SBR/BR. The second factor of 0,5 accounts for the polymer fraction in tyre tread. TRWP consists of tyre tread enriched
with mineral encrustations from the roadway surface. The third factor of 0,5 accounts for the fraction of tyre tread in
TRWP.
ISO/FDIS 21396:2026(en)
9 Limit of detection
The TRWP limit of detection (LOD) depends on mass of sample pyrolysed, the sensitivity of the equipment
used, and blank levels realized by an individual laboratory. In practice, sampling constraints and the capacity
of the pyrolysis unit determine the lowest achievable LOD. For a nominal sample mass of 0,020 0 g, an LOD of
approximately 30 μg/g TRWP in soil or sediment has been reported (see Reference [2]).
10 Procedure
10.1 General
The method is defined for a sample mass of oven-dried soil or sediment suitable for the pyrolyser unit.
Thermal energy is applied to a sample encapsulated in a pyrolyser in the absence of oxygen to decompose
the sample. Secondary reactions are minimized by rapid heating of the pyrolyser to the target temperature.
The nominal sample mass for the example pyrolysis unit described in Annex B is 0,020 0 g. The sample
collection and laboratory pyrolysis-GC/MS procedure consists of the following six steps and is described in
10.2 to 10.6 respectively:
a) sample collection;
b) deuterated internal standard preparation;
c) calibration curve preparation;
d) sample preparation;
e) sample pyrolysis with polymer decomposition under defined thermal conditions;
f) dimer measurement using gas-chromatographic separation and mass spectrometry.
The procedure relies on deuterated polymer internal standards to increase the precision and accuracy of
the measured TRWP concentration. The internal standard is used to correct for matrix effects that affect
polymer pyrolysis and fragment recovery. The internal standard also corrects for changes in the mass
spectrometer ion source condition and fluctuations in carrier gas flow rates. The internal standards are
deuterated polyisoprene (d-IR) and deuterated polystyrene polybutadiene (d-PSPB), which are polymers
labelled with the minor stable hydrogen isotope deuterium. The pyrolysis-GC/MS thermal decomposition
products of d-IR and d-PSPB can be discriminated based on retention time and mass to charge ratio from the
DP, VCH and PCH markers associated with NR, SBR/BR, and SBR, respectively.
10.2 Sample collection
A soil or sediment sample is collected in clean laboratory supplied or approved sample containers. The sample
shall be collected using a clean device suitable for the collection of soil or sediment samples, as described in
6.1.1. The standard operating procedure for sample collection shall be approved by the laboratory. A chain-
of-custody form documenting sample collection and relinquishment shall be maintained. A soil or sediment
mass of at least 10,0 g to 50,0 g should be collected to ensure adequate homogenization.
10.3 Deuterated internal standard preparation
Deuterated standards d-IR and d-PSPB of known purity shall be obtained prior to analysis (see Table 2). The
purity of the standards shall be sufficiently high to prevent interference for TRWP sample concentrations at
or above the detection limit or reporting limit of the analysis.
A recipe for stock internal standard solution preparation that may be used is described in Annex A.
Alternative recipes may be used to meet the objectives of the analysis. To prepare the stock solutions, raw
d-IR or d-PSPB polymer is weighed, placed in a graduated flask. Chloroform shall be poured to two-thirds of
the total volume specified in the recipe. Deuterated standard dissolution can be achieved by various means,
provided the laboratory verifies that the standard is fully dissolved, and the solution is homogeneous.
Immediately prior to analysis, chloroform shall be added to achieve the total volume specified in the recipe

ISO/FDIS 21396:2026(en)
and solution is shaken to ensure homogeneity. The raw polymers shall be dissolved in chloroform prior to
the day of analysis to ensure sufficient time for dissolution or by mechanically assisted dissolution, such as
orbital shaking or stirring. The laboratory shall verify that the standard is fully dissolved, and the solution
is homogeneous. Deuterated chloroform can be used as a solvent to mitigate the possibility of deuterated
hydrogen exchange.
Table 2 — Pyrolysis-GC/MS polymers, markers and internal standards
Tyre polymer
Attribute
SBR
NR SBR, BR
(Alternate for SBR, BR)
Pyrolysis marker DP VCH PCH
Pyrolysis marker retention
~17 ~10 ~23
a
time (min)
Target m/z of marker 68 54 104
b
Diagnostic m/z of marker 136, 93 108, 79 158
Poly([deuterated sty-
Deuterated
rene-d8]-CO-[deuterated
Internal standard poly(1,4-iso- [d-PSPB]
butadiene = d6], random
prene-d8) [d-IR]
[d-PSPB]
Target m/z of internal stand-
76 60 112
b
ard
Poly(1,4-isoprene)
Calibration polymer SBR SBR
rubber (IR)
c
Calibration points (μg) 1; 5; 10; 25; 75 2; 10; 20; 50; 150 2; 10; 20; 50; 150
a
Retention times are approximate based on the example conditions in Annex B. Retention times can vary depending
on laboratory conditions, instrument configuration, column dimensions, and temperature program.
b
It shall be verified that the absence of a coeluting interfering compound for each marker and standard in the selection
of markers and pre-treatment protocol for quantitation.
c
Alternative calibration points can be used to meet the objectives of the analysis.
10.4 Calibration curve preparation
10.4.1 Stock solutions
Stock chloroform solutions of raw polymers, including synthetic poly(1,4-isoprene) rubber (IR) and SBR,
shall be prepared for the calibration curves. Calibration polymers of known or obtainable microstructure
shall be selected since the microstructure affects the result of the calibration curve. Commercially available
SBR calibration polymer products such as SBR 1500 grade can be used. It is also possible to use polystyrene-
polybutadiene (PSPB) random copolymers. Recipes for stock calibration and internal standard solution
preparation that should be used are described in Annex A. Alternative recipes may be used to meet the
objectives of the analysis. To prepare the stock solutions, raw IR or SBR polymer is weighed and placed
in a graduated flask. Chloroform shall be poured to two-thirds of the total volume specified in the recipe.
Dissolution of polymer can be achieved by various means, provided the laboratory verifies that the standard
is fully dissolved, and the solution is homogeneous. Immediately prior to analysis, chloroform is added to
achieve the total volume specified in the recipe and shaken sufficiently to homogenize. The chloroform
solution is added to the sample holder by micropipette, and evaporated to dryness at room temperature for
30 min. Calibration standard polymers shall be stored in a cool and dark condition.
10.4.2 Calibration curves
An internal standard calibration curve shall be prepared by least squares regression with quadratic fit
according to the instrument conditions described in 6.2 and Annex B. Synthetic IR and SBR polymer are used
as surrogates in the calibration curve preparation for NR and SBR/BR tread rubber, respectively. The mass
of polymer analysed for the calibration samples should be 1,00 μg to 75,0 μg for IR and 2,00 μg to 150 μg
for SBR (see Table 2). Alternative calibration points may be used to meet the objectives of the analysis. The

ISO/FDIS 21396:2026(en)
lower limit of calibration shall be equal to the limit of quantification (LOQ) for the method. The instrument
signal to noise ratio (S/N) shall be equal to three at the LOD and greater than or equal to five at the LOQ.
The internal standard calibration curves are generated by plotting the peak area response ratio as a
function of the amount ratio using a quadratic regression. The response ratio is the ratio of the integrated
peak area of the calibration standard pyrolysis marker to the integrated peak area of the internal standard
pyrolysis marker. The amount ratio is the ratio of the mass of the calibration standard to the added mass of
the internal standard.
The acceptance criterion for the calibration curves is a coefficient of determination (r ) greater than or equal
to 0,99. Instrument software should be used to quantify peak areas of the deuterated internal standard
pyrolysis markers and calibration standard pyrolysis markers. Peak areas shall be individually inspected
for quality control. Stock solutions shall be replaced no more than three months after initial preparation.
Calibration curve standards shall be monitored by comparison to the initial calibration. The acceptance
criteria for calibration curves shall be a per cent drift of less than 20 % before and after each analysis series,
using Formula (1):
 MM 
tc
d�� 100 (1)
 
M
 
t
where
d is drift (%);
M is the measured mass of continuing calibration verification standard based on the calibration
c
standard solution recipe;
M is the theoretical mass of continuing calibration verification standard as measured by the
t
instrument.
Fresh calibration curve standards shall be prepared prior to each new analysis sequence or if drift exceeds
20 %.
Sample calibration curves and pyrograms are provided in Annex C. SBR calibration curves should be
prepared for the VCH and PCH marker. Quantification of the synthetic fraction (SBR and BR) by the VCH
marker is preferred as explained in Clause 4. The PCH marker may be used as a diagnostic or secondary
quantitation marker.
10.5 Sample preparation
10.5.1 General
Samples shall be prepared for pyrolysis analysis in an environment free of polymer contamination. Samples
shall not be prepared for analysis until acceptable blank analyses have been completed.
10.5.2 Oven drying
The soil or sediment sample shall be placed in a suitable container and dried in a laboratory oven for 24 h
at 105 °C. Following drying, the sample shall be cooled to room temperature in a desiccator or other means
to obtain conditions of controlled humidity before weighing. The sample wet mass and dry mass shall be
recorded, and the per cent dry mass determined as shown in Formula (2). The dry mass shall be weighed
after the temperature of dried sample become room temperature.
M
d
P 100 (2)
dm
M
w
where
P is per cent dry mass (%);
dm
M is wet mass of sample (g);
w
M is dry mass of sample (g).
d
ISO/FDIS 21396:2026(en)
10.5.3 Sieving and homogenization
After drying, the sample should be sieved to remove large aggregates unsuitable for the pyrolyser. The
nominal opening for dry sieving shall be 1 mm as specified in ISO 3310-1. The sieved sample (10–50 g)
shall be pre-mixed to promote initial particle distribution. Following this, the sample shall be homogenized
using a clean mortar and pestle for a single session of 2–5 minutes, applying consistent pressure until visual
uniformity is achieved. Over-grinding shall be avoided.
10.5.4 Sample pre-treatment
Sample pre-treatment shall be performed to eliminate potential eluting compound interference from natural
and synthetic organic compounds (see Reference [12]). A 0,500 g dry, sieved and homogenized sample mass
and 10 ml of potassium hydroxide aqueous solution described in 5.3 shall be added to a sealed polypropylene
tube and incubated at 60 °C for 24 h. Following incubation, samples shall be collected on alkaline-resistant
membrane filter such as hydrophilic PTFE filter and be washed with purified water to neutral pH. The mass
fraction loss of mass attributable to the digestion shall be calculated after oven drying the treated sample at
105 °C for 3 h as shown in Formula (3).
MM�
d,id,f
F  (3)
p
M
d,i
where
F is the dry mass fraction loss in the sample pre-treatment process;
p
M is the initial dry mass of sample before pre-treatment (g);
d,i
M is the final dry mass of sample after pre-treatment (g).
d,f
The mass concentration of TRWP adjusted for sample mass loss in pre-treatment may be calculated as
shown in Annex E.
When sample pre-treatment is performed, the collected sample shall be homogenized by a suitable method
such as mortar and pestle before the analysis.
10.6 Sample measurement
10.6.1 Sample mass
Approximately 0,010 g to 0,020 g or a suitable mass of the dry-sieved and homogenized sample shall be
selected for pyrolysis analysis and placed in a sample holder compatible with the pyrolysis unit. The
analysed mass shall be appropriate for the pyrolyser and gas chromatography column split ratio.
10.6.2 Internal standard addition
The internal standards d-PSPB and d-IR shall be added to the sample in the same mass amounts as used in
the calibration curve preparation. The mass addition is 50,0 μg of d-PSPB and 25,0 μg d-IR in chloroform
solution for the typical calibration points shown in Annex A. The chloroform solution is added to the sample
by micropipette and evaporated to dryness at room temperature for 30 min.
10.6.3 Pyrolysis-GC/MS measurement
10.6.3.1 Pyrolysis system, operating at a temperature of 670 °C for 5 s in a helium atmosphere with an
induction time of less than 0,2 s. The sample holder shall be placed in the pyrolyser for thermal decomposition
analysis. The pyrolysis equipment and instrument characteristics are described in 6.2.5. An informative
description of conditions for one type of pyrolyser that may be used is presented in Annex B. Comparative
examples of instrument conditions for the micro-furnace with quartz tube and Curie point pyrolyser are
provided in Annex B. Equipment maintenance shall be performed in accordance with the manufacturer’s
instructions. A record of analysis and equipment maintenance shall be maintained in a permanent log.

ISO/FDIS 21396:2026(en)
10.6.3.2 Gas chromatograph/mass spectrometer, operated in accordance with the manufacturer’s
instructions. GC/MS equipment and instrument characteristics are described in 6.2.5. An informative
description of instrument conditions for the micro-furnace with quartz tube or Curie point with holder
are presented in Annex B (see Reference [11] and [12]). For quantitative analysis, SIM mode or SIM/Scan
mode is preferable. Equipment maintenance and equipment tuning shall be performed in accordance with
the manufacturer’s instructions. A record of analysis and equipment maintenance shall be maintained in a
permanent log. GC/MS equipment shall be well-maintained to ensure reliable results, and the calibration
curve shall be verified before and after each analysis series.
10.6.3.3 Gas chromatograph, conditions as specified below:
— carrier gas flow rate: 1,0 ml/min to 2,0 ml/min in constant flow mode, unless otherwise specified by the
instrument manufacturer;
— injector temperature: 300 °C;
— oven temperature programme satisfying the desired heating rate and maintaining low temperature,
such as: 40 °C (1 min) - (5 °C /min) - 125 °C - (20 °C /min) - 205 °C - (5 °C /min) - 210 °C - (25 °C /min) -
300 °C (10 min).
10.6.3.4 Mass spectrometer, conditions as specified below:
— interface temperature: 300 °C to 350 °C;
— ionization method: electron ionization;
— ion source temperature: 230 °C;
— ionizing voltage: 70 eV;
— scan range (if scan mode is applied): mass/charge ratio: 35 m/z to 500 m/z.
The following tyre polymer and internal standard deuterated polymer thermal decomposition fragments
generated by the pyrolyser shall be quantified by GC/MS:
a) DP from NR;
b) VCH from SBR and BR;
c) PCH from SBR;
d) deuterated DP (d-DP) from d-IR;
e) deuterated VCH (d-VCH) from d-PSPB;
f) d
...

ISO/FDIS 21396:2026(en)
ISO /TC 45/WG 16
Secretariat: DSM
Date: 2026-02-2006-08
Rubber — Determination of the mass concentration of tyre and road
wear particles (TRWP) in soil and sediment — Pyrolysis-gas
chromatography/mass spectrometry (GC/MS) method
Caoutchouc — Détermination de la concentration massique en particules ded'usure des pneumatiques et
d'usure de la route (TRWPTWRP) dans le sol et les sédiments — Méthode par pyrolyse-GC/MS
FDIS stage
ISO/DIS FDIS 21396:2025(E2026(en)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO'sISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email:
E-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO/FDIS 21396:2026(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents and materials . 3
6 Apparatus . 4
6.1 Soil or sediment sampling — Equipment and consumable supplies . 4
6.2 Equipment for analysis . 5
7 Specimen preparation laboratory . 6
8 Measuring range . 6
9 Limit of detection . 6
10 Procedure . 7
10.1 General . 7
10.2 Sample collection . 7
10.3 Deuterated internal standard preparation . 7
10.4 Calibration curve preparation . 8
10.5 Sample preparation . 9
10.6 Sample measurement . 10
11 Analysis . 12
11.1 General . 12
11.2 Tyre and road wear particles/limit of detection (TRWP LOD) . 12
11.3 Quantity of tyre polymer in the sample . 12
11.4 Mass concentration of TRWP . 12
12 Performance characteristics . 13
12.1 General . 13
12.2 Specific performance characteristics . 13
13 Test report . 13
Annex A (informative) Recipe for calibration curves and stock solutions . 15
Annex B (informative) Instrument conditions . 17
Annex C (informative) Representative calibration curves and total ion pyrograms . 20
Annex D (informative) Calculation of tyre and road wear particle (TRWP) detection limits . 27
Annex E (normative) Calculation of results using dimer markers . 29
Annex F (informative) Precision . 34
Bibliography . 36

iii
ISO/DIS FDIS 21396:2025(E2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO [had/had not] received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that this
may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products.
This secondfirst edition cancels and replaces the first edition (ISO/TS 21396:2017), which has been
technically revised.
The main changes are as follows:
— — addition of information regarding instrument conditions for the microfurnace pyrolyser and resistive
pyrolyser to 6.2.5.16.2.5.1;;
— — addition of recommendations for sample chemical pre-treatment to 10.5.410.5.4;;
— — revision of the calculation method to account for differences in elastomer microstructure between
calibration standards and marketplace average tread;
— — addition of 4-phenylcyclohexene marker to 4., 8., 10.1, 10.3, 10.4.2, 10.6.3.4, 11.1, 11.4, Annex C4., 8.,
10.1, 10.3, 10.4.2, 10.6.3.4, 11.1, 11.4, Annex C, Annex D, Annex D and Annex EAnnex E .
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO/FDIS 21396:2026(en)
Introduction
Tyre and road wear particles (TRWP) are formed as a result of tread abrasion from the road surface, and
subsequent particle release to the environment. TRWP consist of tyre tread particles which include
incorporated material from the road surface (see Reference [1] [1]).). The elastomeric fraction in TRWP
contained in soil or sediment materials is quantified in this document by direct pyrolysis-GC/MS (gas
chromatography/mass spectrometry) analysis. Mass concentration can be expressed on the basis of the
rubber polymer, tyre tread, or TRWP. This method has been used to measure the TRWP concentration in soil
and sediment samples (see References [2],[3] [2], [3],, and[4] [4]).). The airborne concentration of TRWP in
the PM and PM fraction has also been characterized by a similar method (see References [5],[6] [5], [6],,
2.5 10
and[14] [14]).).
Specific chemical markers are generated from intact TRWP by pyrolysis of sample specimens. The chemical
markers consist of characteristic and specific pyrolysis dimeric fragments of passenger and truck tyre tread
polymers including butadiene rubber, styrene-butadiene rubber, and isoprene rubber. The polymer fragments
generated by sample pyrolysis are subsequently separated by gas chromatography (GC) and identified by
mass spectrometry (MS). The TRWP mass concentration is calculated based on market average polymer use
rates in tread, and prior characterization of the mineral content of TRWP. Rubber polymer specificity is
achieved by quantification of dimeric polymer fragments consisting of two monomer units (see References [7]
[7],, and[8] [8]).). Repeatability is achieved by the use of a deuterated internal standard of similar polymeric
structure to the tyre tread polymers. The internal standard corrects for variable analyte recovery caused by
sample size, matrix effects, and temporal variation in instrument response. The method is suitable for
monitoring changes in soil or sediment TRWP concentrations over time.

NOTE Tyre and road wear particles are a discrete mass of elongated particles generated at the frictional interface
between the tyre and roadway surface during the service life of a tyre. The particles consist of tyre tread enriched with
mineral encrustations from the roadway surface.
v
DRAFT International Standard ISO/FDIS 21396:2026(en)

Rubber — Determination of the mass concentration of tyre and road
wear particles (TRWP) in soil and sediment — Pyrolysis-gas
chromatography/mass spectrometry (GC/MS) method
WARNING 1 — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is
the responsibility of the user to establish appropriate safety and health practices.
WARNING 2 — Certain procedures specified in this document can involve the use or generation of
substances, or the generation of waste, that can constitute a local environmental hazard. Reference
should be made to appropriate documentation on safe handling and disposal after use.
1 Scope
This document specifies a method for the determination of the mass concentration (μg/g) of tyre and road
wear particles (TRWP) in soil or sediment environmental samples.
This document establishes principles for soil or sediment sample collection, the generation of pyrolysis
fragments from the sample, and the quantification of the generated polymer fragments.
This document is applicable to the environmental samples from soil or sediment.
This document is not applicable to the environmental samples from ambient air and ambient water.

2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 17257, Rubber — Identification of polymers — Pyrolytic gas-chromatographic method using mass-
spectrometric detection
ISO 3310--1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
—
ISO/DIS FDIS 21396:2025(E2026(en)
3.1 3.1
deuterated internal standard
polymer made of monomer containing at least one deuterium molecule added to a sample in a fixed amount
that is nearly identical to the target analyte used to correct for instrument drift and matrix interference
3.2 3.2
dry mass
mass of solid dried in an oven for a specified time and at a specified temperature
3.3 3.3
wet mass
mass of solid before drying in an oven
3.4 3.4
monitoring
repeated measurement to follow changes over a period of time
3.5 3.5
per cent dry mass
dry mass (3.2(3.2)) of sample solids expressed as a percentage of the sample wet mass (3.3(3.3))
3.6 3.6
pyrolysis analysis
decomposition of organic polymeric molecules into characteristic fragments separated by gas
chromatography (GC) and quantified by mass spectrometry (MS)
4 Principle
Tyre tread polymer is quantified using internal standard calibration and the peak area of characteristic
fragment ions corresponding to dimers of the raw polymer by pyrolysis-GC/MS. The thermal decomposition
1)
products of cross-linked natural rubber (NR) (CAS Registry Number® 9006-04-6), styrene-butadiene rubber
(SBR) (CAS RN® 9003-55-8) and butadiene rubber (BR) (CAS RN® 9003-17-2) polymers depend on the
abundance of polymers in the sample. SBR pyrolysis generates butadiene (CAS RN® 106-99-0), 4-
vinylcyclohexene (butadiene dimer;VCH) (CAS RN® 100-40-3), styrene (CAS RN® 100-42-5), and 4-
phenylcyclohexene (PCH) (CAS RN® 4994-16-5), whereas BR generates butadiene monomer and VCH (see
Reference [9] [9]).). NR is associated with isoprene (CAS RN® 78-79-5) monomer and dipentene (isoprene
dimer;DP) (CAS RN® 138-86-3). Synthetic poly(1,4-isoprene) rubber (IR) (CAS RN® 9003-31-0), a structural
analogue of NR, also yields dipentene upon pyrolysis, and is used in calibration standards. Quantification of
the synthetic fraction (SBR and BR) by the VCH marker is preferred based on the increased response ratio and
contribution as compared to the PCH marker, which estimates the synthetic fraction based on SBR only (see
Reference [11] [11]).).
The dimer fragments have good specificity for rubber polymers, whereas both anthropogenic and natural
organic substances are sources of the monomer markers (see Reference [7] [7]).). Therefore, the monomeric
pyrolysis marker compounds are subject to interference from non-TRWP environmental sources, and are not
suitable for quantification of TRWP mass concentration in soil or sediment. One well-known example is
styrene, which is generated from pyrolysis of both SBR and diesel exhaust particles (see Reference [10] [10]).).
The tyre polymers and pyrolysis fragment dimers used for quantification of TRWP are shown in
Table 1Table 1.
1)
CAS Registry Number® is a trademark of the American Chemical Society (ACS). This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of the product named. Equivalent
products may be used if they can be shown to lead to the same results.

ISO/FDIS 21396:2026(en)
Table 1 — Dimeric pyrolysis products of tyre rubber polymer
Polymer formula Dimer
5 Reagents and materials
Use only reagents of recognized analytical grade.
5.1 5.1 Chloroform, analytical grade. (non-deuterated CAS RN® 67-66-3 or deuterated CAS RN®
865-49-6).
5.2 5.2 Helium, purity 99,999 5 % by volume. (CAS RN® 7440-59-7).
5.3 5.3 Potassium hydroxide 10 % (100 g/l), purity >86 % by volume. (CAS RN® 1310-58-3).
5.4 5.4 Purified water, Type I ultrapure.
5.5 5.5 Deuterated poly(1,4-isoprene) (d-IR), for internal standard.
5.6 5.6 Deuterated polystyrene polybutadiene (d-PSPB), for internal standard.
5.7 5.7 Poly(1,4-isoprene) rubber (IR) (CAS RN® 9003-31-0), for calibration polymer.
5.8 5.8 Styrene-butadiene rubber (SBR), for calibration polymer.
ISO/DIS FDIS 21396:2025(E2026(en)
6 Apparatus
6.1 6.1 Soil or sediment sampling — Equipment and consumable supplies
6.1.1 6.1.1 Sampling device.
The sampling device shall be suitable for the collection of soil or sediment samples. Suitable devices include
pre-cleaned stainless steel hand trowels, coring tools, or clamshell dredge devices. The collection of a sediment
sample with a clamshell dredge device is illustrated in Figure 1Figure 1.

NOTE : Photograph reproduced with permission of the author

Figure 1 — Collection of sample with clamshell dredge device
6.1.2 6.1.2 Sample containers.
Samples shall be collected in clean sample containers supplied by the laboratory, or clean sample container
handled in a manner consistent with laboratory standard operating procedures. The placement of a soil
sample into a sample container with a trowel is illustrated in Figure 2Figure 2.
ISO/FDIS 21396:2026(en)
NOTE : Photograph reproduced with permission of the author

Figure 2 — Placement of sample in container with trowel
6.2 6.2 Equipment for analysis
6.2.1 6.2.1 Laboratory oven, for drying field collected sample(s) in a suitably clean laboratory-supplied
container.
6.2.2 6.2.2 Sieve, for removing large aggregates unsuitable for the pyrolyser unit. The nominal opening
for dry sieving shall be 1 mm as specified in ISO 3310-1.
6.2.3 6.2.3 Precision balance, for determination of sample mass as collected, after oven drying, and after
dry sieving. The balance shall be accurate to at least 0,1 mg and be maintained, calibrated, and certified in
accordance with the manufacturer’s recommendations.
6.2.4 6.2.4 Analytical balance, for weighing sample, internal standard, and calibration polymer for
measurement. The balance shall be accurate to at least 0,01 mg and be maintained, calibrated, and certified in
accordance with the manufacturer’s recommendations.
6.2.5 6.2.5 Pyrolytic gas-chromatographic equipment usingequipmentusing mass-spectrometric
detection, conforming to ISO 17257.
a) a) Pyrolysis system.
b) b) Gas chromatograph equipped with chromatographic column.
ISO/DIS FDIS 21396:2025(E2026(en)
c) c) Mass detector in electronic impact mode.
6.2.5.1 6.2.5.1 Pyrolysis system, with a single-use or reusable sample holder shall be selected
in accordance with the manufacturer's recommendation. Examples of common pyrolyser systems paired with
a gas chromatograph/mass spectrometer are provided in ISO 17257 and include micro-furnace with quartz
tube and Curie point with holder. Platinum filament (resistive) pyrolysers shall not be used for quantitative
pyrolysis as they do not meet the requirement of this method (see Reference [[11] [11]).]).
6.2.5.2 6.2.5.2 Gas chromatograph, maintained in accordance with the manufacturer’s
instructions and having a column with the characteristics specified below:
— — the column length: 25 m to 60 m;
— — the column diameter: 0,25 mm to 0,35 mm;
— — stationary phase of the column: 5 % diphenyl-, 95 % polydimethylsiloxane;
— — film thickness of the column: 0,20 µm to 1,0 µm.
6.2.5.3 6.2.5.3 Mass spectrometer, maintained in accordance with the manufacturer’s
instructions. Examples include quadrupole mass spectrometer, magnetic-sector-type mass spectrometer or
any other suitable type of electron ionization instrument.
7 Specimen preparation laboratory
The specimen preparation laboratories and sample containers selected for analysis shall be sufficiently free
of contamination that blank analyses demonstrate an absence of polymer. At least one laboratory blank
analysis shall be performed for each type of sample container used for sample collection, and following
modifications to laboratory standard operating procedures or equipment.
8 Measuring range
The range of SBR/BR polymer that can be determined in a soil or sediment sample is approximately 0,1 μg to
150 μg, and the range of NR polymer that can be determined is approximately 0,1 μg to 75 μg. Assuming a total
sample mass of 0,020 g, this mass range corresponds to a TRWP concentration range in soil or sediment of
approximately 30 μg/g to 30 000 μg/g using VCH and DP markers or alternatively 60 μg/g to 75 000 μg/g
using PCH and DP markers. The relative standard deviation of replicate sample concentrations is
[12]
approximately 30 % with mortar and pestle homogenization of 10,0 g to 50,0 g samples [12].
NOTE The TRWP concentration range is based on Formula (D.2) (D.2). For example, the low end of the TRWP
concentration range is (0,1 μg × 0,36 ÷ 0,70 + 0,1 μg) ÷ 0,5 ÷ 0,5 ÷ 0,020 g = 30 μg/g. The first factor of 0,36 ÷ 0,70
accounts for the difference in total 1,4-butadiene content in calibration SBR as compared to the market average tread
SBR/BR. The second factor of 0,5 accounts for the polymer fraction in tyre tread. TRWP consists of tyre tread enriched
with mineral encrustations from the roadway surface. The third factor of 0,5 accounts for the fraction of tyre tread in
TRWP.
9 Limit of detection
The TRWP limit of detection (LOD) depends on mass of sample pyrolysed, the sensitivity of the equipment
used, and blank levels realized by an individual laboratory. In practice, sampling constraints and the capacity
of the pyrolysis unit determine the lowest achievable LOD. For a nominal sample mass of 0,020 0 g, an LOD of
approximately 30 μg/g TRWP in soil or sediment has been reported (see Reference [2] [2]).).
ISO/FDIS 21396:2026(en)
10 Procedure
10.1 General
The method is defined for a sample mass of oven-dried soil or sediment suitable for the pyrolyser unit.
Thermal energy is applied to a sample encapsulated in a pyrolyser in the absence of oxygen to decompose the
sample. Secondary reactions are minimized by rapid heating of the pyrolyser to the target temperature. The
nominal sample mass for the example pyrolysis unit described in Annex BAnnex B is 0,020 0 g. The sample
collection and laboratory pyrolysis-GC/MS procedure consists of the following six steps and is described in
10.210.2 to 10.610.6 respectively:
a) a) sample collection;
b) b) deuterated internal standard preparation;
c) c) calibration curve preparation;
d) d) sample preparation;
e) e) sample pyrolysis with polymer decomposition under defined thermal conditions;
f) f) dimer measurement using gas-chromatographic separation and mass spectrometry.
The procedure relies on deuterated polymer internal standards to increase the precision and accuracy of the
measured TRWP concentration. The internal standard is used to correct for matrix effects that affect polymer
pyrolysis and fragment recovery. The internal standard also corrects for changes in the mass spectrometer
ion source condition and fluctuations in carrier gas flow rates. The internal standards are deuterated
polyisoprene (d-IR) and deuterated polystyrene polybutadiene (d-PSPB), which are polymers labelled with
the minor stable hydrogen isotope deuterium. The pyrolysis-GC/MS thermal decomposition products of d-IR
and d-PSPB can be discriminated based on retention time and mass to charge ratio from the DP, VCH and PCH
markers associated with NR, SBR/BR, and SBR, respectively.
10.2 Sample collection
A soil or sediment sample is collected in clean laboratory supplied or approved sample containers. The sample
shall be collected using a clean device suitable for the collection of soil or sediment samples, as described in
6.1.16.1.1. The standard operating procedure for sample collection shall be approved by the laboratory. A
chain-of-custody form documenting sample collection and relinquishment shall be maintained. A soil or
sediment mass of at least 10,0 g to 50,0 g should be collected to ensure adequate homogenization.

10.3 Deuterated internal standard preparation
Deuterated standards d-IR and d-PSPB of known purity shall be obtained prior to analysis (see
Table 2Table 2).). The purity of the standards shall be sufficiently high to prevent interference for TRWP
sample concentrations at or above the detection limit or reporting limit of the analysis.
A recipe for stock internal standard solution preparation that may be used is described in Annex AAnnex A.
Alternative recipes may be used to meet the objectives of the analysis. To prepare the stock solutions, raw d-
IR or d-PSPB polymer is weighed, placed in a graduated flask. Chloroform shall be poured to two-thirds of the
total volume specified in the recipe. Deuterated standard dissolution can be achieved by various means,
provided the laboratory verifies that the standard is fully dissolved, and the solution is homogeneous.
Immediately prior to analysis, chloroform shall be added to achieve the total volume specified in the recipe
and solution is shaken to ensure homogeneity. The raw polymers shall be dissolved in chloroform prior to the
ISO/DIS FDIS 21396:2025(E2026(en)
day of analysis to ensure sufficient time for dissolution or by mechanically assisted dissolution, such as orbital
shaking or stirring. The laboratory shall verify that the standard is fully dissolved, and the solution is
homogeneous. Deuterated chloroform can be used as a solvent to mitigate the possibility of deuterated
hydrogen exchange.
Table 2 — Pyrolysis-GC/MS polymers, markers and internal standards
Tyre polymer
Attribute
SBR
NR SBR, BR
(Alternate for SBR, BR)
Pyrolysis marker DP VCH PCH
Pyrolysis marker retention
~17 ~10 ~23
a
time (min)
Target m/z of marker 68 54 104
b
Diagnostic m/z of marker 136, 93 108, 79 158
Poly([deuterated styrene-
Deuterated
d8]-CO-[deuterated
Internal standard poly(1,4-isoprene- [d-PSPB]
butadiene = d6], random
d8) [d-IR]
[d-PSPB]
Target m/z of internal
76 60 112
b
standard
Poly(1,4-isoprene)
Calibration polymer SBR SBR
rubber (IR)
c
Calibration points (μg) 1; 5; 10; 25; 75 2; 10; 20; 50; 150 2; 10; 20; 50; 150
a
Retention times are approximate based on the example conditions in Annex B. Retention times can vary depending
on laboratory conditions, instrument configuration, column dimensions, and temperature program.
b
It shall be verified that the absence of a coeluting interfering compound for each marker and standard in the
selection of markers and pre-treatment protocol for quantitation.
c
Alternative calibration points can be used to meet the objectives of the analysis.

10.4 Calibration curve preparation
10.4.1 Stock solutions
Stock chloroform solutions of raw polymers, including synthetic poly(1,4-isoprene) rubber (IR) and SBR, shall
be prepared for the calibration curves. Calibration polymers of known or obtainable microstructure shall be
selected since the microstructure affects the result of the calibration curve. Commercially available SBR
calibration polymer products such as SBR 1500 grade can be used. It is also possible to use polystyrene-
polybutadiene (PSPB) random copolymers. Recipes for stock calibration and internal standard solution
preparation that should be used are described in Annex AAnnex A. Alternative recipes may be used to meet
the objectives of the analysis. To prepare the stock solutions, raw IR or SBR polymer is weighed and placed in
a graduated flask. Chloroform shall be poured to two-thirds of the total volume specified in the recipe.
Dissolution of polymer can be achieved by various means, provided the laboratory verifies that the standard
is fully dissolved, and the solution is homogeneous. Immediately prior to analysis, chloroform is added to
achieve the total volume specified in the recipe and shaken sufficiently to homogenize. The chloroform
solution is added to the sample holder by micropipette, and evaporated to dryness at room temperature for
30 min. Calibration standard polymers shall be stored in a cool and dark condition.
ISO/FDIS 21396:2026(en)
10.4.2 Calibration curves
An internal standard calibration curve shall be prepared by least squares regression with quadratic fit
according to the instrument conditions described in 6.26.2 and Annex BAnnex B. Synthetic IR and SBR
polymer are used as surrogates in the calibration curve preparation for NR and SBR/BR tread rubber,
respectively. The mass of polymer analysed for the calibration samples should be 1,00 μg to 75,0 μg for IR and
2,00 μg to 150 μg for SBR (see Table 2Table 2).). Alternative calibration points may be used to meet the
objectives of the analysis. The lower limit of calibration shall be equal to the limit of quantification (LOQ) for
the method. The instrument signal to noise ratio (S/N) shall be equal to three at the LOD and greater than or
equal to five at the LOQ.
The internal standard calibration curves are generated by plotting the peak area response ratio as a function
of the amount ratio using a quadratic regression. The response ratio is the ratio of the integrated peak area of
the calibration standard pyrolysis marker to the integrated peak area of the internal standard pyrolysis
marker. The amount ratio is the ratio of the mass of the calibration standard to the added mass of the internal
standard.
The acceptance criterion for the calibration curves is a coefficient of determination (r ) greater than or equal
to 0,99. Instrument software should be used to quantify peak areas of the deuterated internal standard
pyrolysis markers and calibration standard pyrolysis markers. Peak areas shall be individually inspected for
quality control. Stock solutions shall be replaced no more than three months after initial preparation.
Calibration curve standards shall be monitored by comparison to the initial calibration. The acceptance
criteria for calibration curves shall be a per cent drift of less than 20 % before and after each analysis series,
using Formula (1)Formula (1)::
| |
𝑀𝑀 −𝑀𝑀 |𝑀𝑀 −𝑀𝑀 |
𝑡𝑡 𝑐𝑐 𝑡𝑡 𝑐𝑐
𝑑𝑑 = � � � × = ( � ) × 100 (1)
𝑀𝑀 𝑀𝑀
𝑡𝑡 𝑡𝑡
where
d is drift (%);
Mc is the measured mass of continuing calibration verification standard based on the calibration standard solution
recipe;
Mt is the theoretical mass of continuing calibration verification standard as measured by the instrument.
Fresh calibration curve standards shall be prepared prior to each new analysis sequence or if drift exceeds
20 %.
Sample calibration curves and pyrograms are provided in Annex CAnnex C. SBR calibration curves should be
prepared for the VCH and PCH marker. Quantification of the synthetic fraction (SBR and BR) by the VCH
marker is preferred as explained in Clause 4Clause 4. The PCH marker may be used as a diagnostic or
secondary quantitation marker.

10.5 Sample preparation
10.5.1 General
Samples shall be prepared for pyrolysis analysis in an environment free of polymer contamination. Samples
shall not be prepared for analysis until acceptable blank analyses have been completed.
10.5.2 Oven drying
The soil or sediment sample shall be placed in a suitable container and dried in a laboratory oven for 24 h at
105 °C. Following drying, the sample shall be cooled to room temperature in a desiccator or other means to
obtain conditions of controlled humidity before weighing. The sample wet mass and dry mass shall be
ISO/DIS FDIS 21396:2025(E2026(en)
recorded, and the per cent dry mass determined as shown in Formula (2)Formula (2). The dry mass shall be
weighed after the temperature of dried sample become room temperature.
𝑀𝑀
𝑑𝑑
𝑃𝑃 = × 100 (2)
dm
𝑀𝑀
𝑤𝑤
where
Pdm is per cent dry mass (%);
Mw is wet mass of sample (g);
M is dry mass of sample (g).
d
10.5.3 Sieving and homogenization
After drying, the sample should be sieved to remove large aggregates unsuitable for the pyrolyser. The
nominal opening for dry sieving shall be 1 mm as specified in ISO 3310-1. The sieved sample (10–50 g) shall
be pre-mixed to promote initial particle distribution. Following this, the sample shall be homogenized using a
clean mortar and pestle for a single session of 2–5 minutes, applying consistent pressure until visual
uniformity is achieved. Over-grinding shall be avoided.
10.5.4 Sample pre-treatment
Sample pre-treatment shall be performed to eliminate potential eluting compound interference from natural
and synthetic organic compounds (see Reference 12 [12]).). A 0,500 g dry, sieved and homogenized sample
mass and 10 ml of potassium hydroxide aqueous solution described in 5.35.3 shall be added to a sealed
polypropylene tube and incubated at 60 °C for 24 h. Following incubation, samples shall be collected on
alkaline-resistant membrane filter such as hydrophilic PTFE filter and be washed with purified water to
neutral pH. The mass fraction loss of mass attributable to the digestion shall be calculated after oven drying
the treated sample at 105 °C for 3 h as shown in Formula (3)Formula (3).
𝑀𝑀 − 𝑀𝑀 𝑀𝑀 − 𝑀𝑀
d,i d,f d,i d,f
𝐹𝐹 = (3)
𝑝𝑝
𝑀𝑀 𝑀𝑀
d,i d,i
where
𝐹𝐹 is the dry mass fraction loss in the sample pre-treatment process;
𝑝𝑝
𝑀𝑀 is the initial dry mass of sample before pre-treatment (g);
d,i
𝑀𝑀 is the final dry mass of sample after pre-treatment (g).
d,f
The mass concentration of TRWP adjusted for sample mass loss in pre-treatment may be calculated as shown
in Annex EAnnex E.
When sample pre-treatment is performed, the collected sample shall be homogenized by a suitable method
such as mortar and pestle before the analysis.
10.6 Sample measurement
10.6.1 Sample mass
Approximately 0,010 g to 0,020 g or a suitable mass of the dry-sieved and homogenized sample shall be
selected for pyrolysis analysis and placed in a sample holder compatible with the pyrolysis unit. The analysed
mass shall be appropriate for the pyrolyser and gas chromatography column split ratio.
10.6.2 Internal standard addition
The internal standards d-PSPB and d-IR shall be added to the sample in the same mass amounts as used in the
calibration curve preparation. The mass addition is 50,0 μg of d-PSPB and 25,0 μg d-IR in chloroform solution
ISO/FDIS 21396:2026(en)
for the typical calibration points shown in Annex AAnnex A. The chloroform solution is added to the sample
by micropipette and evaporated to dryness at room temperature for 30 min.
10.6.3 Pyrolysis-GC/MS measurement
10.6.3.1 10.6.3.1 Pyrolysis system, operating at a temperature of 670 °C for 5 s in a helium
atmosphere with an induction time of less than 0,2 s. The sample holder shall be placed in the pyrolyser for
thermal decomposition analysis. The pyrolysis equipment and instrument characteristics are described in
6.2.56.2.5. An informative description of conditions for one type of pyrolyser that may be used is presented
in Annex BAnnex B. Comparative examples of instrument conditions for the micro-furnace with quartz tube
and Curie point pyrolyser are provided in Annex BAnnex B. Equipment maintenance shall be performed in
accordance with the manufacturer’s instructions. A record of analysis and equipment maintenance shall be
maintained in a permanent log.
10.6.3.2 10.6.3.2 Gas chromatograph/mass spectrometer, operated in accordance with the
manufacturer’s instructions. GC/MS equipment and instrument characteristics are described in 6.2.56.2.5.
An informative description of instrument conditions for the micro-furnace with quartz tube or Curie point
with holder are presented in Annex BAnnex B (see Reference [[11] [11]] and [[12][12]).]). For quantitative
analysis, SIM mode or SIM/Scan mode is preferrablepreferable. Equipment maintenance and equipment
tuning shall be performed in accordance with the manufacturer’s instructions. A record of analysis and
equipment maintenance shall be maintained in a permanent log. GC/MS equipment shall be well-maintained
to ensure reliable results, and the calibration curve shall be verified before and after each analysis series.
10.6.3.3 10.6.3.3 Gas chromatograph, conditions as specified below:
— — carrier gas flow rate: 1,0 ml/min to 2,0 ml/min in constant flow mode, unless otherwise specified by
the instrument manufacturer;
— — injector temperature: 300 °C;
— — oven temperature programme satisfying the desired heating rate and maintaining low temperature,
such as: 40 °C (1 min) - (5 °C /min) - 125 °C - (20 °C /min) - 205 °C - (5 °C /min) - 210 °C - (25 °C /min) -
300 °C (10 min).
10.6.3.4 10.6.3.4 Mass spectrometer, conditions as specified below:
— — interface temperature: 300 °C to 350 °C;
— — ionization method: electron ionization;
— — ion source temperature: 230 °C;
— — ionizing voltage: 70 eV;
— — scan range (if scan mode is applied): mass/charge ratio: 35 m/z to 500 m/z.
The following tyre polymer and internal standard deuterated polymer thermal decomposition fragments
generated by the pyrolyser shall be quantified by GC/MS:
a) a) DP from NR;
b) b) VCH from SBR and BR;
c) c) PCH from SBR;
d) d) deuterated DP (d-DP) from d-IR;
e) e) deuterated VCH (d-VCH) from d-PSPB;
ISO/DIS FDIS 21396:2025(E2026(en)
f) f) deuterated PCH (d-PCH) from d-PSPB.
The mass to charge ratio for the thermal decomposition products is specified in Table 2Table 2.
11 Analysis
11.1 General
The mass and concentration of TRWP in soil or sediment shall be determined by using GC/MS pyrograms of
the dimer fragments DP and VCH. The PCH fragment may be used as an alternate or confirmatory dimer
fragment replacing the VCH fragment. The sample analysis consists of the following three calculations
described in 11.211.2 to 11.411.4,, and specified in Annex DAnnex D and Annex EAnnex E::
a) a) TRWP LOD;
b) b) quantity of tyre polymer in the sample;
c) c) mass concentration of TRWP in the sample.
11.2 TRWP LOD (tyreTyre and road wear particles/limit of detection (TRWP LOD)
The polymer MDL (μg) shall be estimated based on the instrument S/N ratio and studies as specified in
10.4.210.4.2. The polymer detection limit shall be used to calculate the minimum detectable TRWP mass
concentration in soil or sediment in units of μg/g. The formula for the calculation of target and sample TRWP
detection limits is specified in Annex DAnnex D.

11.3 Quantity of tyre polymer in the sample
The mass of polymer in the sample referenced to the SBR or IR standards shall be calculated by instrument
software using the calibration curve and the ratio of instrument response for the target compound to that of
deuterated internal standards spiked into the sample. Peak areas shall be individually inspected for quality
control.
The mass of tyre polymer in the sample is initially expressed as SBR and IR based on the use of these polymers
in the preparation of the calibration curve. The mass expressed as SBR is converted to a tyre polymer basis as
SBR/BR using the market share average styrene content in tread SBR/BR, as compared to the styrene content
in calibration SBR. The mass expressed as IR polymer mass is taken to represent NR mass from tyre polymer.
The formula and parameter values for calculating the amount of SBR/BR tyre polymer in the sample (μg) from
the instrument determined polymer mass expressed as IR and SBR are specified in Annex EAnnex E.

11.4 Mass concentration of TRWP
To express the result on the basis of TRWP, the polymer mass quantified by GC/MS shall be adjusted to account
for the:
a) a) representative SBR+BR 1,4-butadiene content (VCH marker);
b) b) market representative SBR styrene content (PCH marker) if PCH marker is used in analysis;
c) c) mineral encrustation composition of TRWP, and
d) d) dry mass of the sample analysed.
ISO/FDIS 21396:2026(en)
The TRWP concentration in soil or sediment shall be expressed in units of mass concentration (μg/g)
calculated using the formula and parameter values shown in E.5E.5.
12 Performance characteristics
12.1 General
The instruments used in this procedure shall be operated in accordance with the manufacturer’s instructions.
The analytical method shall be performed under a continuous quality control programme. The quality control
programme should employ the use of standard samples and blank samples.
12.2 Specific performance characteristics
A midpoint calibration curve check shall be analysed before and after each analysis series to verify recovery
within 80 % to 120 % of the known polymer spike amount.
The target spike recovery range for matrix spike analyses is 80 % to 120 %.
Corrective action when recovery is outside the specified range includes instrument maintenance, and
preparation of fresh calibration curves with existing calibration solution shall be implemented if the percent
drift exceeds 20 %.
13 Test report
The test report shall include at least the following information:
a) a) dated reference to this document;
b) b) identification of the client;
c) c) identification of the sample;
d) d) date and time of sampling, and necessary sampling data;
e) e) date and time of analysis;
f) f) identity of the analyst;
g) g) any procedure not specified in this document, or regarded as optional;
h) h) equipment and experimental conditions including GC/MS and pyrolys
...

PROJET FINAL
Norme
internationale
ISO/FDIS 21396
ISO/TC 45
Caoutchouc — Détermination
Secrétariat: DSM
de la concentration massique
Début de vote:
en particules d'usure des
2026-06-22
pneumatiques et de la route
Vote clos le:
(TWRP) dans le sol et les sédiments
2026-08-17
— Méthode par pyrolyse-GC/MS
Rubber — Determination of the mass concentration of tyre and
road wear particles (TRWP) in soil and sediment — Pyrolysis-gas
chromatography/mass spectrometry (GC/MS) method
LES DESTINATAIRES DU PRÉSENT PROJET SONT
INVITÉS À PRÉSENTER, AVEC LEURS OBSERVATIONS,
NOTIFICATION DES DROITS DE PROPRIÉTÉ DONT ILS
AURAIENT ÉVENTUELLEMENT CONNAISSANCE ET À
FOURNIR UNE DOCUMENTATION EXPLICATIVE.
OUTRE LE FAIT D’ÊTRE EXAMINÉS POUR
ÉTABLIR S’ILS SONT ACCEPTABLES À DES FINS
INDUSTRIELLES, TECHNOLOGIQUES ET COM-MERCIALES,
AINSI QUE DU POINT DE VUE DES UTILISATEURS, LES
PROJETS DE NORMES
INTERNATIONALES DOIVENT PARFOIS ÊTRE CONSIDÉRÉS
DU POINT DE VUE DE LEUR POSSI BILITÉ DE DEVENIR DES
NORMES POUVANT
SERVIR DE RÉFÉRENCE DANS LA RÉGLEMENTATION
NATIONALE.
Numéro de référence
ISO/FDIS 21396:2026(fr) © ISO 2026

PROJET FINAL
ISO/FDIS 21396:2026(fr)
Norme
internationale
ISO/FDIS 21396
ISO/TC 45
Caoutchouc — Détermination
Secrétariat: DSM
de la concentration massique
Début de vote:
en particules d'usure des
2026-06-22
pneumatiques et de la route
Vote clos le:
(TWRP) dans le sol et les sédiments
2026-08-17
— Méthode par pyrolyse-GC/MS
Rubber — Determination of the mass concentration of tyre and
road wear particles (TRWP) in soil and sediment — Pyrolysis-gas
chromatography/mass spectrometry (GC/MS) method
LES DESTINATAIRES DU PRÉSENT PROJET SONT
INVITÉS À PRÉSENTER, AVEC LEURS OBSERVATIONS,
NOTIFICATION DES DROITS DE PROPRIÉTÉ DONT ILS
AURAIENT ÉVENTUELLEMENT CONNAISSANCE ET À
FOURNIR UNE DOCUMENTATION EXPLICATIVE.
DOCUMENT PROTÉGÉ PAR COPYRIGHT
OUTRE LE FAIT D’ÊTRE EXAMINÉS POUR
ÉTABLIR S’ILS SONT ACCEPTABLES À DES FINS
© ISO 2026 INDUSTRIELLES, TECHNOLOGIQUES ET COM-MERCIALES,
AINSI QUE DU POINT DE VUE DES UTILISATEURS, LES
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
PROJETS DE NORMES
INTERNATIONALES DOIVENT PARFOIS ÊTRE CONSIDÉRÉS
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
DU POINT DE VUE DE LEUR POSSI BILITÉ DE DEVENIR DES
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
NORMES POUVANT
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
SERVIR DE RÉFÉRENCE DANS LA RÉGLEMENTATION
NATIONALE.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Genève
Tél.: [phone]
E-mail: [e-mail]
Web: www.iso.org
Publié en Suisse Numéro de référence
ISO/FDIS 21396:2026(fr) © ISO 2026

ii
ISO/FDIS 21396:2026(fr)
Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Principe. 2
5 Réactifs et matériels . 3
6 Appareillage . 3
7 Laboratoire de préparation des échantillons . 5
8 Gamme de mesure . 5
9 Limite de détection . 6
10 Mode opératoire . 6
10.1 Généralités .6
10.2 Collecte d'échantillons .6
10.3 Préparation de l'étalon interne deutéré .7
10.4 Préparation de la courbe d'étalonnage .7
10.4.1 Solutions mères .7
10.4.2 Courbe d'étalonnage . .8
10.5 Préparation de l'échantillon .9
10.5.1 Généralités .9
10.5.2 Séchage à l'étuve .9
10.5.3 Tamisage et homogénéisation .9
10.5.4 Prétraitement de l'échantillon .9
10.6 Mesurage de l'échantillon .10
10.6.1 Masse de l'échantillon .10
10.6.2 Ajout de l'étalon interne .10
10.6.3 Mesurage par pyrolyse-GC-MS .10
11 Analyse .11
11.1 Généralités .11
11.2 Limite de détection des TRWP (LOD) .11
11.3 Quantité de polymère de pneumatique dans l'échantillon .11
11.4 Concentration massique de TRWP dans l'échantillon . 12
12 Caractéristiques de performance .12
12.1 Généralités . 12
12.2 Caractéristiques de performance spécifiques . 12
13 Rapport d'essai .12
Annexe A (informative) Recette pour les courbes d’étalonnage et les solutions mères . 14
Annexe B (informative) Conditions instrumentales .16
Annexe C (informative) Courbes d’étalonnage représentatives et pyrogrammes d'ions totaux .18
Annexe D (informative) Calcul des limites de détection des TRWP .23
Annexe E (normative) Calcul des résultats à l’aide de marqueurs dimériques .25
Annexe F (informative) Fidélité .30
Bibliographie .31

iii
ISO/FDIS 21396:2026(fr)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux
de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général
confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire
partie du comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (IEC) en ce qui concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document a
été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir
www.iso.org/directives).
L’ISO attire l’attention sur le fait que la mise en application du présent document peut entraîner l’utilisation
d’un ou de plusieurs brevets. L’ISO ne prend pas position quant à la preuve, à la validité et à l’applicabilité de
tout droit de brevet revendiqué à cet égard. À la date de publication du présent document, l’ISO n'avait pas
reçu notification qu’un ou plusieurs brevets pouvaient être nécessaires à sa mise en application. Toutefois,
il y a lieu d’avertir les responsables de la mise en application du présent document que des informations
plus récentes sont susceptibles de figurer dans la base de données de brevets, disponible à l'adresse
www.iso.org/brevets. L’ISO ne saurait être tenue pour responsable de ne pas avoir identifié tout ou partie de
tels droits de propriété.
Les appellations commerciales éventuellement mentionnées dans le présent document sont données pour
information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion de
l'ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles techniques au
commerce (OTC), voir www.iso.org/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 45 Élastomères et produits à base
d'élastomères.
Cette deuxième édition annule et remplace la première édition (ISO/TS 21396:2017), qui a fait l’objet d’une
révision technique.
Les principales modifications sont les suivantes:
— ajout d’informations relatives aux conditions d’instrumentation pour le pyrolyseur à microfourneau et le
pyrolyseur résistif au 6.2.5.1;
— ajout de recommandations concernant le prétraitement chimique des échantillons au 10.5.4;
— révision de la méthode de calcul pour tenir compte des différences de microstructure de l’élastomère
entre les étalons d’étalonnage et la bande de roulement moyenne disponible sur le marché;
— ajout du marqueur 4-phénylcyclohexène dans les Articles 4, 8, 10.1, 10.3, 10.4.2, 10.6.3.4, 11.1 et 11.4,
ainsi que dans les Annexes C, D et E.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes se
trouve à l’adresse www.iso.org/fr/members.html.

iv
ISO/FDIS 21396:2026(fr)
Introduction
Les particules d'usure des pneumatiques et de la route (TRWP) sont générées par l’abrasion des bandes
de roulement de pneumatiques par la surface de la chaussée, et la libération subséquente de particules
dans l'environnement. Les TRWP se composent de particules de bandes de roulement de pneumatiques
[1]
incluant des matériaux provenant de la surface des revêtements routiers (Kreider et al. 2010 ). La fraction
d’élastomères dans les TRWP présentes dans les sols ou les sédiments est quantifiée, dans le présent
document, par pyrolyse-GC-MS directe (chromatographie en phase gazeuse/spectrométrie de masse). La
concentration massique peut être exprimée sur la base du polymère caoutchouc, de la bande de roulement de
pneumatique, ou de TRWP. Cette méthode a été utilisée pour mesurer la concentration dans les échantillons
[2] [3] [4]
de sols et sédiments (Unice et al. 2012 ; Unice et al. 2013 ; Barber et al. 2023 ). La concentration de
TRWP dans les fractions de PM et PM aéroportée est déterminée par une méthode similaire (Panko et
2.5 10
[5] [6]
al. 2013 ; Panko et al. 2019 ).
Des marqueurs chimiques spécifiques sont générés par pyrolyse de TRWP intactes présentes dans un
échantillon. Les marqueurs chimiques sont des fragments dimérique caractéristiques et spécifiques obtenus
par pyrolyse de polymères constituant les bandes de roulement des pneumatiques de véhicule de tourisme et
de poids lourds, incluant le caoutchouc butadiène, le caoutchouc styrène-butadiène et le caoutchouc isoprène.
Les fragments de polymères générés par pyrolyse des échantillons sont ensuite séparés par chromatographie
en phase gazeuse (GC) et identifiés par spectrométrie de masse (MS). La concentration massique des TRWP
est calculée à l’aide d’un taux moyen des polymères de bandes de roulement de pneumatiques utilisés sur
le marché et en utilisant la teneur en minéraux contenus dans les TRWP préalablement caractérisée. La
spécificité quant aux polymères de caoutchouc est assurée par quantification de fragments dimériques
[7] [8]
composés de deux unités monomères (Kitamura et al. 2007 ; Harada et al. 2009 ). La répétabilité est
assurée par l’utilisation d’un étalon interne deutéré présentant une structure polymérique similaire à celle
des polymères de bandes de roulement de pneumatiques. L’étalon interne permet de corriger la variabilité
du rendement de génération des analytes induite par les effets de matrice et la variabilité temporelle de la
réponse instrumentale. La méthode convient pour surveiller les variations de concentrations en TRWP dans
les sols et sédiments au cours du temps.
NOTE Les particules d’usure de pneumatiques et de la route sont une masse discrète de particules allongées
générées à l'interface de frottement entre le pneumatique et la surface de la route pendant la durée de vie d'un
pneumatique. Ces particules sont constituées de bande de roulement de pneumatique avec des inclusions minérales
provenant de la surface de la route.

v
PROJET FINAL Norme internationale ISO/FDIS 21396:2026(fr)
Caoutchouc — Détermination de la concentration massique
en particules d'usure des pneumatiques et de la route
(TWRP) dans le sol et les sédiments — Méthode par pyrolyse-
GC/MS
AVERTISSEMENT 1 — Il convient que l’utilisateur du présent document connaisse bien les pratiques
courantes de laboratoire. Le présent document n’a pas pour but de traiter tous les problèmes de
sécurité qui sont, le cas échéant, liés à son utilisation. Il incombe à l’utilisateur d’établir des pratiques
appropriées en matière d’hygiène et de sécurité.
AVERTISSEMENT 2 — Certains modes opératoires spécifiés dans le présent document peuvent
impliquer l’utilisation, ou la génération de déchets pouvant représenter un danger environnemental
local. Il convient de se référer à la documentation appropriée concernant leur manipulation et leur
élimination en toute sécurité après usage.
1 Domaine d’application
Le présent document spécifie une méthode de détermination de la concentration massique (μg/g) des
particules d’usure des pneumatiques et de la route (TRWP) dans des échantillons environnementaux de sol
ou de sédiments.
Le présent document établit les principes pour la collecte d'échantillons de sol ou de sédiments, la génération
de fragments pyrolytiques à partir de l'échantillon, et la quantification des fragments de polymères.
Le présent document est applicable aux échantillons environnementaux provenant du sol ou des sédiments.
Le présent document n’est pas applicable aux échantillons environnementaux provenant de l’air ambiant et
des eaux ambiantes.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu’ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l’édition citée s’applique. Pour
les références non datées, la dernière édition du document de référence s'applique (y compris les éventuels
amendements).
ISO 17257, Caoutchouc — Identification des polymères — Méthode par pyrolyse et chromatographie en phase
gazeuse avec détection par spectrométrie de masse
ISO 3310-1, Tamis de contrôle — Exigences techniques et vérifications — Partie 1: Tamis de contrôle en tissus
métalliques
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en normalisation,
consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l’adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l’adresse https:// www .electropedia .org/

ISO/FDIS 21396:2026(fr)
3.1
étalon interne deutéré
polymère à base de monomère contenant au moins une molécule de deutérium ajouté à un échantillon
en quantité fixe presque identique à l'analyte cible, utilisé pour corriger la dérive de l'instrument et
l'interférence de la matrice
3.2
masse sèche
masse de solides séchée dans une étuve pendant une durée et une température déterminée
3.3
masse humide
masse du solide avant séchage en étuve
3.4
contrôle
mesure répétée pour suivre les variations au cours d'une période donnée
3.5
pourcentage de masse sèche
masse sèche (3.2) des solides de l'échantillon exprimée en pourcentage de la masse humide (3.3) de
l'échantillon
3.6
analyse par pyrolyse
décomposition de molécules de polymères organiques en fragments caractéristiques séparés par (GC) et
quantifiés par (MS)
4 Principe
Le polymère de la bande de roulement des pneumatiques est quantifié en utilisant une calibration avec
standard interne et l'aire de pic des ions caractéristiques des fragments dimériques du polymère brut par
pyrolyse-GC-MS. Les produits de décomposition thermique des polymères réticulés à base de caoutchouc
1)
naturel (NR) (CAS Registry Number® 9006-04-6), de caoutchouc styrène-butadiène (SBR) (CAS RN® 9003-
55-8) et de caoutchouc butadiène (BR) (CAS RN® 9003-17-2), dépendent de l’abondance des polymères dans
l’échantillon. La pyrolyse du SBR génère du butadiène (CAS RN® 106-99-0), du 4-Vinylcyclohexène (dimère
de butadiène¸ VHC) (CAS RN® 4994-16-5), du styrène (CAS RN® 100-42-5), et du 4-phénylcyclohexène
(PCH) (CAS RN® 4994-16-5), tandis que la pyrolyse du BR génère uniquement un monomère de butadiène
[9]
et du VHC (Miller et al. 2022 ). Le NR est associé à un monomère d’isoprène (CAS RN® 78-79-5) et au
dipentène (dimère d’isoprène, DP) (CAS RN® 138-86-3). La quantification de la fraction synthétique (SBR
et BR) par le marqueur VCH est préférée en raison d’un facteur de réponse et d’une contribution supérieure
par rapport au marqueur PCH ne permettant d’estimer la fraction de polymère synthétique que sur une base
[11]
SBR. (Miller et al. 2022 ).
Les fragments dimériques présentent une bonne spécificité pour les polymères de caoutchouc, alors que les
substances organiques aussi bien anthropiques que naturelles sont des sources de marqueurs monomériques
[7]
(Kitamura 2007 ). Par conséquent, les marqueurs pyrolytiques monomériques sont sujets aux interférences
provenant de sources environnementales autres que les TRWP et ne conviennent pas pour la quantification
de la concentration en masse de TRWP dans le sol ou les sédiments. Un exemple bien connu est le styrène,
généré indifféremment par pyrolyse de caoutchouc SBR et de particules de gaz d’échappement de moteurs
[10]
diesels (Pierson and Brachaczek 1974 ). Les polymères utilisés dans la fabrication de pneumatiques et
leurs fragments pyrolytiques dimériques associés pour la quantification des TRWP sont indiqués dans le
Tableau 1.
1) « CAS Registry Number® » est une marque déposée de l’American Chemical Society (ACS). Cette information est
fournie pour la commodité des utilisateurs du présent document et ne constitue pas une approbation par l’ISO du produit
mentionné. Des produits équivalents peuvent être utilisés s’il est démontré qu’ils conduisent aux mêmes résultats.

ISO/FDIS 21396:2026(fr)
Tableau 1 — Fragments pyrolytiques dimériques des polymères caoutchouc utilisés dans les
pneumatiques
Formule du polymère Dimère
5 Réactifs et matériels
Utiliser uniquement des réactifs de qualité analytique reconnue.
5.1 Chloroforme, de qualité analytique. (non-deutéré CAS RN® 67-66-3 ou deutéré CAS RN® 865-49-6)
5.2 Hélium, d'une pureté de 99,999 5 % par volume. (CAS RN® 7440-59-7)
5.3 Hydroxyde de potassium à 10 % (100 g/l), de pureté > 86 % par volume. (CAS RN® 1310-58-3)
5.4 Eau purifiée, ultrapure de Type I.
5.5 Poly(1,4-isoprène) deutéré (d-IR), pour étalonnage interne.
5.6 Polystyrène polybutadiène deutéré (d-PSPB), pour étalonnage interne.
5.7 Caoutchouc poly(1,4-isoprène) (IR) (CAS RN® 9003-31-0), pour polymère de calibration.
5.8 Caoutchouc styrène-butadiène (SBR), pour polymère de calibration.
6 Appareillage
6.1 Échantillonnage du sol ou des sédiments — Équipement et consommables.
6.1.1 Dispositif d'échantillonnage.
Le dispositif d'échantillonnage doit être adapté à la collecte d'échantillons de sol ou de sédiments Les
dispositifs appropriés comprennent des truelles manuelles en acier inoxydable pré-nettoyées, des outils de
carottage ou des dispositifs de dragage à benne preneuse. Le prélèvement d'un échantillon de sédiments à
l'aide d'une drague à benne preneuse est illustré à la Figure 1.

ISO/FDIS 21396:2026(fr)
Figure 1 — Prélèvement d'échantillon à l'aide d'un dispositif de drague à benne preneuse
6.1.2 Conteneurs d'échantillons.
Les échantillons sont collectés dans des récipients propres fournis par le laboratoire, ou dans des récipients
propres manipulés conformément aux modes opératoires normalisés du laboratoire. La Figure 2 illustre la
mise en place d'un échantillon de sol dans un récipient à l'aide d'une truelle.
Figure 2 — Mise en place de l'échantillon dans le récipient à l'aide d'une truelle
6.2 Equipement pour analyse.
6.2.1 Étuve de laboratoire, pour le séchage des échantillons prélevés sur le terrain dans un récipient
propre fourni par le laboratoire.
6.2.2 Tamis, pour éliminer les gros agrégats qui ne conviennent pas à l'unité de pyrolyse. L'ouverture
nominale pour le tamisage à sec est de 1 mm, conformément à l'ISO 3310-1.
6.2.3 Balance de précision, pour la détermination de la masse d'échantillon tel qu'il a été prélevé, après
séchage au four, et après tamisage à sec. La balance doit être précise à 0,1 mg près et être entretenue,
étalonnée, et certifiée conformément aux recommandations du fabricant.

ISO/FDIS 21396:2026(fr)
6.2.4 Balance analytique, pour peser l'échantillon, l'étalon interne et le polymère de calibration utilisé
pour le mesurage. La balance doit être précise à au moins 0,01 mg près et être entretenue, étalonnée, et
certifiée conformément aux recommandations du fabricant.
6.2.5 Equipement de pyrolyse et chromatographie en phase gazeuse avec détection par
spectrométrie de masse, conforme aux spécifications de l'ISO 17257.
a) système de pyrolyse.
b) chromatographe en phase gazeuse équipé d'une colonne chromatographique.
c) détecteur de masse en mode impact électronique.
6.2.5.1 Un système de pyrolyse, avec un porte-échantillon à usage unique ou réutilisable devant être
choisi conformément aux recommandations du fabricant. Des exemples de systèmes pyrolytiques courants
associés à un chromatographe en phase gazeuse/spectromètre de masse sont présentés dans l'ISO 17257
comprenant des pyrolyseur à micro four avec un tube quartz et à point de Curie avec porte-échantillon. Les
pyrolyseur à filament de platine (résistif) ne doivent pas être utilisés pour la pyrolyse quantitative, car ils ne
[9]
satisfont pas aux exigences de la présente méthode. (Miller et al. 2022 ).
6.2.5.2 Chromatographe en phase gazeuse équipé d'une colonne, maintenu conformément aux
instructions du fabricant dont la colonne présente les caractéristiques spécifiées ci-dessous:
— longueur de la colonne: 25 m à 60 m;
— diamètre de la colonne: 0,25 mm à 0,35 mm;
— phase stationnaire de la colonne: 5 % diphényl-, 95 % polydiméthylsiloxane;
— épaisseur du film de la colonne: 0,20 µm to 1,0 µm.
6.2.5.3 Spectromètre de masse, entretenu conformément aux instructions du fabricant. Incluant, par
exemple, spectromètre de masse quadripolaire, spectromètre de masse à secteur magnétique ou tout autre
type d'instrument approprié équipé d’une source d'ionisation par impact électronique.
7 Laboratoire de préparation des échantillons
Les laboratoires de préparation des échantillons et les conteneurs d'échantillons choisis pour l'analyse
doivent être suffisamment exempts de contamination pour que les analyses à blanc démontrent l'absence
de polymère. Au moins une analyse à blanc doit être réalisée pour chaque type de récipient utilisé pour le
prélèvement de l'échantillon, et à la suite de modifications apportées aux modes opératoires normalisés ou à
l'équipement du laboratoire.
8 Gamme de mesure
La gamme de masse de polymère SBR/BR pouvant être quantifiée dans un sol ou des sédiments est
comprise entre 0,1 μg et 150 μg environ et entre 0,1 µg et 75 µg pour le polymère NR. En supposant une
masse d'échantillon totale de 0,020 g, cette gamme de masses correspond à une gamme de concentrations
en TRWP dans le sol et les sédiments comprise de 30 μg/g à 30 000 μg/g environ à l'aide des marqueurs VHC
et DP ou alternativement de 60 μg/g à 75 000 μg/g en utilisant les marqueurs PCH et DP. L’écart-type relatif

ISO/FDIS 21396:2026(fr)
des concentrations obtenues sur des échantillons en double est d’environ 30 % pour des échantillons de
[12]
10,0 g à 50,0 g homogénéisés au mortier et au pilon .
NOTE La détermination de la gamme de concentration de TRWP est basée sur la Formule (D.2). Par exemple, la limite
inférieure de la gamme de concentration de TRWP est (0,1 μg × 0,36 ÷ 0,70 + 0,1 μg) ÷ 0,5 ÷ 0,5 ÷ 0,020 g = 30 μg/g.
Le premier facteur de 0,36 ÷ 0,70 tient compte de la différence entre la teneur totale en 1,4-butadiène dans le SBR
d'étalonnage et la moyenne SBR/BR du marché. Le second facteur de 0,5 tient compte de la fraction de polymère dans
la bande de roulement des pneumatiques. Les TRWP sont constituées de bandes de roulement enrichies d'incrustations
minérales provenant de la surface de la chaussée. Le troisième facteur de 0,5 tient compte de la fraction de bande de
roulement dans les TRWP.
9 Limite de détection
La limite de détection (LOD) des TRWP dépend de la masse de l'échantillon pyrolysé, de la sensibilité de
l'équipement utilisé, et des niveaux de blancs réalisés par le laboratoire. Dans la pratique, les contraintes
d'échantillonnage et la capacité de l'unité de pyrolyse déterminent la LOD la plus basse possible. Pour une
masse nominale d'échantillon de 0,020 0 g, une LOD d'environ 30 μg/g de TRWP dans le sol ou les sédiments
[2]
a été rapportée (Unice et al. 2012 ).
10 Mode opératoire
10.1 Généralités
La méthode est définie pour un échantillon de sol ou de sédiment séché en étuve et compatible avec l'unité
de pyrolyse. Pour décomposer l’échantillon l'énergie thermique est appliquée à un échantillon au sein d’un
pyrolyseur en l'absence d'oxygène. Les réactions secondaires sont minimisées par le chauffage rapide du
pyrolyseur à la température cible. La masse nominale de l'échantillon pour l'exemple d'unité de pyrolyse
décrite en Annexe B est de 0,020 0 g. Le mode opératoire de collecte des échantillons et de pyrolyse-GC-MS
en laboratoire comprend les six étapes suivantes, décrites respectivement de 10.2 à 10.6:
a) collecte d'échantillons;
b) préparation de l'étalon interne deutéré;
c) préparation de la courbe d'étalonnage;
d) préparation de l'échantillon;
e) pyrolyse des échantillons avec décomposition des polymères dans des conditions thermiques définies;
f) mesurage des dimères par séparation chromatographique en phase gazeuse et spectrométrie de masse.
Le mode opératoire fait appel à des étalons polymères deutérés en qualité d’étalons internes afin
d’augmenter la justesse et l'exactitude de la mesure de concentration de TRWP. L'étalon interne est utilisé
pour corriger les effets de matrice qui affectent la pyrolyse du polymère et la récupération des fragments.
L'étalon interne corrige également les variations de l'état de la source d'ionisation du spectromètre de masse
et les fluctuations des débits de gaz vecteur. Les étalons internes sont le polyisoprène deutéré (d-IR) et le
polystyrène polybutadiène deutéré (d-PSPB), qui sont des polymères marqués avec l'isotope mineur stable
de l'hydrogène, le deutérium. Les produits de décomposition thermique du d-IR et du d-PSPB obtenus par
pyrolyse-GC-MS peuvent être distingué des marqueurs DP, VCH et PCH associés respectivement au NR, au
SBR/BR et au SBR, sur la base de leurs temps de rétention et de leurs rapport masse/charge.
10.2 Collecte d'échantillons
Un échantillon de sol ou de sédiments est collecté dans des récipients d'échantillonnage propres fournis
ou approuvés par le laboratoire. L'échantillon doit être prélevé à l'aide d'un dispositif propre adapté au
prélèvement d'échantillons de sol ou de sédiments, comme décrit au 6.1.1. Le mode opératoire normalisé pour
le prélèvement de l'échantillon doit être approuvé par le laboratoire. Un formulaire de chaîne de traçabilité

ISO/FDIS 21396:2026(fr)
documentant le prélèvement et la remise de l'échantillon doit être conservé. Il convient de prélever une
masse de sol ou de sédiments d'au moins 10,0 g à 50,0 g pour garantir une homogénéisation adéquate.
10.3 Préparation de l'étalon interne deutéré
Les étalons deutérés d-IR et d-PSPB, de pureté connue, doivent être obtenus avant l’analyse (voir Tableau 2).
Leur pureté doit être suffisamment élevée pour éviter toute interférence avec les concentrations en TRWP
égales ou supérieures à la limite de détection ou à la limite significative de l’analyse.
Une recette pour la préparation de la solution mère d’étalon interne pouvant être utilisée est décrite
dans l'Annexe A. D’autres recettes peuvent être utilisées pour atteindre les objectifs de l’analyse. Pour
préparer les solutions mères, un polymère brut d-IR ou d-PSPB est pesé puis placé dans une fiole jaugée.
Du chloroforme doit être versé jusqu’aux deux-tiers du volume total spécifié dans la recette. La dissolution
des étalons deutérés peut être réalisée par divers moyens, à condition que le laboratoire vérifie que l’étalon
est complètement dissous et que la solution est homogène. Immédiatement avant l’analyse, du chloroforme
doit être ajouté afin d’atteindre le volume total spécifié dans la méthode, puis la solution doit être agitée
pour assurer son homogénéité. Immédiatement avant l’Les polymères bruts doivent être dissous dans le
chloroforme avant le jour de l’analyse afin de garantir un temps de dissolution suffisant ou par dissolution
assistée mécaniquement, par exemple par agitation orbitale ou par agitation magnétique.analyse, du
chloroforme doit être ajouté afin d’atteindre le volume total spécifié dans la méthode, puis la solution doit
être agitée pour assurer son homogénéité. Le laboratoire doit vérifier que l’étalon est complètement dissous
et que la solution est homogène. Le chloroforme deutéré peut être utilisé comme solvant afin de réduire la
possibilité d’échange entre l’hydrogène et le deutérium.
Tableau 2 — Polymères, marqueurs et étalons internes pour analyse par pyrolyse-GC-MS
Polymère de pneumatique
Attribut
SBR
NR SBR, BR
(Alternatif pour SBR, BR)
Marqueur pyrolytique DP VCH PCH
Temps de rétention du mar-
~17 ~10 ~23
a
queur pyrolytique (min)
m/z cible 68 54 104
b
m/z validation 136 108 158
Poly([styrène deutéré-d8]-
Poly(1,4-isoprène-
Étalon interne CO-[butadiène deuté- [d-PSPB]
d8) [d-IR] deutéré
ré = d6], aléatoire [d-PSPB]
m/z cible de l'étalon interne 76 60 112
Caoutchouc poly(1,4-
Polymère de calibration SBR SBR
isoprène) (IR)
Points de calibration (μg) 1; 5; 10; 25; 75 2; 10; 20; 50; 150 2; 10; 20; 50; 150
a
Les temps de rétention sont approximatifs et obtenu avec les conditions de l'exemple en l'Annexe B. Ils peuvent varier en
fonction des conditions du laboratoire, de la configuration de l’instrument, des dimensions de la colonne et du programme de
température.
b
L’absence de co-élution d’interférant avec chaque marqueur et étalon doit être vérifiée lors du choix des marqueurs et du
protocole de prétraitement pour la quantification.
c
D'autres points d'étalonnage peuvent être utilisés pour atteindre les objectifs de l'analyse.
10.4 Préparation de la courbe d'étalonnage
10.4.1 Solutions mères
Des solutions mères de polymères bruts dans du chloroforme, comprenant du caoutchouc poly(1,4-
isoprène) synthétique (IR) et du SBR, doivent être préparées pour établir des courbes d’étalonnage. Des
polymères d’étalonnage dont la microstructure est connue ou déterminable doivent être sélectionnés, car
la microstructure influence le résultat de la courbe d’étalonnage. Des SBR disponibles dans le commerce,

ISO/FDIS 21396:2026(fr)
tels que le grade SBR 1500, peuvent être employés comme polymère de calibration. Il est également possible
d'utiliser des copolymères polystyrène-polybutadiène (PSPB). Une recette pour la préparation de solutions
mères d’étalons internes qu’il convient d’utiliser est décrite dans l'Annexe A. D’autres recettes peuvent être
utilisées pour atteindre les objectifs de l’analyse. Pour préparer les solutions mères, un polymère brut IR ou
SBR est pesé et placé dans une fiole jaugée. Du chloroforme doit être ajouté jusqu’aux deux-tiers du volume
total spécifié dans la recette. La dissolution du polymère peut être réalisée par divers moyens, à condition
que le laboratoire vérifie que le polymère est complètement dissous et que la solution est homogène.
Immédiatement avant l’analyse, du chloroforme est ajouté afin d’atteindre le volume total spécifié dans la
méthode, puis la solution est agitée suffisamment pour assurer son homogénéité. La solution de chloroforme
est introduite dans le porte-échantillon à l’aide d’une micropipette, puis évaporée à sec à température
ambiante pendant 30 min. Les polymères d’étalonnage doivent être conservés au frais et à l'abri de la lumière.
10.4.2 Courbe d'étalonnage
Une courbe d’étalonnage interne doit être préparée par régression des moindres carrés avec ajustement
quadratique selon les conditions de l’instrument décrites en 6.2 et dans l'Annexe B. Des polymères
synthétiques IR et SBR sont utilisés comme substitut de bande de roulement à base de NR et de SBR/BR
dans la préparation de la courbe d’étalonnage . Il convient que la masse de polymère analysée pour les
échantillons d’étalonnage soit comprise entre 1,00 μg et 75,0 μg pour l'IR et entre 2,00 μg et 150 μg pour
le SBR (voir Tableau 2). D’autres points d’étalonnage peuvent être utilisés pour atteindre les objectifs de
l’analyse. La limite inférieure d’étalonnage doit être égale à la limite de quantification (LOQ) définie pour la
méthode. Le rapport signal/bruit (S/N) de la limite de détection (LOD) doit être égal à trois et supérieur ou
égal à cinq pour limite de quantification (LOQ).
Les courbes d’étalonnage employant les étalons internes sont établies en traçant le ratio de réponse des aires
de pic en fonction du rapport de masses en utilisant une régression quadratique. Le facteur de réponse est
le rapport de l’aire de pic intégrée du marqueur de pyrolyse de l’étalon d’étalonnage à l’aire de pic intégrée
du marqueur de pyrolyse de l’étalon interne. Le rapport de masses est le rapport de la masse de la solution
d’étalonnage à la masse d’étalon interne ajoutée.
Le critère d’acceptation des courbes d’étalonnage est un coefficient de détermination (r ) supérieur ou
égal à 0,99. Il convient d’utiliser le logiciel de l’instrument pour quantifier les aires de pics des marqueurs
pyrolytiques des étalons internes deutérés et des marqueurs pyrolytiques des étalons. Les aires de pics
doivent être examinées individuellement pour assurer le contrôle de la qualité. Les solutions mères
doivent être remplacées au plus tard trois mois après leur préparation initiale. Des étalons de vérification
d’étalonnage doivent être mis en place afin de contrôler la validité des courbes d’étalonnage initiales. Le
critère d’acceptation pour les courbes d’étalonnage doit être une dérive de moins de 20 % avant et après
chaque série d’analyses, déterminée à l'aide de la Formule (1):
 MM 
tc
d�� 100 (1)
 
M
 
t
où
d est la dérive (%);
M est la masse mesurée de l’étalon de vérification d’étalonnage en continu, déterminée à partir de
c
la solution d’étalonnage;
M est la masse théorique de l’étalon de vérification d’étalonnage en continu, telle que définie par
t
la solution d’étalonnage.
Des étalons de vérification frais doivent être préparés avant chaque séquence d’analyse ou lorsque la dérive
dépasse 20 %.
Des courbes d’étalonnage et des pyrogrammes sont présentés dans l’Annexe C. Il convient de préparer des
courbes d'étalonnage SBR pour les marqueurs VCH et PCH. La quantification de la fraction synthétique (SBR
et BR) par le marqueur VCH est à préférer, comme expliqué à l'Article 4, Principes. Le marqueur PCH peut
être utilisé comme marqueur de diagnostic ou de quantification secondaire.

ISO/FDIS 21396:2026(fr)
10.5 Préparation de l'échantillon
10.5.1 Généralités
Les échantillons doivent être préparés pour l'analyse par pyrolyse dans un environnement exempt de toute
contamination polymérique. Les échantillons ne doivent pas être préparés pour l'analyse tant que des
analyses de blancs acceptables ne sont pas obtenues.
10.5.2 Séchage à l'étuve
L'échantillon de sol ou de sédiments doit être placé dans un récipient approprié et séché dans une étuve de
laboratoire pendant 24 h à 105 °C. Après séchage, l’échantillon doit être refroidi à température ambiante dans
un dessiccateur ou par tout autre moyen permettant d’obtenir des conditions d’humidité contrôlée avant la
pesée. La masse humide et la masse sèche de l’échantillon doivent être enregistrées, et le pourcentage de
masse sèche déterminé selon la Formule (2). La masse sèche doit être pesée après que la température de
l’échantillon séché a atteint la température ambiante.
M
d
P 100 (2)
dm
M
w
où
P est le pourcentage de masse sèche (%);
dm
M est la masse humide de l'échantillon (g);
w
M est la masse sèche de l'échantillon (g).
d
10.5.3 Tamisage et homogénéisation
Après séchage, il convient de tamiser l’échantillon pour éliminer les gros agrégats inadaptés au pyrolyseur.
L'ouverture nominale pour le tamisage à sec doit être de 1 mm comme spécifié dans l'ISO 3310-1. L’échantillon
tamisé (10 g à 50 g) doit être prémélangé afin de favoriser la distribution initiale des particules. Ensuite,
l’échantillon doit être homogénéisé à l’aide d’un mortier et d’un pilon propres, pendant une seule session
de 2 à 5 minutes, en appliquant une pression constante jusqu’à l’obtention d’une homogénéité visuelle. Un
broyage excessif doit être évité.
10.5.4 Prétraitement de l'échantillon
Le prétraitement de l’échantillon doit être effectué afin d’éliminer les interférences potentielles dues
[12]
à l’élution de composés organiques naturels et synthétiques (More et al. 2023 ). Une masse de 0,500 g
d’échantillon sec, tamisé et homogénéisé ainsi que 10 ml de solution aqueuse d’hydroxyde de potassium
décrite en 5.3 doivent être introduits dans un tube en polypropylène scellé et incubés à 60 °C pendant 24 h.
Après incubation, les échantillons doivent être recueillis sur un filtre à mem
...