SIST EN ISO 17234-1:2020

Leather - Chemical tests for the determination of certain azo colorants in dyed leathers - Part 1: Determination of certain aromatic amines derived from azo colorants (ISO 17234-1:2020)

This document specifies a method for determining the use of certain azo colourants which can release
certain aromatic amines.

Leder - Chemische Prüfungen zur Bestimmung bestimmter Azofarbstoffe in gefärbten Ledern - Teil 1: Bestimmung bestimmter aromatischer Amine aus Azofarbstoffen (ISO 17234-1:2020)

Dieses Dokument legt ein Verfahren zur Bestimmung der Verwendung bestimmter Azofarbstoffe fest, die bestimmte aromatische Amine freisetzen können.

Cuir - Essais chimiques pour le dosage de certains colorants azoïques dans les cuirs teints - Partie 1: Dosage de certaines amines aromatiques dérivées des colorants azoïques (ISO 17234-1:2020)

Le présent document spécifie une méthode permettant de déterminer l'utilisation de certains colorants azoïques qui peuvent libérer certaines amines aromatiques.

Usnje - Kemijski preskusi za določevanje nekaterih azo barvil na barvanem usnju - 1. del: Določevanje nekaterih aromatskih aminov, izvirajočih iz azo barvil (ISO 17234-1:2020)

General Information

• Status: Published
• Public Enquiry End Date: 02-Jun-2019
• Publication Date: 05-Oct-2020
• ICS: 59.140.30 - Leather and furs
• ICS: 71.040.40 - Chemical analysis
• Technical Committee: IUSN - Leather
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 30-Sep-2020
• Due Date: 05-Dec-2020
• Completion Date: 06-Oct-2020
• Ref Project: EN ISO 17234-1:2020 - Leather - Chemical tests for the determination of certain azo colourants in dyed leathers - Part 1: Determination of certain aromatic amines derived from azo colorants (ISO 17234-1:2020)

RELATIONS

• Replaces: SIST EN ISO 17234-1:2015 - Leather - Chemical tests for the determination of certain azo colorants in dyed leathers - Part 1: Determination of certain aromatic amines derived from azo colorants (ISO 17234-1:2015)
• Effective Date: 01-Nov-2020

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN ISO 17234-1:2020
01-november-2020
Nadomešča:
SIST EN ISO 17234-1:2015

Usnje - Kemijski preskusi za določevanje nekaterih azo barvil na barvanem usnju -

1. del: Določevanje nekaterih aromatskih aminov, izvirajočih iz azo barvil (ISO
17234-1:2020)

Leather - Chemical tests for the determination of certain azo colorants in dyed leathers -

Part 1: Determination of certain aromatic amines derived from azo colorants (ISO 17234-

1:2020)
Leder - Chemische Prüfungen zur Bestimmung bestimmter Azofarbstoffe in gefärbten

Ledern - Teil 1: Bestimmung bestimmter aromatischer Amine aus Azofarbstoffen (ISO

17234-1:2020)

Cuir - Essais chimiques pour le dosage de certains colorants azoïques dans les cuirs

teints - Partie 1: Dosage de certaines amines aromatiques dérivées des colorants
azoïques (ISO 17234-1:2020)
Ta slovenski standard je istoveten z: EN ISO 17234-1:2020
ICS:
59.140.30 Usnje in krzno Leather and furs
71.040.40 Kemijska analiza Chemical analysis
SIST EN ISO 17234-1:2020 en,fr,de

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

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SIST EN ISO 17234-1:2020
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SIST EN ISO 17234-1:2020
EN ISO 17234-1
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2020
EUROPÄISCHE NORM
ICS 59.140.30 Supersedes EN ISO 17234-1:2015
English Version
Leather - Chemical tests for the determination of certain
azo colorants in dyed leathers - Part 1: Determination of
certain aromatic amines derived from azo colorants (ISO
17234-1:2020)

Cuir - Essais chimiques pour le dosage de certains Leder - Chemische Prüfungen zur Bestimmung

colorants azoïques dans les cuirs teints - Partie 1: bestimmter Azofarbstoffe in gefärbten Ledern - Teil 1:

Dosage de certaines amines aromatiques dérivées des Bestimmung bestimmter aromatischer Amine aus

colorants azoïques (ISO 17234-1:2020) Azofarbstoffen (ISO 17234-1:2020)
This European Standard was approved by CEN on 27 July 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17234-1:2020 E

worldwide for CEN national Members.
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SIST EN ISO 17234-1:2020
EN ISO 17234-1:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 17234-1:2020
EN ISO 17234-1:2020 (E)
European foreword

This document (EN ISO 17234-1:2020) has been prepared by Technical Committee ISO/IULTCS

"International Union of Leather Technologists and Chemists Societies" in collaboration with Technical

Committee CEN/TC 289 “Leather” the secretariat of which is held by UNI.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by March 2021, and conflicting national standards shall

be withdrawn at the latest by March 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 17234-1:2015.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 17234-1:2020 has been approved by CEN as EN ISO 17234-1:2020 without any

modification.
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SIST EN ISO 17234-1:2020
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SIST EN ISO 17234-1:2020
INTERNATIONAL ISO
STANDARD 17234-1
IULTCS
IUC 20-1
Third edition
2020-08
Leather — Chemical tests for
the determination of certain azo
colourants in dyed leathers —
Part 1:
Determination of certain aromatic
amines derived from azo colourants
Cuir — Essais chimiques pour le dosage de certains colorants
azoïques dans les cuirs teints —
Partie 1: Dosage de certaines amines aromatiques dérivées des
colorants azoïques
Reference numbers
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)
ISO 2020
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

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]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)
Contents Page

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

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

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 General ............................................................................................................................................................................................................................ 1

5 Principle ........................................................................................................................................................................................................................ 3

6 Safety precautions .............................................................................................................................................................................................. 3

7 Apparatus ..................................................................................................................................................................................................................... 3

8 Reagents ........................................................................................................................................................................................................................ 4

9 Sampling and preparation of samples ........................................................................................................................................... 5

10 Procedure..................................................................................................................................................................................................................... 5

10.1 Degreasing .................................................................................................................................................................................................. 5

10.2 Reductive cleavage ............................................................................................................................................................................... 5

10.3 Liquid-liquid extraction .................................................................................................................................................................. 5

10.4 Check of the analytical system ................................................................................................................................................... 6

11 Chromatographic analyses ......................................................................................................................................................................... 6

12 Calibration .................................................................................................................................................................................................................. 6

13 Evaluation .................................................................................................................................................................................................................... 6

13.1 Calculation of amine in the sample ....................................................................................................................................... 6

13.2 Reliability of the method ................................................................................................................................................................ 7

14 Test report ................................................................................................................................................................................................................... 7

Annex A (informative) Chromatographic analyses ................................................................................................................................ 9

Annex B (informative) Reliability of the method ..................................................................................................................................13

Annex C (informative) Assessment guide — Interpretation of analytical results ..............................................14

Annex D (informative) Procedure for liquid/liquid extraction without diatomaceous earth ..............20

Bibliography .............................................................................................................................................................................................................................23

© ISO 2020 – All rights reserved iii
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(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 of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

This document was prepared by the Chemical Test Commission of the International Union of Leather

Technologists and Chemists Societies (IUC Commission, IULTCS) in collaboration with the European

Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, the secretariat of

which is held by UNI, in accordance with the Agreement on technical cooperation between ISO and CEN

(Vienna Agreement). This method is technically similar to the method in IUC 20, which was declared an

official method at the IULTCS Delegates meeting on 31st May 2003 in Cancun, Mexico.

IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to

further the advancement of leather science and technology. IULTCS has three Commissions, which

are responsible for establishing international methods for the sampling and testing of leather. ISO

recognizes IULTCS as an international standardizing body for the preparation of test methods for

leather.

This third edition cancels and replaces the second edition (ISO 17234-1:2015), which has been

technically revised.
The main changes to the previous edition are as follows:
— a new Clause 3 added;
— technical changes to Clause 7 and Clause 8;
— changes to Clause 9 and Clause 10 to improve the method;

— Annex C expanded to give examples of false-positive results, suggested procedures and suggested

comments in the test report;
— a new informative Annex D added.
A list of all parts in the ISO 17234 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
INTERNATIONAL STANDARD
IULTCS/IUC 20-1:2020(E)
Leather — Chemical tests for the determination of certain
azo colourants in dyed leathers —
Part 1:
Determination of certain aromatic amines derived from
azo colourants
1 Scope

This document specifies a method for determining the use of certain azo colourants which can release

certain aromatic amines.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 2418, Leather — Chemical, physical and mechanical and fastness tests — Sampling location

ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 4044, Leather — Chemical tests — Preparation of chemical test samples

ISO 17234-2, Leather — Chemical tests for the determination of certain azo colorants in dyed leathers —

Part 2: Determination of 4-aminoazobenzene
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/
4 General

Certain azo colourants can release, by reductive cleavage of azo group(s), one or more of the aromatic

[2] [3]

amines listed in EU Regulation 1907/2006, Annex XVII, Appendix 8 and GB 20400-2006 (see Table 1).

© ISO 2020 – All rights reserved 1
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)
[2]

Table 1 — Aromatic amines listed in EU Regulation 1907/2006, Annex XVII, Appendix 8 and

[3]
GB 20400-2006
No. CAS number Index number EC number Substances
1 92–67–1 612–072–00–6 202–177–1 biphenyl-4-ylamine
4-aminobiphenyl
xenylamine
2 92–87–5 612–042–00–2 202–199–1 benzidine
3 95–69–2 612–196–00–0 202–441–6 4-chloro-o-toluidine
4 91–59–8 612–022–00–3 202–080–4 2-naphthylamine
5 97–56–3 611–006–00–3 202–591–2 o-aminoazotoluene
4-amino-2',3-dimethylazobenzene
4-o-tolylazo-o-toluidine
6 99–55–8 612–210–00–5 202–765–8 5-nitro-o-toluidine
2-amino-4-nitrotoluene
7 106–47–8 612–137–00–9 203–401–0 4-chloroaniline
8 615–05–4 612–200–00–0 210–406–1 4-methoxy-m-phenylenediamine
2,4-diaminoanisole
9 101–77–9 612–051–00–1 202–974–4 4,4'-methylenedianiline
4,4'-diaminodiphenylmethane
10 91–94–1 612–068–00–4 202–109–0 3,3'-dichlorobenzidine
3,3'-dichlorobiphenyl-4,4'-ylenediamine
11 119–90–4 612–036–00-X 204–355–4 3,3'-dimethoxybenzidine
o-dianisidine
12 119–93–7 612–041–00–7 204–358–0 3,3'-dimethylbenzidine
4,4'-bi-o-toluidine
13 838–88–0 612–085–00–7 212–658–8 4,4'-methylenedi-o-toluidine
14 120–71–8 612–209–00–X 204–419–1 6-methoxy-m-toluidine
p-cresidine
15 101–14–4 612–078–00–9 202–918–9 4,4'-methylene-bis-(2-chloro-aniline)
2,2'-dichloro-4.4’-methylene-dianiline
16 101–80–4 612–199–00–7 202–977–0 4,4'-oxydianiline
17 139–65–1 612–198–00–1 205–370–9 4,4'-thiodianiline
18 95–53–4 612–091–00-X 202–429–0 o-toluidine
2-aminotoluene
19 95–80–7 612–099–00–3 202–453–1 4-methyl-m-phenylenediamine
2,4-toluylendiamine
2,4-diaminotoluene
20 137–17–7 612–197–00–6 205–282–0 2,4,5-trimethylaniline
21 90–04–0 612–035–00–4 201–963–1 o-anisidine
2-methoxyaniline
22 60–09–3 611–008–00–4 200–453–6 4-aminoazobenzene
23 95–68–1 612–027–00–0 202–440–0 2,4-xylidine
2,4-dimethylbenzene-1-amine
24 87–62–7 612–161–00-X 201–758–7 2,6-xylidine
2,6-dimethylbenzene-1-amine

The CAS-numbers 97–56–3 (no. 5) and 99–55–8 (no. 6) are further reduced to CAS-numbers 95–53–4 (no. 18) and

95–80–7 (no. 19).

Azo colourants that are able to form 4-aminoazobenzene generate under the condition of this method aniline CAS-

number 62–53–3) and 1,4-phenylenediamine (CAS number 106–50–3). The presence of these colourants shall be tested

using ISO 17234-2.
Additional aromatic amines in GB 20400–2006.
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)
5 Principle

After degreasing, the leather sample is treated with sodium dithionite in an aqueous buffer solution

(pH 6) at 70 °C in a closed vessel. The amines released in the process of reductive cleavage are transferred

to a t-butyl methyl ether (8.5) phase by means of liquid-liquid extraction using diatomaceous earth

columns. The t-butyl methyl ether (8.5) extract is then concentrated under mild conditions in a rotary

vacuum evaporator and the residue is dissolved in a suitable solvent, depending on the method used to

determine the amines (see Annex A).

Determination of the amines is performed by means of high-performance liquid chromatography

(HPLC) using a diode array detector (DAD) or mass selective detector (HPLC-MS), capillary gas

chromatography with a mass selective detector (GC-MS) or by capillary electrophoresis with a diode

array detector (CE-DAD), or qualitatively with thin layer chromatography (TLC, HPTLC).

The amines shall be identified by means of at least two different chromatographic separation methods

in order to avoid any possible misinterpretations caused by interfering substances (such as position

isomers of the amines to be identified) and hence any incorrect statements. Amine quantification shall

be performed by HPLC-DAD or GC-MS.

A screening method using liquid-liquid extraction without diatomaceous earth columns is described in

Annex D.
6 Safety precautions

WARNING — The aromatic amines listed in Clause 4 are classified as substances known to be or

suspected to be human carcinogens.

6.1 It is the user's responsibility to use safe and proper techniques when handling materials in this

test method. Consult manufacturers for specific details, such as material safety data sheets and other

recommendations.

6.2 Good laboratory practice should be followed. Wear safety glasses in all laboratory areas and a dust

respirator and single-use gloves while handling powder colourants and aromatic amines.

6.3 National and local safety regulations can apply.
7 Apparatus
The usual laboratory equipment and, in particular, the following:

7.1 Suitable reaction vessel, of temperature-resistant glass with a gas-tight closure.

7.2 Suitable heating system, at (70 ± 2) °C.

7.3 Polypropylene or glass column, inside diameter 25 mm to 30 mm, length 130 mm to 150 mm,

packed with 20 g of diatomaceous earth, fitted with glass fibre filter at the outlet.

The diatomaceous earth columns are either bought pre-packed and used as is, or 20 g of diatomaceous

earth can be packed into a glass or polypropylene column of the dimensions given.

7.4 Vacuum rotary evaporator with vacuum control and water bath.
7.5 Pipettes, in required sizes or variables pipettes.
7.6 Ultrasonic bath with thermostat.
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)
7.7 Chromatographic equipment, selected from the following:
7.7.1 High-performance liquid chromatography (HPLC) and DAD or MS.
7.7.2 Capillary gas chromatography (GC), with MS.
7.7.3 Capillary electrophoresis (CE), with DAD.

7.7.4 Thin layer chromatography (TLC) or high-performance thin layer chromatography

(HPTLC).
NOTE A description of the chromatographic equipment (7.7) is given in Annex A.
8 Reagents
Unless otherwise specified, analytical grade chemicals shall be used.
8.1 n-hexane.
8.2 Citrate buffer solution, 0,06 mol/l, pH = 6, preheated to (70 ± 2) °C.

8.3 Aqueous sodium dithionite solution, ρ = 200 mg/ml , freshly prepared, to be used immediately

after resting for 1 h in a closed vessel.
8.4 Sodium hydroxide aqueous solution, a mass fraction of 40 %.
8.5 t-butyl methyl ether.
8.6 Methanol.
8.7 Acetonitrile.
8.8 Amines, listed in Table 1 (highest available purity standard).
8.9 Standard solutions.
8.9.1 Stock solution of the amines (8.8), 400 µg/ml in ethyl acetate for TLC.

8.9.2 Stock solution of the amines (8.8), 200 µg/ml of each amine in an appropriate solvent.

NOTE Acetonitrile is an appropriate solvent for this stock solution, resulting in good stability of amines.

8.9.3 Standard solution for amine process control, 30 µg amine per millilitre solvent, freshly

prepared from stock solutions (8.9.1 or 8.9.2) depending on the analytical method

8.9.4 Internal standard in solution (IS), ρ = 10 μg of IS/ml of t-butyl methyl ether (8.5).

In the case of GC-MS analysis, one of the following internal standards can be used:

— IS1: naphthalene-d8, CAS no.: 1146-65-2;
— IS2: 2,4,5-trichloroaniline (TCA), CAS no.: 636-30-6;
1) ρ = mass concentration.
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)
— IS3: anthracene-d10, CAS no.: 1719-06-8.
8.10 Water, Grade 3 according to ISO 3696.
9 Sampling and preparation of samples

The leather shall be sampled in accordance with ISO 2418 and prepared in accordance with ISO 4044. If

sampling in accordance with ISO 2418 is not possible (e.g. in the case of leathers from finished products

such as shoes or garments), details about sampling shall be given in the test report. Any traces of

adhesives shall be removed mechanically.

In the case of leather patchwork fabrics with varicoloured patterns, the various colours shall be taken

into account separately as far as possible. For commodities consisting of various leather qualities,

specimens of the various qualities shall be analysed separately.

For the analytical procedure, accurately weigh a representative sample of 1,0 g of this leather sample in

the reaction vessel (7.1).
10 Procedure
10.1 Degreasing

Treat 1,0 g of the leather in a closed 50 ml vessel (7.1) with 40 ml n-hexane (8.1) in an ultrasonic bath

(7.6) at (40 ± 2) °C for 40 min.

Decant the n-hexane layer from the leather sample. Any loss of leather particles during decanting shall

be avoided. Evaporate the residual n-hexane at least overnight in the open vessel.

10.2 Reductive cleavage

Add a quantity of 15 ml buffer solution (8.9) preheated to (70 ± 2) °C to the sample.

Close the reaction vessel tightly and treat for (30 ± 1) min at (70 ± 2) °C.

Subsequently, add 3 ml aqueous sodium dithionite solution (8.3) for the reductive cleavage of the azo

groups to the reaction vessel, then shake vigorously and immediately keep at (70 ± 2) °C for another

(30 ± 1) min. Then cool to room temperature (20 °C to 25 °C) within 2 min with a cooling mixture of ice,

water and salt.
10.3 Liquid-liquid extraction

Add 1,5 ml of the NaOH solution (8.4) to the reaction solution and shake vigorously. Transfer the reaction

solution to the diatomaceous earth column (7.3) and allow it to be absorbed by the column for 15 min.

Meanwhile, add 10 ml t-butyl methyl ether (8.5) to the reaction vessel and shake vigorously. After the

15 min period decant the t-butyl methyl ether (8.5) onto the top of the column and collect the eluate in

a 250 ml round-bottom flask.

Rinse the reaction vessel with 10 ml t-butyl methyl ether (8.5) and transfer the solvent to the column.

Subsequently, pour 60 ml t-butyl methyl ether (8.5) directly onto the column.

For amine detection and quantification, the t-butyl methyl ether extract is concentrated to a volume

less than 5 ml (not to dryness) with a vacuum rotary at a temperature less than 50 °C and a pressure

of approximately 450 mbar. If it is necessary to change to another solvent, remove the remainder of the

solvent very carefully by means of a weak flow of inert gas.

NOTE 1 Removal of the solvent (concentration in the rotary vacuum evaporator, evaporation to dryness) can

lead to substantial amine losses if performed under uncontrolled conditions.
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SIST EN ISO 17234-1:2020
ISO 17234-1:2020(E)
IULTCS/IUC 20-1:2020(E)

Make up the extract or residue to 2,0 ml with an appropriate solvent for detection and determination

of the amines using chromatography [acetonitrile (8.7), t-butyl methyl ether (8.5) or methanol (8.6)]

without delay. If the complete analysis cannot be performed within (24 ± 1) h, keep the extract at

(−18 ± 3) °C and warm carefully to room temperature before analysis.

NOTE 2 Owing to the matrix, individual amines such as 2,4-diaminotoluene and 2,4-diaminoanisole are likely

to exhibit a very poor stability, especially in methanol. Where delays occur in the work routine, amines can be no

longer detectable by the time of instrumental measurement.
10.4 Check of the analytical system

To check the analysis procedure, add a certain quantity of amines to obtain x mg/l as final concentration

in a reaction vessel containing 15 ml of buffer solution (8.9).
Then carry out the procedure set out in 10.3.
Amine recovery rates shall conform with the following minimum requirements:
— amines nos 1 to 4, 7, 9 to 17 and 20 to 21: recovery rate 70 %;
— amine no. 8: recovery rate 20 %;
— amines nos 18, 19, 23 and 24: recovery rate 50 %;
— amines nos 5, 6 and 22, see footnotes to Table 1.
11 Chromatographic analyses

The detection of the aromatic amines can be performed using the chromatographic techniques listed

in 7.7. Other validated methods can be used. The quantification of the aromatic amines is performed

by means of HPLC-DAD, HPLC-MS or GC-MS. Where gas chromatography is used, appropriate internal

standards as described in 8.9.4 shall be employed.

If any amine is detected by one chromatographic method, then confirmation shall be made usin

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