SIST ISO 17735:2019

Workplace atmospheres - Determination of total isocyanate groups in air using 1-(9-anthracenylmethyl)piperazine (MAP) reagent and liquid chromatography

This document specifies a method for the sampling and analysis of airborne organic isocyanates in
workplace air.
This document is applicable to a wide range of organic compounds containing isocyanate groups,
including monofunctional isocyanates (e.g. phenyl isocyanate), diisocyanate monomers [e.g.
1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate
(MDI), and isophorone diisocyanate (IPDI)], prepolymers (e.g. the biuret and isocyanurate of HDI), as
well as chromatographable intermediate products formed during production or thermal breakdown of
polyurethane.
In mixed systems of HDI and IPDI products, it is impossible to identify and quantify low levels of IPDI
monomer using this document, due to coelution of IPDI monomer with HDI-uretidinedione.
It is known that the method underestimates the oligomer in MDI-based products. Total isocyanate
group (NCO) is underestimated in MDI-based products by about 35 % as compared to dibutylamine
titration.
The method has been successfully modified to be used with LC-MS-MS for TDI monomer using an
isocratic 70 % acetonitrile/30 % 10 mM ammonium formate mobile phase.
The useful range of the method, expressed in moles of isocyanate group per species per sample, is
approximately 1 × 10−10 to 2 × 10−7. The instrumental detection limit for the monomers using both
ultraviolet (UV) detection and fluorescence (FL) detection is about 2 ng monomer per sample. The
useful limit of detection for the method using reagent impregnated filters is about 10 ng to 20 ng
monomer per sample for both UV and FL detection. For a 15 l sample, this corresponds to 0,7 μg/m−3 to
1,4 μg/m−3. For impinger samples, which require solid phase extraction, experience has shown that the
useful limit of detection is about 30 ng to 80 ng monomer per sample.

Air des lieux de travail - Dosage des groupements isocyanates totaux dans l'air par réaction avec la 1-(9-anthracénylméthyl)pipérazine (MAP) et par chromatographie en phase liquide

Zrak na delovnem mestu - Določevanje skupin izocianatov v zraku z reagentom 1-(9-antracenilmetil)piperazin (MAP) in s tekočinsko kromatografijo

Ta dokument določa metodo za vzorčenje in analizo organskih izocianatnih spojin v
zraku na delovnem mestu.
Ta dokument se uporablja za širok nabor organskih spojin, ki vsebujejo skupine izocianatov, vključno z monofunkcijskimi izocianati (npr. fenil izocianat), monomeri diizocianata [npr.
1,6-heksametilen diizocianat (HDI), toluen diizocianat (TDI), difenilmetan-4,4’-diizocianat (MDI) in izoforon diizocianat (IPDI)], prepolimeri (npr. biuret in izocianurat HDI) ter za vmesne proizvode, ki so primerni za kromatografijo in oblikovani med proizvodnjo ali toplotno razgradnjo poliuretana.
V mešanih sistemih izdelkov HDI in IPDI je mogoče s tem dokumentom določiti in količinsko opredeliti nizke ravni monomera IPDI zaradi koelucije monomera IPDI z uretidindionom HDI. Znano je, da metoda podcenjuje oligomer v izdelkih iz MDI. Celotna skupina izocianatov (NCO) je v izdelkih iz MDI podcenjena za približno 35 % v primerjavi s titracijo
dibutilamina.
Metoda je bila uspešno prilagojena za določevanje monomera TDI z uporabo tekočinske kromatografije s tandemsko masno spektrometrijo (LC-MS-MS) pri
izokratski mobilni fazi, sestavljeni iz 70 % acetonitrila in 30 % amonijevega formata 10 mM.
Uporabno območje metode, izraženo v molih skupine izocianatov na zvrst na vzorec, je
približno 1 × 10−10 do 2 × 10−7. Meja detekcije instrumentov za monomere je pri
ultravijoličnem (UV) in fluorescentnem (FL) zaznavanju v obeh primerih približno 2 ng monomera na vzorec. Uporabna
meja zaznavanja za metodo z uporabo filtrov, prepojenih z reagenti, je približno od 10 ng do 20 ng monomera na vzorec za UV- in FL-zaznavanje. Pri 15-litrskem vzorcu to ustreza od 0,7 μg/m−3 do 1,4 μg/m−3. Pri vzorcih za kinetični vzorčevalnik, za katerega je potrebna ekstrakcija v trdni fazi, izkušnje kažejo, da je uporabna meja zaznavanja od približno 30 ng do 80 ng monomera na vzorec.

General Information

• Status: Published
• Public Enquiry End Date: 09-Oct-2018
• Publication Date: 18-Aug-2019
• ICS: 13.040.30 - Workplace atmospheres
• Technical Committee: KAZ - Air quality
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 12-Jun-2019
• Due Date: 17-Aug-2019
• Completion Date: 19-Aug-2019
• Ref Project: ISO 17735:2019 - Workplace atmospheres — Determination of total isocyanate groups in air using 1-(9-anthracenylmethyl)piperazine (MAP) reagent and liquid chromatography

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 17735
Second edition
2019-04
Workplace atmospheres —
Determination of total
isocyanate groups in air using
1-(9-anthracenylmethyl)piperazine
(MAP) reagent and liquid
chromatography
Air des lieux de travail — Dosage des groupements isocyanates totaux
dans l'air par réaction avec la 1-(9-anthracénylméthyl)pipérazine
(MAP) et par chromatographie en phase liquide
Reference number
ISO 17735:2019(E)
©
ISO 2019

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ISO 17735:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
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’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 17735:2019(E)

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
5.1 General . 3
5.2 MAP reagent . 4
5.3 Reagent solutions . 5
5.3.1 Impinger solution . . 5
5.3.2 Solution for filter impregnation . 6
5.3.3 Filter extraction solution . 6
5.3.4 Stability of reagent solutions . 6
5.4 Standard matching solutions . 6
5.4.1 General. 6
5.4.2 Preparation of monomer derivatives . 7
5.4.3 Preparation of standard solutions of monomer derivatives for HPLC analysis . 7
5.4.4 Preparation of monomer derivatives for solid-phase extraction (SPE) . 7
5.4.5 Preparation of derivative solutions of bulk isocyanate products . 8
5.5 HPLC mobile phase. 8
5.5.1 General. 8
5.5.2 Mobile phase buffer solutions . 8
5.5.3 Primary mobile phases . . 8
5.5.4 Post-column acid mobile phase . 9
6 Apparatus . 9
6.1 General . 9
6.2 Sampler . 9
6.2.1 General. 9
6.2.2 Filters . 9
6.2.3 Midget impingers . 9
6.3 Sampling pump .10
6.4 Tubing .10
6.5 Flowmeter .10
6.6 Filtration and solid-phase extraction equipment .10
6.7 Liquid chromatographic system .10
6.7.1 Autosampler .10
6.7.2 Pumping system .10
6.7.3 Analytical column .10
6.7.4 Column oven .11
6.7.5 Post-column acid delivery pump .11
6.7.6 Detectors .11
7 Air sampling .11
7.1 Pre-sampling laboratory preparation .11
7.1.1 Cleaning of sampling equipment .11
7.1.2 Preparation of MAP-coated filter samplers .11
7.1.3 Preparation of extraction solution jars.11
7.2 Pre-sampling field preparation .11
7.2.1 Calibration of pump .11
7.2.2 Preparation of samplers .12
7.3 Collection of air samples .12
7.3.1 Filter sampling .12
© ISO 2019 – All rights reserved iii

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ISO 17735:2019(E)

7.3.2 Impinger sampling .12
7.3.3 Sampling with an impinger followed by a filter .12
7.4 Blanks and negative controls .12
7.5 Bulk products .13
7.6 Shipment of samples .13
7.7 Filter test samples .13
7.8 Impinger test samples .13
8 HPLC analysis .14
8.1 Instrumental settings .14
8.2 HPLC programme.14
9 Data handling .15
9.1 Monomer measurement .15
9.2 Oligomer measurement (total detectable isocyanate) .16
10 Calibration and quality control .16
10.1 Standard matching solutions .16
10.2 Calibration curves .16
10.3 Blank tests .17
10.4 Bulk products .17
10.5 Quality control spikes .17
11 Calculations.17
11.1 Monomer .17
11.2 Oligomers (total detectable isocyanate) .18
12 Interferences .18
13 Determination of performance characteristics.19
13.1 General .19
13.2 Assessment of performance characteristics .20
13.2.1 Collection efficiency relative to particle size distribution.20
13.2.2 Air sampling .20
13.2.3 Analysis .21
13.2.4 Mass of compound in sample blank .25
13.2.5 Between-laboratory uncertainty contributions .26
13.2.6 Combined uncertainty .26
13.2.7 Expanded uncertainty .26
13.2.8 Uncertainty from performance criteria .26
Annex A (informative) Performance characteristics .27
Bibliography .29
iv © ISO 2019 – All rights reserved

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ISO 17735:2019(E)

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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 2,
Workplace atmospheres.
This second edition cancels and replaces the first edition (ISO 17735:2009), which has been technically
revised. The main changes compared to the previous edition are as follows.
— Additional limit of detection information has been provided (Clause 1).
— The method has been used in high air concentrations successfully with a higher reagent concentration
in an impinger (5.3.1).
— During processing of impinger samples, rinsing the SPE cartridge with 6 ml dichloromethane has
been changed to rinsing with two consecutive 3 ml aliquots. This is more effective in removing all
of the butyl benzoate impinger solvent (7.8).
— The liquid chromatographic system has been adapted to use a smaller diameter analytical column
(6.7.3).
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.
© ISO 2019 – All rights reserved v

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ISO 17735:2019(E)

Introduction
This document specifies the use of 1-(9-anthracenylmethyl)piperazine (MAP) to measure monomeric
and oligomeric isocyanate species in workplace atmospheres. MAP was designed to improve the
reliability of identification of isocyanate species in sample chromatograms and to improve the
accuracy of quantification of these species relative to established reagents. The high performance
liquid chromatography (HPLC) analysis uses a pH gradient to selectively accelerate the elution of
MAP derivatives of oligomeric isocyanates that might be unobservable in an isocratic analysis. The
[8]
performance of MAP has been compared to other reagents used for total isocyanate analysis , MAP has
been found to react with phenyl isocyanate (used as a model isocyanate) as fast as or faster than other
reagents commonly used for isocyanate analysis. The UV response of MAP derivatives is comparable
to that of 9-(methylaminomethyl)anthracene (MAMA) derivatives and considerably greater than other
commonly used reagents [approximately three times greater than 1-(2-methoxyphenyl)piperazine
(1-2MP) derivatives of aromatic isocyanates and 14 times greater than 1-2MP derivatives of aliphatic
isocyanates]. The compound-to-compound variability of UV response per isocyanate group for MAP
derivatives is smaller than the variability of any other commonly used reagent/detector combination
(the coefficient of variation is 3,5 % for five model isocyanates). This results in more accurate
quantification of detectable non-monomeric isocyanate species based on a calibration curve generated
from analysing standards of monomeric species. The monomeric species used for calibration is generally
the one associated with the product being analysed, but others could be used due to the very small
compound-to-compound response variability of the MAP derivatives. The intensity of fluorescence
response of MAP derivatives is comparable to that of MAMA derivatives and considerably greater
than other reagents (e.g. approximately 30 times more intense than that of tryptamine derivatives).
The compound-to-compound variability in fluorescence response has been found to be smaller than
that of MAMA derivatives but larger than that of tryptamine derivatives (MAMA = 59 % coefficient
of variation, MAP = 33 % coefficient of variation, and tryptamine = 16 % coefficient of variation for
5 model isocyanates). The compound-to-compound fluorescence variability of MAP derivatives is
considered too great for accurate quantification of non-monomeric isocyanate species based on
calibration with monomer standards. However, the sensitivity of the fluorescence detection makes
it especially suitable for quantification of low levels of monomer, and the selectivity is very useful to
designate an unidentified HPLC peak as a MAP derivative. MAP derivatives also give a strong response
by electrochemical detection. The pH gradient used in the HPLC analysis selectively accelerates the
elution of amines (MAP derivatives are amines) and is very strong (it accelerates MDI more than
100-fold). Re-equilibration to initial conditions is almost immediate. Many oligomeric species can be
measured in the 30 min MAP analysis that may be unobservable in a much longer isocratic analysis.
MAP has been used in several studies comparing it side-by-side with other methods. Reference [9]
found MAP impingers and NIOSH 5521 impingers (comparable to MDHS 25) to give comparable
results in spray painting environments. Reference [9] used MAP reagent, but the pH gradient was not
employed. Reference [10] compared MAP impingers with several other impinger methods (NIOSH 5521
and NIOSH 5522) and the double filter method. The average MAP oligomer value was substantially
higher than the other impinger methods and slightly higher than the double filter method. The pH
gradient was used in these MAP analyses. Reference [11] found that the MAP oligomer results compared
favourably against several other methods for measurement of oligomeric isocyanates in the collision
repair industry, and agreed well with the reference values.
[12]
The MAP method is currently available as NIOSH Method 5525 . The performance characteristics of
the method have been evaluated in Reference [13].
vi © ISO 2019 – All rights reserved

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INTERNATIONAL STANDARD ISO 17735:2019(E)
Workplace atmospheres — Determination of total
isocyanate groups in air using 1-(9-anthracenylmethyl)
piperazine (MAP) reagent and liquid chromatography
1 Scope
This document specifies a method for the sampling and analysis of airborne organic isocyanates in
workplace air.
This document is applicable to a wide range of organic compounds containing isocyanate groups,
including monofunctional isocyanates (e.g. phenyl isocyanate), diisocyanate monomers [e.g.
1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate
(MDI), and isophorone diisocyanate (IPDI)], prepolymers (e.g. the biuret and isocyanurate of HDI), as
well as chromatographable intermediate products formed during production or thermal breakdown of
polyurethane.
In mixed systems of HDI and IPDI products, it is impossible to identify and quantify low levels of IPDI
monomer using this document, due to coelution of IPDI monomer with HDI-uretidinedione.
It is known that the method underestimates the oligomer in MDI-based products. Total isocyanate
group (NCO) is underestimated in MDI-based products by about 35 % as compared to dibutylamine
titration.
The method has been successfully modified to be used with LC-MS-MS for TDI monomer using an
isocratic 70 % acetonitrile/30 % 10 mM ammonium formate mobile phase.
The useful range of the method, expressed in moles of isocyanate group per species per sample, is
−10 −7
approximately 1 × 10 to 2 × 10 . The instrumental detection limit for the monomers using both
ultraviolet (UV) detection and fluorescence (FL) detection is about 2 ng monomer per sample. The
useful limit of detection for the method using reagent impregnated filters is about 10 ng to 20 ng
−3
monomer per sample for both UV and FL detection. For a 15 l sample, this corresponds to 0,7 µg/m to
−3
1,4 µg/m . For impinger samples, which require solid phase extraction, experience has shown that the
useful limit of detection is about 30 ng to 80 ng monomer per sample.
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.
EN 1232, Workplace atmospheres — Pumps for personal sampling of chemical agents — Requirements and
test methods
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
© ISO 2019 – All rights reserved 1

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ISO 17735:2019(E)

4 Principle
A measured volume of air is drawn through either an impinger containing a solution of
1-(9-anthracenylmethyl)piperazine (MAP), a filter impregnated with MAP, or a sampling train
consisting of an impinger followed by an impregnated filter. The choice of sampler depends on the
chemical and physical characteristics of the airborne isocyanate[14]. If an impinger is used, the
solution is subjected to solid-phase extraction (SPE) and the eluate is concentrated and analysed by
reverse phase high performance liquid chromatography (HPLC) with ultraviolet (UV) absorbance
and fluorescence (FL) detection in series. If an impregnated filter is used for sampling, it is extracted
with solvent either in the field after completion of sampling or in the laboratory. Waiting to extract
the filter until after the sample has been received by the analytical laboratory is acceptable only for
analysis of isocyanates collected as vapour. This solution is filtered and analysed by HPLC/UV/FL.
Isocyanate-derived peaks are identified based on their UV and FL responses and by comparison with
the chromatogram of a derivatized bulk isocyanate product if available. Quantification of compounds
for which analytical standards are available (generally monomers) is achieved by comparison of the FL
peak height of the sample peak with the FL peak height of standard matching solutions. Quantification
of compounds for which analytical standards are not available is achieved by comparison of the UV
area of the sample peak with the UV area of the appropriate monomer standard (i.e. the monomer from
which the isocyanate product is derived).
Structures of some common diisocyanate monomers are shown in Figure 1.
2 © ISO 2019 – All ri
...

SLOVENSKI STANDARD
SIST ISO 17735:2019
01-september-2019
Zrak na delovnem mestu - Določevanje skupin izocianatov v zraku z reagentom 1-
(9-antracenilmetil)piperazin (MAP) in s tekočinsko kromatografijo
Workplace atmospheres - Determination of total isocyanate groups in air using 1-(9-
anthracenylmethyl)piperazine (MAP) reagent and liquid chromatography
Air des lieux de travail - Dosage des groupements isocyanates totaux dans l'air par
réaction avec la 1-(9-anthracénylméthyl)pipérazine (MAP) et par chromatographie en
phase liquide
Ta slovenski standard je istoveten z: ISO 17735:2019
ICS:
13.040.30 Kakovost zraka na delovnem Workplace atmospheres
mestu
SIST ISO 17735:2019 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 17735:2019

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SIST ISO 17735:2019
INTERNATIONAL ISO
STANDARD 17735
Second edition
2019-04
Workplace atmospheres —
Determination of total
isocyanate groups in air using
1-(9-anthracenylmethyl)piperazine
(MAP) reagent and liquid
chromatography
Air des lieux de travail — Dosage des groupements isocyanates totaux
dans l'air par réaction avec la 1-(9-anthracénylméthyl)pipérazine
(MAP) et par chromatographie en phase liquide
Reference number
ISO 17735:2019(E)
©
ISO 2019

---------------------- Page: 3 ----------------------

SIST ISO 17735:2019
ISO 17735:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
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’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

---------------------- Page: 4 ----------------------

SIST ISO 17735:2019
ISO 17735:2019(E)

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
5.1 General . 3
5.2 MAP reagent . 4
5.3 Reagent solutions . 5
5.3.1 Impinger solution . . 5
5.3.2 Solution for filter impregnation . 6
5.3.3 Filter extraction solution . 6
5.3.4 Stability of reagent solutions . 6
5.4 Standard matching solutions . 6
5.4.1 General. 6
5.4.2 Preparation of monomer derivatives . 7
5.4.3 Preparation of standard solutions of monomer derivatives for HPLC analysis . 7
5.4.4 Preparation of monomer derivatives for solid-phase extraction (SPE) . 7
5.4.5 Preparation of derivative solutions of bulk isocyanate products . 8
5.5 HPLC mobile phase. 8
5.5.1 General. 8
5.5.2 Mobile phase buffer solutions . 8
5.5.3 Primary mobile phases . . 8
5.5.4 Post-column acid mobile phase . 9
6 Apparatus . 9
6.1 General . 9
6.2 Sampler . 9
6.2.1 General. 9
6.2.2 Filters . 9
6.2.3 Midget impingers . 9
6.3 Sampling pump .10
6.4 Tubing .10
6.5 Flowmeter .10
6.6 Filtration and solid-phase extraction equipment .10
6.7 Liquid chromatographic system .10
6.7.1 Autosampler .10
6.7.2 Pumping system .10
6.7.3 Analytical column .10
6.7.4 Column oven .11
6.7.5 Post-column acid delivery pump .11
6.7.6 Detectors .11
7 Air sampling .11
7.1 Pre-sampling laboratory preparation .11
7.1.1 Cleaning of sampling equipment .11
7.1.2 Preparation of MAP-coated filter samplers .11
7.1.3 Preparation of extraction solution jars.11
7.2 Pre-sampling field preparation .11
7.2.1 Calibration of pump .11
7.2.2 Preparation of samplers .12
7.3 Collection of air samples .12
7.3.1 Filter sampling .12
© ISO 2019 – All rights reserved iii

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SIST ISO 17735:2019
ISO 17735:2019(E)

7.3.2 Impinger sampling .12
7.3.3 Sampling with an impinger followed by a filter .12
7.4 Blanks and negative controls .12
7.5 Bulk products .13
7.6 Shipment of samples .13
7.7 Filter test samples .13
7.8 Impinger test samples .13
8 HPLC analysis .14
8.1 Instrumental settings .14
8.2 HPLC programme.14
9 Data handling .15
9.1 Monomer measurement .15
9.2 Oligomer measurement (total detectable isocyanate) .16
10 Calibration and quality control .16
10.1 Standard matching solutions .16
10.2 Calibration curves .16
10.3 Blank tests .17
10.4 Bulk products .17
10.5 Quality control spikes .17
11 Calculations.17
11.1 Monomer .17
11.2 Oligomers (total detectable isocyanate) .18
12 Interferences .18
13 Determination of performance characteristics.19
13.1 General .19
13.2 Assessment of performance characteristics .20
13.2.1 Collection efficiency relative to particle size distribution.20
13.2.2 Air sampling .20
13.2.3 Analysis .21
13.2.4 Mass of compound in sample blank .25
13.2.5 Between-laboratory uncertainty contributions .26
13.2.6 Combined uncertainty .26
13.2.7 Expanded uncertainty .26
13.2.8 Uncertainty from performance criteria .26
Annex A (informative) Performance characteristics .27
Bibliography .29
iv © ISO 2019 – All rights reserved

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SIST ISO 17735:2019
ISO 17735:2019(E)

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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 2,
Workplace atmospheres.
This second edition cancels and replaces the first edition (ISO 17735:2009), which has been technically
revised. The main changes compared to the previous edition are as follows.
— Additional limit of detection information has been provided (Clause 1).
— The method has been used in high air concentrations successfully with a higher reagent concentration
in an impinger (5.3.1).
— During processing of impinger samples, rinsing the SPE cartridge with 6 ml dichloromethane has
been changed to rinsing with two consecutive 3 ml aliquots. This is more effective in removing all
of the butyl benzoate impinger solvent (7.8).
— The liquid chromatographic system has been adapted to use a smaller diameter analytical column
(6.7.3).
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.
© ISO 2019 – All rights reserved v

---------------------- Page: 7 ----------------------

SIST ISO 17735:2019
ISO 17735:2019(E)

Introduction
This document specifies the use of 1-(9-anthracenylmethyl)piperazine (MAP) to measure monomeric
and oligomeric isocyanate species in workplace atmospheres. MAP was designed to improve the
reliability of identification of isocyanate species in sample chromatograms and to improve the
accuracy of quantification of these species relative to established reagents. The high performance
liquid chromatography (HPLC) analysis uses a pH gradient to selectively accelerate the elution of
MAP derivatives of oligomeric isocyanates that might be unobservable in an isocratic analysis. The
[8]
performance of MAP has been compared to other reagents used for total isocyanate analysis , MAP has
been found to react with phenyl isocyanate (used as a model isocyanate) as fast as or faster than other
reagents commonly used for isocyanate analysis. The UV response of MAP derivatives is comparable
to that of 9-(methylaminomethyl)anthracene (MAMA) derivatives and considerably greater than other
commonly used reagents [approximately three times greater than 1-(2-methoxyphenyl)piperazine
(1-2MP) derivatives of aromatic isocyanates and 14 times greater than 1-2MP derivatives of aliphatic
isocyanates]. The compound-to-compound variability of UV response per isocyanate group for MAP
derivatives is smaller than the variability of any other commonly used reagent/detector combination
(the coefficient of variation is 3,5 % for five model isocyanates). This results in more accurate
quantification of detectable non-monomeric isocyanate species based on a calibration curve generated
from analysing standards of monomeric species. The monomeric species used for calibration is generally
the one associated with the product being analysed, but others could be used due to the very small
compound-to-compound response variability of the MAP derivatives. The intensity of fluorescence
response of MAP derivatives is comparable to that of MAMA derivatives and considerably greater
than other reagents (e.g. approximately 30 times more intense than that of tryptamine derivatives).
The compound-to-compound variability in fluorescence response has been found to be smaller than
that of MAMA derivatives but larger than that of tryptamine derivatives (MAMA = 59 % coefficient
of variation, MAP = 33 % coefficient of variation, and tryptamine = 16 % coefficient of variation for
5 model isocyanates). The compound-to-compound fluorescence variability of MAP derivatives is
considered too great for accurate quantification of non-monomeric isocyanate species based on
calibration with monomer standards. However, the sensitivity of the fluorescence detection makes
it especially suitable for quantification of low levels of monomer, and the selectivity is very useful to
designate an unidentified HPLC peak as a MAP derivative. MAP derivatives also give a strong response
by electrochemical detection. The pH gradient used in the HPLC analysis selectively accelerates the
elution of amines (MAP derivatives are amines) and is very strong (it accelerates MDI more than
100-fold). Re-equilibration to initial conditions is almost immediate. Many oligomeric species can be
measured in the 30 min MAP analysis that may be unobservable in a much longer isocratic analysis.
MAP has been used in several studies comparing it side-by-side with other methods. Reference [9]
found MAP impingers and NIOSH 5521 impingers (comparable to MDHS 25) to give comparable
results in spray painting environments. Reference [9] used MAP reagent, but the pH gradient was not
employed. Reference [10] compared MAP impingers with several other impinger methods (NIOSH 5521
and NIOSH 5522) and the double filter method. The average MAP oligomer value was substantially
higher than the other impinger methods and slightly higher than the double filter method. The pH
gradient was used in these MAP analyses. Reference [11] found that the MAP oligomer results compared
favourably against several other methods for measurement of oligomeric isocyanates in the collision
repair industry, and agreed well with the reference values.
[12]
The MAP method is currently available as NIOSH Method 5525 . The performance characteristics of
the method have been evaluated in Reference [13].
vi © ISO 2019 – All rights reserved

---------------------- Page: 8 ----------------------

SIST ISO 17735:2019
INTERNATIONAL STANDARD ISO 17735:2019(E)
Workplace atmospheres — Determination of total
isocyanate groups in air using 1-(9-anthracenylmethyl)
piperazine (MAP) reagent and liquid chromatography
1 Scope
This document specifies a method for the sampling and analysis of airborne organic isocyanates in
workplace air.
This document is applicable to a wide range of organic compounds containing isocyanate groups,
including monofunctional isocyanates (e.g. phenyl isocyanate), diisocyanate monomers [e.g.
1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate
(MDI), and isophorone diisocyanate (IPDI)], prepolymers (e.g. the biuret and isocyanurate of HDI), as
well as chromatographable intermediate products formed during production or thermal breakdown of
polyurethane.
In mixed systems of HDI and IPDI products, it is impossible to identify and quantify low levels of IPDI
monomer using this document, due to coelution of IPDI monomer with HDI-uretidinedione.
It is known that the method underestimates the oligomer in MDI-based products. Total isocyanate
group (NCO) is underestimated in MDI-based products by about 35 % as compared to dibutylamine
titration.
The method has been successfully modified to be used with LC-MS-MS for TDI monomer using an
isocratic 70 % acetonitrile/30 % 10 mM ammonium formate mobile phase.
The useful range of the method, expressed in moles of isocyanate group per species per sample, is
−10 −7
approximately 1 × 10 to 2 × 10 . The instrumental detection limit for the monomers using both
ultraviolet (UV) detection and fluorescence (FL) detection is about 2 ng monomer per sample. The
useful limit of detection for the method using reagent impregnated filters is about 10 ng to 20 ng
−3
monomer per sample for both UV and FL detection. For a 15 l sample, this corresponds to 0,7 µg/m to
−3
1,4 µg/m . For impinger samples, which require solid phase extraction, experience has shown that the
useful limit of detection is about 30 ng to 80 ng monomer per sample.
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.
EN 1232, Workplace atmospheres — Pumps for personal sampling of chemical agents — Requirements and
test methods
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
© ISO 2019 – All rights reserved 1

---------------------- Page: 9 ----------------------

SIST ISO 17735:2019
ISO 17735:2019(E)

4 Principle
A measured volume of air is drawn through either an impinger containing a solution of
1-(9-anthracenylmethyl)piperazine (MAP), a filter impregnated with MAP, or a sampling train
consisting of an impinger followed by an impregnated filter. The choice of sampler depends on the
chemical and physical characteristics of the airborne isocyanate[14]. If an impinger is used, the
solution is subjected to solid-phase extraction (SPE) and the eluate is concentrated and analysed by
reverse phase high performance liquid chromatography (HPLC) with ultraviolet (UV) absorbance
and fluorescence (FL) detection in series. If an i
...

SLOVENSKI STANDARD
oSIST ISO/DIS 17735:2018
01-september-2018
=UDNQDGHORYQHPPHVWX'RORþHYDQMHVNXSLQL]RFLDQDWRYY]UDNX]UHDJHQWRP
DQWUDFHQLOPHWLOSLSHUD]LQ0$3LQWHNRþLQVNRNURPDWRJUDILMR
Workplace atmospheres - Determination of total isocyanate groups in air using 1-(9-
anthracenylmethyl)piperazine (MAP) reagent and liquid chromatography
Air des lieux de travail - Dosage des groupements isocyanates totaux dans l'air par
réaction avec la 1-(9-anthracénylméthyl)pipérazine (MAP) et par chromatographie en
phase liquide
Ta slovenski standard je istoveten z: ISO/DIS 17735
ICS:
13.040.30 Kakovost zraka na delovnem Workplace atmospheres
mestu
oSIST ISO/DIS 17735:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST ISO/DIS 17735:2018

---------------------- Page: 2 ----------------------
oSIST ISO/DIS 17735:2018
DRAFT INTERNATIONAL STANDARD
ISO/DIS 17735
ISO/TC 146/SC 2 Secretariat: ANSI
Voting begins on: Voting terminates on:
2018-02-15 2018-05-10
Workplace atmospheres — Determination of total
isocyanate groups in air using 1-(9-anthracenylmethyl)
piperazine (MAP) reagent and liquid chromatography
Air des lieux de travail — Dosage des groupements isocyanates totaux dans l'air par réaction avec la
1-(9-anthracénylméthyl)pipérazine (MAP) et par chromatographie en phase liquide
ICS: 13.040.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 17735:2018(E)
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 SUPPORTING DOCUMENTATION. ISO 2018

---------------------- Page: 3 ----------------------
oSIST ISO/DIS 17735:2018
ISO/DIS 17735:2018(E) ISO 17735:2009(E)

Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Principle. 2
4 Reagents and materials . 3
5 Apparatus . 8
6 Air sampling . 11
6.1 Pre-sampling laboratory preparation . 11
6.2 Pre-sampling field preparation . Error! Bookmark not defined.
6.3 Collection of air samples . Error! Bookmark not defined.
6.4 Blanks and negative controls . 12
6.5 Bulk products . 12
6.6 Shipment of samples . 12
6.7 Filter test samples . 13
6.8 Impinger test samples . 13
7 HPLC analysis . 13
7.1 Instrumental settings . 13
7.2 HPLC programme . 14
8 Data handling . 15
8.1 Monomer measurement . 15
8.2 Oligomer measurement (total detectable isocyanate) . 15
9 Calibration and quality control . 16
9.1 Standard matching solutions . 16
9.2 Calibration curves . 16
9.3 Blank tests . 16
9.4 Bulk products . 16
9.5 Quality control spikes . 16
10 Calculations . 17
10.1 Monomer. 17
10.2 Oligomers (total detectable isocyanate) . 18
11 Interferences . 18
12 Determination of performance characteristics. 18
12.1 Introduction . 18
COPYRIGHT PROTECTED DOCUMENT
12.2 Assessment of performance characteristics. 19
© ISO 2018
Annex A (informative) Performance characteristics . 28
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
Bibliography . Error! Bookmark not defined.
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’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
© ISO 2009 – All rights reserved iii

---------------------- Page: 4 ----------------------
oSIST ISO/DIS 17735:2018
ISO/DIS 17735:2018(E)
Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Principle. 2
4 Reagents and materials . 3
5 Apparatus . 8
6 Air sampling . 11
6.1 Pre-sampling laboratory preparation . 11
6.2 Pre-sampling field preparation . Error! Bookmark not defined.
6.3 Collection of air samples . Error! Bookmark not defined.
6.4 Blanks and negative controls . 12
6.5 Bulk products . 12
6.6 Shipment of samples . 12
6.7 Filter test samples . 13
6.8 Impinger test samples . 13
7 HPLC analysis . 13
7.1 Instrumental settings . 13
7.2 HPLC programme . 14
8 Data handling . 15
8.1 Monomer measurement . 15
8.2 Oligomer measurement (total detectable isocyanate) . 15
9 Calibration and quality control . 16
9.1 Standard matching solutions . 16
9.2 Calibration curves . 16
9.3 Blank tests . 16
9.4 Bulk products . 16
9.5 Quality control spikes . 16
10 Calculations . 17
10.1 Monomer. 17
10.2 Oligomers (total detectable isocyanate) . 18
11 Interferences . 18
12 Determination of performance characteristics. 18
12.1 Introduction . 18
12.2 Assessment of performance characteristics. 19
Annex A (informative) Performance characteristics . 28
Bibliography . Error! Bookmark not defined.

© ISO 2018 – All rights reserved iii

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oSIST ISO/DIS 17735:2018
ISO/DIS 17735:2018(E)
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 17735 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 2, Workplace
atmospheres.
iv © ISO 2018 – All rights reserved

---------------------- Page: 6 ----------------------
oSIST ISO/DIS 17735:2018
ISO/DIS 17735:2018(E)
Introduction
This International Standard specifies the use of 1-(9-anthracenylmethyl)piperazine (MAP) to measure
monomeric and oligomeric isocyanate species in workplace atmospheres. MAP was designed to improve the
reliability of identification of isocyanate species in sample chromatograms and to improve the accuracy of
quantification of these species relative to established reagents. The high performance liquid chromatography
(HPLC) analysis uses a pH gradient to selectively accelerate the elution of MAP derivatives of oligomeric
isocyanates that might be unobservable in an isocratic analysis. The performance of MAP has been compared
to other reagents used for total isocyanate analysis (Reference [7]). MAP has been found to react with phenyl
isocyanate (used as a model isocyanate) as fast as or faster than other reagents commonly used for
isocyanate analysis. The UV response of MAP derivatives is comparable to that of 9-
(methylaminomethyl)anthracene (MAMA) derivatives and considerably greater than other commonly used
reagents [approximately three times greater than 1-(2-methoxyphenyl)piperazine (1-2MP) derivatives of
aromatic isocyanates and 14 times greater than 1-2MP derivatives of aliphatic isocyanates]. The compound-
to-compound variability of UV response per isocyanate group for MAP derivatives is smaller than the
variability of any other commonly used reagent/detector combination (the coefficient of variation is 3,5 % for
five model isocyanates). This results in more accurate quantification of detectable non-monomeric isocyanate
species based on a calibration curve generated from analysing standards of monomeric species. The
monomeric species used for calibration is generally the one associated with the product being analysed, but
others could be used due to the very small compound-to-compound response variability of the MAP
derivatives. The intensity of fluorescence response of MAP derivatives is comparable to that of MAMA
derivatives and considerably greater than other reagents (e.g. approximately 30 times more intense than that
of tryptamine derivatives). The compound-to-compound variability in fluorescence response has been found to
be smaller than that of MAMA derivatives but larger than that of tryptamine derivatives (MAMA = 59 %
coefficient of variation, MAP = 33 % coefficient of variation, and tryptamine = 16 % coefficient of variation for
5 model isocyanates). The compound-to-compound fluorescence variability of MAP derivatives is considered
too great for accurate quantification of non-monomeric isocyanate species based on calibration with monomer
standards. However, the sensitivity of the fluorescence detection makes it especially suitable for quantification
of low levels of monomer, and the selectivity is very useful to designate an unidentified HPLC peak as a MAP
derivative. MAP derivatives also give a strong response by electrochemical detection. The pH gradient used in
the HPLC analysis selectively accelerates the elution of amines (MAP derivatives are amines), and is very
strong (it accelerates MDI more than 100-fold). Re-equilibration to initial conditions is almost immediate. Many
oligomeric species can be measured in the 30 min MAP analysis that may be unobservable in a much longer
isocratic analysis.
MAP has been used in several studies comparing it side-by-side with other methods. Reference [8] found
MAP impingers and NIOSH 5521 impingers (comparable to MDHS 25) to give comparable results in spray
painting environments. Reference [8] used MAP reagent, but the pH gradient was not employed.
Reference [9] compared MAP impingers with several other impinger methods (NIOSH 5521 and NIOSH 5522)
and the double filter method. The average MAP oligomer value was substantially higher than the other
impinger methods and slightly higher than the double filter method. The pH gradient was used in these MAP
analyses. Reference [10] found that the MAP oligomer results compared favorably against several other
methods for measurement of oligomeric isocyanates in the collision repair industry, and agreed well with the
reference values.
The MAP method is currently available as NIOSH Method 5525 (Reference [11]). The performance
characteristics of the method have been evaluated in Reference [12].

© ISO 2018 – All rights reserved v

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oSIST ISO/DIS 17735:2018

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oSIST ISO/DIS 17735:2018
INTERNATIONAL STANDARD ISO /DIS 17735:2018(E)

Workplace atmospheres — Determination of total isocyanate
groups in air using 1-(9-anthracenylmethyl)piperazine (MAP)
reagent and liquid chromatography
1 Scope
1.01 This International Standard gives general guidance for the sampling and analysis of airborne organic
isocyanates in workplace air.
1.02 This International Standard is appropriate for a wide range of organic compounds containing isocyanate
groups, including monofunctional isocyanates (e.g. phenyl isocyanate), diisocyanate monomers (e.g.
1,6-hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 4,4’-diphenylmethane diisocyanate
(MDI), and isophorone diisocyanate (IPDI)), prepolymers (e.g. the biuret and isocyanurate of HDI), as well
as chromatographable intermediate products formed during production or thermal breakdown of
polyurethane.
1.03 In mixed systems of HDI and IPDI products, it is impossible to identify and quantify low levels of IPDI
monomer using this International Standard, due to coelution of IPDI monomer with HDI-uretidinedione.
1.04 It is known that the method underestimates the oligomer in MDI-based products. Total isocyanate group
(NCO) will be underestimated in MDI-based products by about 35% as compared to dibutylamine titration.
1.05 The method has been successfully modified to be used with LC-MS-MS for TDI monomer using an
isocratic 70% acetonitrile/30% 10 mM ammonium formate mobile phase.
1.06 The useful range of the method, expressed in moles of isocyanate group per species per sample, is
−10 −7
approximately 1 × 10 to 2 × 10 . The instrumental detection limit for the monomers using both
ultraviolet (UV) detection and fluorescent (FL) detection is about 2 ng monomer per sample. The useful
limit of detection for the method using reagent impregnated filters is about 10-20 ng monomer per sample
-3
for both UV and FL detection. For a 15 l sample, this corresponds to 0.7-1.4 µg.m . For impinger
samples, which require solid phase extraction, experience has shown that the useful limit of detection is
about 30-80 ng monomer per sample.
2 Normative references
2.01 The following referenced documents are indispensable for the application 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.
2.02 ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic
method for the determination of repeatability and reproducibility of a standard measurement method.
2.03 ISO 16200-1, Workplace air quality — Sampling and analysis of volatile organic compounds by solvent
desorption/gas chromatography — Part 1: Pumped sampling method.
© ISO 2018 – All rights reserved 1

---------------------- Page: 9 ----------------------
oSIST ISO/DIS 17735:2018
ISO/DIS 17735:2018(E)
3 Principle
3.01 A measured volume of air is drawn through either an impinger containing a solution of
1-(9-anthracenylmethyl)piperazine (MAP), a filter impregnated with MAP, or a sampling train consisting of
an impinger followed by an impregnated filter. The choice of sampler depends on the chemical and
physical characteristics of the airborne isocyanate (Reference [13]). If an impinger is used, the solution is
subjected to solid-phase extraction (SPE) and the eluate is concentrated and analysed by reverse phase
high performance liquid chromatography (HPLC) with ultraviolet (UV) absorbance and fluorescence (FL)
detection in series. If an impregnated filter is used for sampling, it is extracted with solvent either in the
field after completion of sampling or in the laboratory. Waiting to extract the filter until after the sample
has been received by the analytical laboratory is acceptable only for analysis of isocyanates collected as
vapour. This solution is filtered and analysed by HPLC/UV/FL. Isocyanate-derived peaks are identified
based on their UV and FL responses and by comparison with the chromatogram of a derivatised bulk
isocyanate product if available. Quantification of compounds for which analytical standards are available
(generally monomers) is achieved by comparison of the FL peak height of the sample peak with the FL
peak height of standard matching solutions. Quantification of compounds for which analytical standards
are not available is achieved by comparison of the UV area of the sample peak with the UV area of the
appropriate monomer standard (i.e. the monomer from which the isocyanate product is derived).
3.02 Structures of some common diisocyanate monomers are shown in Figure 1.

Key
1 methyl isocyanate
2 butyl isocyanate
2 © ISO 2018 – All rights reserved

---------------------- Page: 10 ----------------------
oSIST ISO/DIS 17735:2018
ISO/DIS 17735:2018(E)
3 phenyl isocyanate
4 4,4’-MDI
5 2,6-TDI
6 HDI
7 2,4-TDI
8 IPDI
9 hydrogenated MDI (HMDI)
Figure 1 — Structures of some common isocyanates
4 Reagents and materials
4.01 CAUTION — Observe appropriate safety precautions when preparing reagents. Carry out preparations
under a fume hood to avoid exposure to solvents, isocyanates or other volatile reagents. Wear nitrile
gloves when manipulating reagents and solvents.
4.02 During the analysis, unless otherwise stated, use only reagents of HPLC grade or better, and water of
HPLC grade. The following list of reagents are used for the below procedures and for the procedures in
clauses 5 and 6: 9-(chloromethyl)anthracene, 1,6-hexamethylene diisocyanate, 4,4’-
methylenebis(cyclohexyl isocyanate), 4,4’-methylenebis(phenyl isocyanate), acetic anhydride,
acetonitrile, butyl benzoate, dichloromethane, dimethyl formamide, ethyl acetate, formic acid, hexane,
hydrochloric acid, isophorone diisocyanate, methanol, nitric acid, non-chromate/concentrated sulfuric
acid-based cleaning solution, phosphoric acid, piperazine, prepurified nitrogen compressed gas, toluene,
tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, and triethylamine.
4.03 The following materials are used for the below procedures and for the procedures in clauses 5 and 6:
amber jars with polytetrafluoroethylene (PTFE)-lined caps, Büchner funnel, cool packs, cooler, disposable
glass vials (7 ml and 20 ml, PTFE-lined caps), dropping funnel, filter holder (open- or closed-face 37 mm
polystyrene cassettes, 13 mm polypropylene cassettes), filter paper, glass chromatography column
(short), glass fibre filter (37 mm or 13 mm, binder-free), magnetic stirring bar, nylon filter (0,45 µm),
round-bottomed flasks (250 ml two-necked; 100 ml one-necked; 1000 ml one-necked), separating funnel,
silica gel (high-purity grade, 60 Å, 70-230 mesh), SPE tubes (normal phase silica gel, 6 ml/500 mg),
syringe barrel (empty, polypropylene), syringe filter (0,45 µm PTFE), TLC plates (green fluorescing F or
254
blue fluorescing F254s), tubing (fluoroelastomer and plastic, rubber, or other suitable material 900 mm
[1]
long), volumetric flask (10 ml one-mark, ISO 1042 , class A), wax bath.
4.1 MAP reagent
4.1.01 MAP is prepared by the reaction of 9-(chloromethyl)anthracene with piperazine as shown in Figure 2.
4.1.02 The procedure is as follows.
4.1.03 Dissolve 10,8 mmol (2,47 g) of 9-(chloromethyl)anthracene (98 % mass fraction) in 25 ml
dichloromethane. Place this solution in a dropping funnel.
4.1.04 Dissolve 54,4 mmol (4,69 g) of piperazine (99 % mass fraction) and 21,8 mmol (3,04 ml) of
triethylamine (99,5 % mass fraction) in 37 ml dichloromethane. Place this solution in a 250 ml two-
necked round-bottomed flask with a magnetic stirring bar.
4.1.05 While stirring this solution, add the 9-(chloromethyl)anthracene solution dropwise over a 30 min period.
Rinse down the dropping funnel with an additional 10 ml of dichloromethane. Allow the reaction to
continue while stirring for at least 2 h.
© ISO 2018 – All rights reserved 3

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oSIST ISO/DIS 17735:2018
ISO/DIS 17735:2018(E)
4.1.06 Using a separating funnel, wash the reaction mixture three times with 130 ml water by shaking
vigorously for 1 min. Discard the emulsion that forms after the first wash, which contains primarily an
impurity and not MAP. Discard the aqueous washings.
4.1.07 Place the washed MAP solution in a weighed 100 ml round-bottomed flask. Allow the dichloromethane
to evaporate under a steady stream of nitrogen. Weigh the flask with the residue to obtain an
approximate yield. This crude MAP can be safely stored in a freezer until further purification.
4.1.08 MAP is purified by column chromatography followed by sublimation. Using a glass chromatography
column of internal diameter approximately 50 mm, add a slurry of silica gel (high-purity, 60 Å, 70-230
mesh) in toluene until the silica gel bed is approximately 80 mm deep. Wash the sides of the column
down with toluene and allow the toluene to run through the column until the toluene is even with the
silica gel surface.
4.1.09 Dissolve the crude MAP in 80 ml of toluene. Sonicate the mixture for 5 min and filter through filter paper.
Save the filtrate. Suspend the residue in 20 ml toluene, sonicate for 5 min, and filter through filter paper.
Discard the residue. Combine the filtrates and carefully load them onto the top of the silic
...