Ambient air — Determination of particle-phase polycyclic aromatic hydrocarbons by high performance liquid chromatography

ISO 16362:2005 specifies sampling, cleanup and analysis procedures for the quantitative determination of low volatility (particle-bound) polycyclic aromatic hydrocarbons (PAHs) in ambient air. For sampling, a low-volume or a medium/high-volume sampling device may be used. Sampling times between 1 h and 24 h are possible. The sampling volume flow rates can range from 1 m/h to 4 m/h ("low volume sampler") or from 10 m/h to about 90 m/h ("medium/high-volume sampler"). In any case, the linear face velocity at the collection filter should range between about 0,5 m/s and 0,9 m/s. The method has been validated for sampling periods up to 24 h. The detection limits for single PAHs and the standard deviations resulting from duplicate measurements are listed. ISo 16362:2005 describes a sampling and analysis procedure for PAH that involves collection from air onto a filter followed by analysis using high performance liquid chromatography usually with fluorescence detector (FLD). The use of a diode array detector (DAD) is possible. The combination of both detector types is also possible. Total suspended particulate matter is sampled. Generally, compounds having a boiling point above 430 °C (vapour pressure less than 10-9 kPa at 25 °C, e.g. chrysene, benz[a]anthracene) can be collected efficiently on the filter at low ambient temperatures (e.g. below 10 °C). In contrast, at higher temperatures (above 30 °C, see also ISO 12884[1]), only PAHs having boiling points above 475 °C (vapour pressure less than 10-10 kPa at 25 °C) are determined quantitatively.

Air ambiant — Détermination des particules d'hydrocarbures aromatiques polycycliques par chromatographie liquide à haute performance

Zunanji zrak - Določevanje policikličnih aromatskih ogljikovodikov v delcih s tekočinsko kromatografijo visoke ločljivosti

General Information

Status
Published
Publication Date
17-Feb-2005
Current Stage
9060 - Close of review
Start Date
18-Jun-2008

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INTERNATIONAL ISO
STANDARD 16362
First edition
2005-02-15
Ambient air — Determination of particle-
phase polycyclic aromatic hydrocarbons
by high performance liquid
chromatography
Air ambiant — Détermination des particules d'hydrocarbures
aromatiques polycycliques par chromatographie liquide à haute
performance
Reference number
ISO 16362:2005(E)
ISO 2005
---------------------- Page: 1 ----------------------
ISO 16362:2005(E)
PDF disclaimer

This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but

shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In

downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat

accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.

Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation

parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In

the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

© ISO 2005

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or

ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2005 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 16362:2005(E)
Contents Page

Foreword............................................................................................................................................................ iv

Introduction ........................................................................................................................................................ v

1 Scope...................................................................................................................................................... 1

2 Terms and definitions........................................................................................................................... 1

3 Symbols and abbreviated terms.......................................................................................................... 2

3.1 Symbols ................................................................................................................................................. 2

3.2 Abbreviated terms................................................................................................................................. 2

4 Principle of the procedure.................................................................................................................... 2

5 Reagents, apparatus and materials .................................................................................................... 2

6 Measurement procedure ...................................................................................................................... 5

6.1 Sampling ................................................................................................................................................ 5

6.2 Sample preparation............................................................................................................................... 5

6.3 HPLC analysis ....................................................................................................................................... 6

7 Establishment of the calibration function and verification of the measurement values............... 6

7.1 Identification.......................................................................................................................................... 6

7.2 Instrument calibration .......................................................................................................................... 7

7.3 Determination of response factors and quantification ..................................................................... 7

7.4 Determination of the extraction efficiency ......................................................................................... 9

8 Calculation of the result ....................................................................................................................... 9

9 Performance characteristics................................................................................................................ 9

9.1 Standard deviations of the overall measurement procedure........................................................... 9

9.2 Detection limits ..................................................................................................................................... 9

10 Interferences........................................................................................................................................ 11

11 Quality assurance ............................................................................................................................... 11

12 Test report............................................................................................................................................ 12

Annex A (informative) General information ................................................................................................... 13

Annex B (informative) Examples of operation parameters for HPLC analysis with FLD and DAD in

series.................................................................................................................................................... 14

Annex C (informative) Extraction efficiencies for some PAH compounds................................................. 17

Annex D (informative) Results of duplicate measurements......................................................................... 18

Annex E (informative) Comparison measurements and invariance test of the PAH profiles................... 20

Annex F (informative) Physical constants of PAHs ...................................................................................... 21

Annex G (informative) List of HPLC columns................................................................................................ 25

Bibliography ..................................................................................................................................................... 26

© ISO 2005 – All rights reserved iii
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ISO 16362:2005(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 16362 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 3, Ambient

atmospheres.
iv © ISO 2005 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 16362:2005(E)
Introduction

Several polycyclic aromatic hydrocarbons (PAHs) are considered to be potential human carcinogens. PAHs

are emitted into the atmosphere primarily through combustion of fossil fuel and wood. Two- and three-ring

PAHs are typically present in urban air at concentrations ranging from ten to several hundred nanograms per

cubic metre (ng/m ); those with four or more rings are usually found at concentrations of a few nanograms per

cubic metre or lower. PAHs possess saturation vapour pressures at 25 °C that range from 10 kPa to less

−13 −8

than 10 kPa. Those with vapour pressures above 10 kPa may be substantially distributed between the

gas phase and particle-associated (particulate) phase in the atmosphere. The distribution between phases

depends on ambient temperature, humidity, types and concentrations of PAHs and particulate matter, and

residence time in the air. PAHs, especially those having vapour pressures above 10 kPa, tend to vaporize

from particle filters during sampling.

This International Standard allows the determination of low volatility, particle-bound PAHs, in contrast to

[1]

ISO 12884 which allows the measurement of PAHs in the gas phase. This International Standard allows the

use of a range of sampler flowrates, and requires the use of high performance liquid chromatography (HPLC)

with the detection carried out by either fluorescence detection or UV absorption.

© ISO 2005 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 16362:2005(E)
Ambient air — Determination of particle-phase polycyclic
aromatic hydrocarbons by high performance liquid
chromatography
1 Scope

This International Standard specifies sampling, clean-up and analysis procedures for the quantitative

determination of low volatility (particle-bound) polycyclic aromatic hydrocarbons (PAHs) in ambient air. For

sampling, a low-volume or a medium/high-volume sampling device may be used. Sampling times between 1 h

3 3

and 24 h are possible. The sampling volume flowrates can range from 1 m /h to 4 m /h (“low volume

3 3

sampler”) or from 10 m /h to about 90 m /h (“medium/high-volume sampler”). In any case, the linear face

velocity at the collection filter should range between about 0,5 m/s and 0,9 m/s.

The method has been validated for sampling periods up to 24 h. The detection limits for single PAHs and the

standard deviations resulting from duplicate measurements are listed in 9.2 and Annex D respectively.

This International Standard describes a sampling and analysis procedure for PAH that involves collection from

air onto a filter followed by analysis using high performance liquid chromatography usually with fluorescence

detector (FLD). The use of a diode array detector (DAD) is possible. The combination of both detector types is

also possible (see Annex B). Total suspended particulate matter is sampled.

Generally, compounds having a boiling point above 430 °C (vapour pressure less than 10 kPa at 25 °C, e.g.

chrysene, benz[a]anthracene) can be collected efficiently on the filter at low ambient temperatures (e.g. below

[1]

10 °C). In contrast, at higher temperatures (above 30 °C, see also ISO 12884 ), only PAHs having boiling

−10

points above 475 °C (vapour pressure less than 10 kPa at 25 °C) are determined quantitatively

(see Annex F).
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
blank value solution

solution which contains the chemicals used in making up the sample solution batch and the constituents

influencing the measurement in the same or similar concentration as the sample to be analysed, but to which

the compound to be determined has expressly not been added
2.2
low-volume sampling device
3 3
sampling device with a volume flowrate of 1 m /h to 4 m /h
2.3
medium/high-volume sampling device
3 3
sampling device with a volume flowrate of 10 m /h to about 90 m /h
© ISO 2005 – All rights reserved 1
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ISO 16362:2005(E)
3 Symbols and abbreviated terms
3.1 Symbols
A peak area of component i
A peak area of internal standard
ρ mass concentration
f response factors, slope of straight line
m mass of component i
m mass of internal standard
M relative molecular mass (molecular weight)
V volume
3.2 Abbreviated terms
ASE accelerated solvent extraction
b.p. boiling point
DAD diode array detector (UV absorption)
FLD fluorescence detector
HPLC high performance liquid chromatography
PAH polycyclic aromatic hydrocarbon
SOP standard operating procedure
UV ultraviolet
WHO World Health Organization
4 Principle of the procedure
3 3

For sampling, sampling devices with volume flowrates from 1 m /h to about 90 m /h may be used. The

particulate matter, onto which the PAHs are adsorbed, is collected on glass or quartz fibre filters.

The PAHs are extracted and the extract concentrated. If necessary, the extracts may be cleaned by column

chromatography using silica gel.

The PAHs are determined by HPLC using DAD or FLD. For quality assurance, internal standards are added.

5 Reagents, apparatus and materials
5.1 Reagents

5.1.1 Solvents for analysis: water, acetonitrile, toluene (all solvents of chromatographic grade).

2 © ISO 2005 – All rights reserved
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ISO 16362:2005(E)

5.1.2 Solvents for sample preparation: chromatographic grade toluene, cyclohexane and acetonitrile.

The chromatograms of the solvents obtained under the conditions of the illustrative example shall not exhibit

any interfering peaks.
5.1.3 Helium, purity 99,999 %; for degasification of solvents.

To avoid interferences, no plastic hoses shall be employed, preferably metal hoses are recommended.

5.1.4 Internal standard

If using DAD: indeno[1,2,3-cd]fluoranthene dissolved in toluene, mass concentration e.g. 3 µg/ml (see 6.2).

If using FLD: 6-methylchrysene.
5.1.5 Calibration standards
Cyclopenta[c,d]pyrene CPP
Benz[a]anthracene BaA
Chrysene CHR
Benzo[b]fluoranthene BbF
Benzo[j]fluoranthene BjF
Benzo[k]fluoranthene BkF
Benzo[a]pyrene BaP
Benzo[e]pyrene BeP
Indeno[1,2,3-cd]pyrene INP
Dibenz[a,h]anthracene DBahA
Dibenz[a,c]anthracene DBacA
Benzo[g,h,i]perylene BghiP
Anthanthrene ANT
Coronene COR
Dibenzo[a,l]pyrene DBalP
Dibenzo[a,i]pyrene DBaiP
Dibenzo[a,e]pyrene DBaeP
Dibenzo[a,h]pyrene DBahP
Benzo[a]chrysene (= picene) BaC
5.2 Apparatus

5.2.1 Sampling device, consisting of the following parts (commercially available).

5.2.1.1 Sampling head, usually containing the filter.
© ISO 2005 – All rights reserved 3
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ISO 16362:2005(E)
5.2.1.2 Pumping system, e.g. sliding vane-pump or turbine.

5.2.1.3 Volume meter, for measuring the sample volume or a flowrate-measuring device.

5.2.1.4 Electronic or mechanical device, to establish a constant flow.
5.2.1.5 Timer, for selecting the time and duration of the sampling.
5.2.1.6 Blunt tweezers (optional), for handling the filters.
5.2.2 Sample preparation equipment

The PAH extraction (see 7.2) is carried out using ordinary laboratory equipment. This may include:

5.2.2.1 Flasks/reflux condenser, round-bottomed flask (e.g. 250 ml, or 100 ml if the small filter device is

used) with matched reflux condenser and heating bath, or
5.2.2.2 Ultrasonic bath, beaker, capacity e.g. 50 ml or 100 ml, or

5.2.2.3 Soxhlet extractor, capacity e.g. 30 ml to 50 ml, cellulose extraction thimble, round-bottomed

flask (100 ml) with reflux condenser and heating bath, or

5.2.2.4 ASE apparatus, device for extracting samples at elevated temperatures and under high pressure.

5.2.2.5 Vacuum pump, e.g. a membrane or water-jet pump.
5.2.2.6 Centrifuge, with inserts; e.g. of volume 20 ml each.

5.2.2.7 Chromatography column, internal diameter e.g. 10 mm, length 230 mm (silica gel column).

5.2.3 Analytical apparatus

5.2.3.1 High performance liquid chromatograph, fitted with an isothermal column device, solvent

purge system, gradient pump system and a FLD or DAD.

5.2.3.2 Separation columns, reverse phase-sorbent columns optimized for PAH analysis (see Annex G).

5.2.3.3 Recording equipment, work station with screen and printer/plotter for acquiring, processing,

storing and interpreting the data and the possibility of a later baseline correction.

5.2.3.4 GC microliter syringes, suitable for metering aliquots.
5.3 Materials

5.3.1 Collection filter, glass or quartz fibre filters, collection efficiency better than 99,9 % for particles

< 0,5 µm in diameter, without organic binder, appropriate for the sampling device (circular or square).

NOTE Filters coated or impregnated with polytetrafluoroethene (PTFE) have been used for collection of particle-

[2]

associated PAHs . Use of these filters, in lieu of those specified, requires validation of their performance by the user.

5.3.2 Sorbent for column chromatography

Silica gel, high purity grade, type 60, particle diameter 70 µm to 200 µm; 15 % mass fraction of water is added

24 h before use. To pack the column, a slurry is formed of 10 g of moistened silica gel in 40 ml of cyclohexane.

The slurry, freed from air bubbles by shaking, is packed into the chromatography column. Prior to use, the

cyclohexane is drawn off until the level of liquid drops to the surface of the silica gel layer.

4 © ISO 2005 – All rights reserved
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ISO 16362:2005(E)
6 Measurement procedure
6.1 Sampling
Choose a sampling device appropriate to the measurement task.

Label each collection filter in the laboratory, and, by means of tweezers, place it into the appropriate filter

holder. Ensure that the labelling material is not extracted. Fix the filter with a supporting ring. Put the filter

holder, with the filter inserted, into a Petri dish and place it in an airtight shipping container (transport box) for

transport to the measuring site. At the measuring site, insert the filter holder containing the filter into the

sampling head, which is connected to the suction tube, and fix it.

Set the sampling time from 1 h to 24 h, depending on the sampling task. Set the pump and the timer in

operation synchronously.

If the flow-controlling device is used in combination with a total volume meter, the sample volume is derived

from the volume meter readings at the beginning and the end of the sampling period.

If the flow-controlling device is combined with a flowrate-measuring device, the sample volume is derived from

the average flowrate (calculated from the flowrates at the least at the beginning and end of the measurement

period) and the elapsed time.

The flowrate-measuring device should also be used to check proper operation of the flow-controlling device at

the beginning and end of the sampling period.

Turn the pump off after sampling. Remove the filter holder with the exposed filter from the sampling head. Put

the filter holder containing the filter again into a Petri dish and place it in an airtight shipping container

(transport box) with the exposed filter side facing upwards for transport. Transport the shipping container

(transport box) horizontally. In the laboratory, remove the exposed filter from the filter holder with the aid of

tweezers.

Prior to extraction, store the filter in the dark at ambient temperature or below.

At least 10 % of the samples, or a minimum of one per sampling site if fewer than 10 samples are taken at the

site, shall be field blanks.
6.2 Sample preparation

Check the purity of the filters and glassware and the purity of the solvents and reagents. For this purpose, add

the internal standard solution to an unexposed filter and subject it to the entire analytical procedure (blank

value).

The blank values are not taken into account in the calculation, but shall not exceed 10 % of the value of the

sample or 10 % of a limit/guide value to be monitored.

Protect the samples and sample solutions against direct light during preparation.

For the extraction, place the filter in a 250 ml round-bottomed flask, cover it with 150 ml of toluene (or 70 ml of

toluene in a 100 ml round-bottomed flask if small filters are used) and add then 50 µl of the internal standard

[3]

solution (see 5.2.2.3). Toluene is especially suitable for the extraction of PAHs . If other solvents (e.g.

dichloromethane, acetonitrile) are used, the procedure shall have been validated using NIST standards. Insert

the reflux condenser and heat the contents of the flask to boiling for about 20 min. Separate the extract from

the filter material and dust particles by filtration.
© ISO 2005 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 16362:2005(E)
The extraction may also be performed quantitatively by various other methods:
 in a Soxhlet apparatus (toluene: 8 h, at least 10 cycles per hour);
 in the ultrasonic bath in a beaker (toluene: at least 15 min);

 in an ultrasonic bath followed by centrifugation. The filter is cut into pieces and placed in centrifuge tube,

followed by the addition of 15 ml toluene. The tubes are placed in the bath and extracted for 15 min. They

are then centrifuged (10 min, 3 000 r/min) and the solvent is decanted. The whole extraction procedure is

repeated. Both extraction solvents are combined;

 by accelerated solvent extraction (ASE). The filter is placed in the extraction vessel and extracted at a

temperature of 150 °C with toluene.
All methods shall be validated.

Concentrate the toluene solution to few microlitres under reduced pressure (e.g. 13 kPa). Keep this

evaporation step under observation at all times.

NOTE If evaporation is continued to dryness and the residue allowed to remain for a time in a vacuum, some PAHs

could be lost.
If further clean-up is necessary, add 2 ml of cyclohexane.

Add the cyclohexane solution to the pre-prepared silica gel column (see 5.2.2.7) using a syringe. Rinse the

flask then with 2 ml of cyclohexane which is also added with a syringe to the silica gel column. Carry out the

elution using 100 ml of cyclohexane. To remove the cyclohexane, concentrate the eluate to a volume of a few

milliliters and evaporate it then under a nitrogen stream almost to dryness. Dissolve the residue then in the

correct solvent for injection into the HPLC column, e.g. 100 µl of acetonitrile.

NOTE If the origin of the air sample is known and interferents are low, the clean-up using a silica gel column may be

unnecessary.

If the extract is not analysed immediately, it shall be stored in a refrigerator. Before analysis, it is allowed to

warm to room temperature.
6.3 HPLC analysis
Inject an aliquot of the sample (e.g. 20 µl) into the HPLC apparatus.

An example of operation conditions for HPLC analysis with FLD and DAD in series is given in Annex B.

7 Establishment of the calibration function and verification of the measurement
values
7.1 Identification

The separation conditions are optimized with aid of multi-component calibration standard solutions (see 5.1.5),

which gives adequate separation of the compounds of interest.

A component in the sample is primarily identified by comparison of its retention time to that of the same

substance in the calibration solution analysed under identical conditions. The level of identity shall be reported.

The concentrations of the calibration standards should be in the range of (depending on the measurement

task):
 2 ng/ml to 200 ng/ml, when a FLD is used;
 20 ng/ml to 1 000 ng/ml, when a DAD is used.
6 © ISO 2005 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 16362:2005(E)
7.2 Instrument calibration

Prepare calibration standard solutions of different concentrations for each new substance i to be determined

using acetonitrile. The calibration does not include the overall measurement procedure. Handle the calibration

standard solutions identically to the sample solutions.

Starting with the lowest concentration, inject the standard solution three times into the HPLC. Keep the

injection volume as well as the other parameters of the calibration and the sample measurement constant.

The functions shall be presented as a graph in a diagram. To achieve this, plot the measurement values A

(peak areas in the units of the integration systems) for each substance i on the axis as ordinates and the

corresponding mass concentrations m of substance i on the abscissa. When using an internal standard, plot

the ratios of the measurement values of A of substance i to A of the internal standard as ordinate and the

i IS

ratios of the corresponding mass concentrations of m of substance i to m of the internal standard on the

i IS
abscissa.

The basic function equation and the correlation coefficient are calculated and are part of the analytical result.

If an electronic integration system is used, the determined peak areas shall be checked for plausibility by

means of the plotted chromatogram. The measurement values shall be stored as complete raw data to enable

re-integration.
7.3 Determination of response factors and quantification

Prior to analysis, determine the response factors for the PAHs by injecting a calibration solution containing

known masses of the components of interest and the internal standard (e.g. 6-methylchrysene for FLD or

indeno[1,2,3-cd]fluoranthene for DAD) at least three times. Calculate the response factors f by comparing the

peak areas in the chromatogram and the corresponding masses of the substances according to Equation (1).

A m
IS ic
f = (1)
A m
icIS
where
f is the response factor of the ith PAH compound;

A is the area of the internal standard in the chromatogram of the calibration solution;

A is the area of the ith PAH compound in the chromatogram of the calibration solution;

m is the mass of the ith PAH compound in the calibration solution;
m is the mass of the internal standard in the calibration solution.

The average values of the response factors for the three injections can be used for further analysis.

Quantitative determination of the PAH compounds in the sample extracts is performed by the internal

standard method. Before sample preparation, add a known mass of the internal standard (e.g.

6-methylcrysene in the case of FLD or indeno[1,2,3-cd]fluoranthene in the case of DAD) to the sample. This

should be equivalent to three to five times the mass of benzo[a]pyrene. A guide value which may be used as a

3 3
basis is 1 ng/m to 10 ng/m of benzo[a]pyrene in the sample.

Calculate the masses of the PAH compounds in the sample extracts according to Equation (2).

fA m
iiEISE
m = (2)
ISE
© ISO 2005 – All rights reserved 7
---------------------- Page: 12 ----------------------
ISO 16362:2005(E)
where

A is the area of the internal standard in the chromatogram of the sample extract;

ISE
m is the mass of the internal standard in the sample extract;
ISE
A is the area of the ith PAH compound in the chromatogram of the sample extract;
i E
m is the mass of the ith PAH compound in the sample extract.
i E

For verification of the analytical procedure, at the beginning of an analytical series and at an interval of 10 to

15 samples, carry out a control analysis using calibration solutions.

To calibrate the overall determination procedure, place at least one aliquot of one calibration solution into a

250 ml round-bottomed flask (when the medium/high-volume sampler is used) or into a 100 ml round-bottom

flask (when the low-volume sampler is used); add thereafter 150 ml or 70 ml of toluene, respectively, and

shake the mixture. Then add the internal standard and a blank filter and prepare the mixture in accordance

with 6.2. All apparatus, solvents and operating steps which are normally employed in the analysis of the

samples shall be included. The deviations of the response factors f, that are obtained on calibrating the

overall measurement procedure, shall not differ from each other by more than 10 %. If the differences are

greater, the system shall be checked. After the reason has been found carry out a complete recalibration.

The measurement procedure shall be calibrated with a multi-component calibration standard solution

(see 5.1.5) in which the analyte is included. The calibration function has to be linear for the range of the

complete measurement procedure.

In the context of this International Standard, the complete measurement procedure comprises all steps

beginning with the filter preparation. It is not possible to include sampling into the calibration step.

The linear range shall be determined over a range of at least 5 different concentrations. The calibration

function determined for a substance is only valid for the calibrated concentration range. Furthermore, the

calibration function depends on the operating conditions of the chromatographic systems and shall be

checked regularly. For routine measurements it is sufficient to adjust the calibration function by a one-point-

check.

The calibration with standard solutions of different concentrations within the linear range of the detector gives

information about performance characteristics. Generally, the signal of the compound

...

SLOVENSKI STANDARD
SIST ISO 16362:2005
01-december-2005
=XQDQML]UDN'RORþHYDQMHSROLFLNOLþQLKDURPDWVNLKRJOMLNRYRGLNRYYGHOFLKV
WHNRþLQVNRNURPDWRJUDILMRYLVRNHORþOMLYRVWL

Ambient air - Determination of particle-phase polycyclic aromatic hydrocarbons by high

performance liquid chromatography

Air ambiant - Détermination des particules d'hydrocarbures aromatiques polycycliques

par chromatographie liquide à haute performance
Ta slovenski standard je istoveten z: ISO 16362:2005
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
SIST ISO 16362:2005 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST ISO 16362:2005
---------------------- Page: 2 ----------------------
SIST ISO 16362:2005
INTERNATIONAL ISO
STANDARD 16362
First edition
2005-02-15
Ambient air — Determination of particle-
phase polycyclic aromatic hydrocarbons
by high performance liquid
chromatography
Air ambiant — Détermination des particules d'hydrocarbures
aromatiques polycycliques par chromatographie liquide à haute
performance
Reference number
ISO 16362:2005(E)
ISO 2005
---------------------- Page: 3 ----------------------
SIST ISO 16362:2005
ISO 16362:2005(E)
PDF disclaimer

This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but

shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In

downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat

accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.

Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation

parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In

the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

© ISO 2005

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or

ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2005 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 16362:2005
ISO 16362:2005(E)
Contents Page

Foreword............................................................................................................................................................ iv

Introduction ........................................................................................................................................................ v

1 Scope...................................................................................................................................................... 1

2 Terms and definitions........................................................................................................................... 1

3 Symbols and abbreviated terms.......................................................................................................... 2

3.1 Symbols ................................................................................................................................................. 2

3.2 Abbreviated terms................................................................................................................................. 2

4 Principle of the procedure.................................................................................................................... 2

5 Reagents, apparatus and materials .................................................................................................... 2

6 Measurement procedure ...................................................................................................................... 5

6.1 Sampling ................................................................................................................................................ 5

6.2 Sample preparation............................................................................................................................... 5

6.3 HPLC analysis ....................................................................................................................................... 6

7 Establishment of the calibration function and verification of the measurement values............... 6

7.1 Identification.......................................................................................................................................... 6

7.2 Instrument calibration .......................................................................................................................... 7

7.3 Determination of response factors and quantification ..................................................................... 7

7.4 Determination of the extraction efficiency ......................................................................................... 9

8 Calculation of the result ....................................................................................................................... 9

9 Performance characteristics................................................................................................................ 9

9.1 Standard deviations of the overall measurement procedure........................................................... 9

9.2 Detection limits ..................................................................................................................................... 9

10 Interferences........................................................................................................................................ 11

11 Quality assurance ............................................................................................................................... 11

12 Test report............................................................................................................................................ 12

Annex A (informative) General information ................................................................................................... 13

Annex B (informative) Examples of operation parameters for HPLC analysis with FLD and DAD in

series.................................................................................................................................................... 14

Annex C (informative) Extraction efficiencies for some PAH compounds................................................. 17

Annex D (informative) Results of duplicate measurements......................................................................... 18

Annex E (informative) Comparison measurements and invariance test of the PAH profiles................... 20

Annex F (informative) Physical constants of PAHs ...................................................................................... 21

Annex G (informative) List of HPLC columns................................................................................................ 25

Bibliography ..................................................................................................................................................... 26

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SIST ISO 16362:2005
ISO 16362:2005(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 16362 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 3, Ambient

atmospheres.
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Introduction

Several polycyclic aromatic hydrocarbons (PAHs) are considered to be potential human carcinogens. PAHs

are emitted into the atmosphere primarily through combustion of fossil fuel and wood. Two- and three-ring

PAHs are typically present in urban air at concentrations ranging from ten to several hundred nanograms per

cubic metre (ng/m ); those with four or more rings are usually found at concentrations of a few nanograms per

cubic metre or lower. PAHs possess saturation vapour pressures at 25 °C that range from 10 kPa to less

−13 −8

than 10 kPa. Those with vapour pressures above 10 kPa may be substantially distributed between the

gas phase and particle-associated (particulate) phase in the atmosphere. The distribution between phases

depends on ambient temperature, humidity, types and concentrations of PAHs and particulate matter, and

residence time in the air. PAHs, especially those having vapour pressures above 10 kPa, tend to vaporize

from particle filters during sampling.

This International Standard allows the determination of low volatility, particle-bound PAHs, in contrast to

[1]

ISO 12884 which allows the measurement of PAHs in the gas phase. This International Standard allows the

use of a range of sampler flowrates, and requires the use of high performance liquid chromatography (HPLC)

with the detection carried out by either fluorescence detection or UV absorption.

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SIST ISO 16362:2005
INTERNATIONAL STANDARD ISO 16362:2005(E)
Ambient air — Determination of particle-phase polycyclic
aromatic hydrocarbons by high performance liquid
chromatography
1 Scope

This International Standard specifies sampling, clean-up and analysis procedures for the quantitative

determination of low volatility (particle-bound) polycyclic aromatic hydrocarbons (PAHs) in ambient air. For

sampling, a low-volume or a medium/high-volume sampling device may be used. Sampling times between 1 h

3 3

and 24 h are possible. The sampling volume flowrates can range from 1 m /h to 4 m /h (“low volume

3 3

sampler”) or from 10 m /h to about 90 m /h (“medium/high-volume sampler”). In any case, the linear face

velocity at the collection filter should range between about 0,5 m/s and 0,9 m/s.

The method has been validated for sampling periods up to 24 h. The detection limits for single PAHs and the

standard deviations resulting from duplicate measurements are listed in 9.2 and Annex D respectively.

This International Standard describes a sampling and analysis procedure for PAH that involves collection from

air onto a filter followed by analysis using high performance liquid chromatography usually with fluorescence

detector (FLD). The use of a diode array detector (DAD) is possible. The combination of both detector types is

also possible (see Annex B). Total suspended particulate matter is sampled.

Generally, compounds having a boiling point above 430 °C (vapour pressure less than 10 kPa at 25 °C, e.g.

chrysene, benz[a]anthracene) can be collected efficiently on the filter at low ambient temperatures (e.g. below

[1]

10 °C). In contrast, at higher temperatures (above 30 °C, see also ISO 12884 ), only PAHs having boiling

−10

points above 475 °C (vapour pressure less than 10 kPa at 25 °C) are determined quantitatively

(see Annex F).
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
blank value solution

solution which contains the chemicals used in making up the sample solution batch and the constituents

influencing the measurement in the same or similar concentration as the sample to be analysed, but to which

the compound to be determined has expressly not been added
2.2
low-volume sampling device
3 3
sampling device with a volume flowrate of 1 m /h to 4 m /h
2.3
medium/high-volume sampling device
3 3
sampling device with a volume flowrate of 10 m /h to about 90 m /h
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3 Symbols and abbreviated terms
3.1 Symbols
A peak area of component i
A peak area of internal standard
ρ mass concentration
f response factors, slope of straight line
m mass of component i
m mass of internal standard
M relative molecular mass (molecular weight)
V volume
3.2 Abbreviated terms
ASE accelerated solvent extraction
b.p. boiling point
DAD diode array detector (UV absorption)
FLD fluorescence detector
HPLC high performance liquid chromatography
PAH polycyclic aromatic hydrocarbon
SOP standard operating procedure
UV ultraviolet
WHO World Health Organization
4 Principle of the procedure
3 3

For sampling, sampling devices with volume flowrates from 1 m /h to about 90 m /h may be used. The

particulate matter, onto which the PAHs are adsorbed, is collected on glass or quartz fibre filters.

The PAHs are extracted and the extract concentrated. If necessary, the extracts may be cleaned by column

chromatography using silica gel.

The PAHs are determined by HPLC using DAD or FLD. For quality assurance, internal standards are added.

5 Reagents, apparatus and materials
5.1 Reagents

5.1.1 Solvents for analysis: water, acetonitrile, toluene (all solvents of chromatographic grade).

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5.1.2 Solvents for sample preparation: chromatographic grade toluene, cyclohexane and acetonitrile.

The chromatograms of the solvents obtained under the conditions of the illustrative example shall not exhibit

any interfering peaks.
5.1.3 Helium, purity 99,999 %; for degasification of solvents.

To avoid interferences, no plastic hoses shall be employed, preferably metal hoses are recommended.

5.1.4 Internal standard

If using DAD: indeno[1,2,3-cd]fluoranthene dissolved in toluene, mass concentration e.g. 3 µg/ml (see 6.2).

If using FLD: 6-methylchrysene.
5.1.5 Calibration standards
Cyclopenta[c,d]pyrene CPP
Benz[a]anthracene BaA
Chrysene CHR
Benzo[b]fluoranthene BbF
Benzo[j]fluoranthene BjF
Benzo[k]fluoranthene BkF
Benzo[a]pyrene BaP
Benzo[e]pyrene BeP
Indeno[1,2,3-cd]pyrene INP
Dibenz[a,h]anthracene DBahA
Dibenz[a,c]anthracene DBacA
Benzo[g,h,i]perylene BghiP
Anthanthrene ANT
Coronene COR
Dibenzo[a,l]pyrene DBalP
Dibenzo[a,i]pyrene DBaiP
Dibenzo[a,e]pyrene DBaeP
Dibenzo[a,h]pyrene DBahP
Benzo[a]chrysene (= picene) BaC
5.2 Apparatus

5.2.1 Sampling device, consisting of the following parts (commercially available).

5.2.1.1 Sampling head, usually containing the filter.
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5.2.1.2 Pumping system, e.g. sliding vane-pump or turbine.

5.2.1.3 Volume meter, for measuring the sample volume or a flowrate-measuring device.

5.2.1.4 Electronic or mechanical device, to establish a constant flow.
5.2.1.5 Timer, for selecting the time and duration of the sampling.
5.2.1.6 Blunt tweezers (optional), for handling the filters.
5.2.2 Sample preparation equipment

The PAH extraction (see 7.2) is carried out using ordinary laboratory equipment. This may include:

5.2.2.1 Flasks/reflux condenser, round-bottomed flask (e.g. 250 ml, or 100 ml if the small filter device is

used) with matched reflux condenser and heating bath, or
5.2.2.2 Ultrasonic bath, beaker, capacity e.g. 50 ml or 100 ml, or

5.2.2.3 Soxhlet extractor, capacity e.g. 30 ml to 50 ml, cellulose extraction thimble, round-bottomed

flask (100 ml) with reflux condenser and heating bath, or

5.2.2.4 ASE apparatus, device for extracting samples at elevated temperatures and under high pressure.

5.2.2.5 Vacuum pump, e.g. a membrane or water-jet pump.
5.2.2.6 Centrifuge, with inserts; e.g. of volume 20 ml each.

5.2.2.7 Chromatography column, internal diameter e.g. 10 mm, length 230 mm (silica gel column).

5.2.3 Analytical apparatus

5.2.3.1 High performance liquid chromatograph, fitted with an isothermal column device, solvent

purge system, gradient pump system and a FLD or DAD.

5.2.3.2 Separation columns, reverse phase-sorbent columns optimized for PAH analysis (see Annex G).

5.2.3.3 Recording equipment, work station with screen and printer/plotter for acquiring, processing,

storing and interpreting the data and the possibility of a later baseline correction.

5.2.3.4 GC microliter syringes, suitable for metering aliquots.
5.3 Materials

5.3.1 Collection filter, glass or quartz fibre filters, collection efficiency better than 99,9 % for particles

< 0,5 µm in diameter, without organic binder, appropriate for the sampling device (circular or square).

NOTE Filters coated or impregnated with polytetrafluoroethene (PTFE) have been used for collection of particle-

[2]

associated PAHs . Use of these filters, in lieu of those specified, requires validation of their performance by the user.

5.3.2 Sorbent for column chromatography

Silica gel, high purity grade, type 60, particle diameter 70 µm to 200 µm; 15 % mass fraction of water is added

24 h before use. To pack the column, a slurry is formed of 10 g of moistened silica gel in 40 ml of cyclohexane.

The slurry, freed from air bubbles by shaking, is packed into the chromatography column. Prior to use, the

cyclohexane is drawn off until the level of liquid drops to the surface of the silica gel layer.

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6 Measurement procedure
6.1 Sampling
Choose a sampling device appropriate to the measurement task.

Label each collection filter in the laboratory, and, by means of tweezers, place it into the appropriate filter

holder. Ensure that the labelling material is not extracted. Fix the filter with a supporting ring. Put the filter

holder, with the filter inserted, into a Petri dish and place it in an airtight shipping container (transport box) for

transport to the measuring site. At the measuring site, insert the filter holder containing the filter into the

sampling head, which is connected to the suction tube, and fix it.

Set the sampling time from 1 h to 24 h, depending on the sampling task. Set the pump and the timer in

operation synchronously.

If the flow-controlling device is used in combination with a total volume meter, the sample volume is derived

from the volume meter readings at the beginning and the end of the sampling period.

If the flow-controlling device is combined with a flowrate-measuring device, the sample volume is derived from

the average flowrate (calculated from the flowrates at the least at the beginning and end of the measurement

period) and the elapsed time.

The flowrate-measuring device should also be used to check proper operation of the flow-controlling device at

the beginning and end of the sampling period.

Turn the pump off after sampling. Remove the filter holder with the exposed filter from the sampling head. Put

the filter holder containing the filter again into a Petri dish and place it in an airtight shipping container

(transport box) with the exposed filter side facing upwards for transport. Transport the shipping container

(transport box) horizontally. In the laboratory, remove the exposed filter from the filter holder with the aid of

tweezers.

Prior to extraction, store the filter in the dark at ambient temperature or below.

At least 10 % of the samples, or a minimum of one per sampling site if fewer than 10 samples are taken at the

site, shall be field blanks.
6.2 Sample preparation

Check the purity of the filters and glassware and the purity of the solvents and reagents. For this purpose, add

the internal standard solution to an unexposed filter and subject it to the entire analytical procedure (blank

value).

The blank values are not taken into account in the calculation, but shall not exceed 10 % of the value of the

sample or 10 % of a limit/guide value to be monitored.

Protect the samples and sample solutions against direct light during preparation.

For the extraction, place the filter in a 250 ml round-bottomed flask, cover it with 150 ml of toluene (or 70 ml of

toluene in a 100 ml round-bottomed flask if small filters are used) and add then 50 µl of the internal standard

[3]

solution (see 5.2.2.3). Toluene is especially suitable for the extraction of PAHs . If other solvents (e.g.

dichloromethane, acetonitrile) are used, the procedure shall have been validated using NIST standards. Insert

the reflux condenser and heat the contents of the flask to boiling for about 20 min. Separate the extract from

the filter material and dust particles by filtration.
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The extraction may also be performed quantitatively by various other methods:
 in a Soxhlet apparatus (toluene: 8 h, at least 10 cycles per hour);
 in the ultrasonic bath in a beaker (toluene: at least 15 min);

 in an ultrasonic bath followed by centrifugation. The filter is cut into pieces and placed in centrifuge tube,

followed by the addition of 15 ml toluene. The tubes are placed in the bath and extracted for 15 min. They

are then centrifuged (10 min, 3 000 r/min) and the solvent is decanted. The whole extraction procedure is

repeated. Both extraction solvents are combined;

 by accelerated solvent extraction (ASE). The filter is placed in the extraction vessel and extracted at a

temperature of 150 °C with toluene.
All methods shall be validated.

Concentrate the toluene solution to few microlitres under reduced pressure (e.g. 13 kPa). Keep this

evaporation step under observation at all times.

NOTE If evaporation is continued to dryness and the residue allowed to remain for a time in a vacuum, some PAHs

could be lost.
If further clean-up is necessary, add 2 ml of cyclohexane.

Add the cyclohexane solution to the pre-prepared silica gel column (see 5.2.2.7) using a syringe. Rinse the

flask then with 2 ml of cyclohexane which is also added with a syringe to the silica gel column. Carry out the

elution using 100 ml of cyclohexane. To remove the cyclohexane, concentrate the eluate to a volume of a few

milliliters and evaporate it then under a nitrogen stream almost to dryness. Dissolve the residue then in the

correct solvent for injection into the HPLC column, e.g. 100 µl of acetonitrile.

NOTE If the origin of the air sample is known and interferents are low, the clean-up using a silica gel column may be

unnecessary.

If the extract is not analysed immediately, it shall be stored in a refrigerator. Before analysis, it is allowed to

warm to room temperature.
6.3 HPLC analysis
Inject an aliquot of the sample (e.g. 20 µl) into the HPLC apparatus.

An example of operation conditions for HPLC analysis with FLD and DAD in series is given in Annex B.

7 Establishment of the calibration function and verification of the measurement
values
7.1 Identification

The separation conditions are optimized with aid of multi-component calibration standard solutions (see 5.1.5),

which gives adequate separation of the compounds of interest.

A component in the sample is primarily identified by comparison of its retention time to that of the same

substance in the calibration solution analysed under identical conditions. The level of identity shall be reported.

The concentrations of the calibration standards should be in the range of (depending on the measurement

task):
 2 ng/ml to 200 ng/ml, when a FLD is used;
 20 ng/ml to 1 000 ng/ml, when a DAD is used.
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7.2 Instrument calibration

Prepare calibration standard solutions of different concentrations for each new substance i to be determined

using acetonitrile. The calibration does not include the overall measurement procedure. Handle the calibration

standard solutions identically to the sample solutions.

Starting with the lowest concentration, inject the standard solution three times into the HPLC. Keep the

injection volume as well as the other parameters of the calibration and the sample measurement constant.

The functions shall be presented as a graph in a diagram. To achieve this, plot the measurement values A

(peak areas in the units of the integration systems) for each substance i on the axis as ordinates and the

corresponding mass concentrations m of substance i on the abscissa. When using an internal standard, plot

the ratios of the measurement values of A of substance i to A of the internal standard as ordinate and the

i IS

ratios of the corresponding mass concentrations of m of substance i to m of the internal standard on the

i IS
abscissa.

The basic function equation and the correlation coefficient are calculated and are part of the analytical result.

If an electronic integration system is used, the determined peak areas shall be checked for plausibility by

means of the plotted chromatogram. The measurement values shall be stored as complete raw data to enable

re-integration.
7.3 Determination of response factors and quantification

Prior to analysis, determine the response factors for the PAHs by injecting a calibration solution containing

known masses of the components of interest and the internal standard (e.g. 6-methylchrysene for FLD or

indeno[1,2,3-cd]fluoranthene for DAD) at least three times. Calculate the response factors f by comparing the

peak areas in the chromatogram and the corresponding masses of the substances according to Equation (1).

A m
IS ic
f = (1)
A m
icIS
where
f is the response factor of the ith PAH compound;

A is the area of the internal standard in the chromatogram of the calibration solution;

A is the area of the ith PAH compound in the chromatogram of the calibration solution;

m is the mass of the ith PAH compound in the calibration solution;
m is the mass of the internal standard in the calibration solution.

The average values of the response factors for the three injections can be used for further analysis.

Quantitative determination of the PAH compounds in the sample extracts is performed by the internal

standard method. Before sample preparation, add a known mass of the internal standard (e.g.

6-methylcrysene in the case of FLD or indeno[1,2,3-cd]fluoranthene in the case of DAD) to the sample. This

should be equivalent to three to five times the mass of benzo[a]pyrene. A guide value which may be used as a

3 3
basis is 1 ng/m to 10 ng/m of benzo[a]pyrene in the sample.

Calculate the masses of the PAH compounds in the sample extracts according to Equation (2).

fA m
iiEISE
m = (2)
ISE
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where

A is the area of the internal standard in the chromatogram of the sample extract;

ISE
m is the mass of the internal standard in the sample extract;
ISE
A is the area of the ith PAH compound in the chromatogram of the sample extract;
i E
m is the mass of the ith PAH compound in the sample extract.
i E

For verification of the analytical procedure, at the beginning of an analytical series and at an interval of 10 to

15 samples, carry out a control analysis using calibration solutions.

To calibrate the overall determination procedure, place at least one aliquot of one calibration solution into a

250 ml round-bottomed flask (when the medium/high-volume sampler is used) or into a 100 ml round-bottom

flask (when the low-volume sampler is used); add thereafter 150 ml or 70 ml of toluene, respectively, and

shake the mixture. Then add the internal standard and a blank filter and prepare the mixture in accordance

with 6.2. All apparatus, solvents and operating steps which are normally employed in the analysis of the

samples shall be included. The deviations of the response factors f, that are obtained on calibrating the

overall measurement procedure, shall not differ from each other by more than 10 %. If the differences are

greater
...

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