SIST EN ISO 11337:2023

Plastics - Polyamides - Determination of ε-caprolactam and ω-laurolactam by gas chromatography (ISO 11337:2023)

This document specifies a method for determining ε‑caprolactam and ω‑laurolactam in polyamides by gas chromatography. It is applicable particularly to the determination of ε‑caprolactam in polyamide 6 and ω‑laurolactam in polyamide 12.
Two variants of the basic method are specified.
—    Method A is an extraction method with boiling methanol, and the extract is injected into a gas chromatograph.
—    Method B is a method using a solvent, and the solution is injected into a gas chromatograph.

Kunststoffe - Polyamide - Gaschromatographische Bestimmung von ε-Caprolactam und ω-Laurolactam (ISO 11337:2023)

Dieses Dokument legt ein gaschromatographisches Verfahren zur Bestimmung des ε-Caprolactamgehaltes und des ω-Laurolactamgehaltes in Polyamiden fest. Es ist besonders zur Bestimmung von ε-Caprolactam in Poly
amid6 und von ω-Laurolactam in Polyamid12 anwendbar.
Zwei Varianten des Basisverfahrens sind festgelegt.
—
VerfahrenA ist ein Extraktionsverfahren unter Anwendung von siedendem Methanol, bei dem das Extrakt in einen Gaschromatographen injiziert wird.
—
VerfahrenB ist ein Verfahren unter Anwendung eines Lösemittels, bei dem die Lösung in einen Gaschro
matographen injiziert wird.
SICHERHEITSHINWEIS— Anwender dieses Dokuments sollten mit der üblichen Laborpraxis, sofern zutreffend, vertraut sein. Dieses Dokument beabsichtigt nicht, alle mit seiner Anwendung verbunde
nen Sicherheitsprobleme, soweit solche vorhanden sind, anzusprechen. Es liegt in der Verantwortung des Anwenders, geeignete Sicherheits- und Gesundheitsschutzmaßnahmen zu treffen und zutreffende gesetzliche Beschränkungen vor der Anwendung zu bestimmen.

Plastiques - Polyamides - Détermination du ε-caprolactame et du ω-laurolactame par chromatographie en phase gazeuse (ISO 11337:2023)

Le présent document spécifie une méthode de dosage du ε-caprolactame et du ω-laurolactame dans les polyamides par chromatographie en phase gazeuse. Il convient particulièrement au dosage du ε-caprolactame dans le polyamide 6 et du ω-laurolactame dans le polyamide 12.
Deux variantes de la méthode de base sont spécifiées.
—    Méthode A, par extraction au méthanol en ébullition, où les extraits sont injectés dans un chromatographe en phase gazeuse;
—    Méthode B, utilisant un solvant, où la solution est injectée dans un chromatographe en phase gazeuse.

Polimerni materiali - Poliamidi - Določanje ε-kaprolaktama in ω-laurolaktama s plinsko kromatografijo (ISO 11337:2023)

Standard ISO 11337:2010 določa metodo za določanje epsilon-kaprolaktama in omega-laurolaktama v poliamidih s plinsko kromatografijo. Primeren je zlasti za določanje epsilon-kaprolaktama v poliamidu 6 in omega-laurolaktama v poliamidu 12. Glede na to, da plinska kromatografija ponuja širok razpon možnih pogojev, se je v praksi izkazalo, da je navedena metoda primerna.
Določeni sta dve različici osnovne metode:
Metoda A je metoda ekstrakcije z vrelim metanolom, ekstrakt pa se vbrizga v plinski kromatograf.
Metoda B je metoda z uporabo topila, raztopina pa se vbrizga v plinski kromatograf.

General Information

• Status: Published
• Public Enquiry End Date: 14-Sep-2022
• Publication Date: 20-Feb-2023
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: IPMA - Polimer materials and products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 13-Feb-2023
• Due Date: 20-Apr-2023
• Completion Date: 21-Feb-2023
• Ref Project: EN ISO 11337:2023 - Plastics - Polyamides - Determination of ε-caprolactam and ω-laurolactam by gas chromatography (ISO 11337:2023)

Relations

• Revised: SIST EN ISO 11337:2011 - Plastics - Polyamides - Determination of e-caprolactam and w-laurolactam by gas chromatography (ISO 11337:2010)
• Effective Date: 19-Jan-2023

Overview

EN ISO 11337:2023 (ISO 11337:2023) specifies gas-chromatographic methods for determining the lactam monomers ε‑caprolactam and ω‑laurolactam in polyamides. It is aimed particularly at polyamide 6 (ε‑caprolactam) and polyamide 12 (ω‑laurolactam). The third edition (2023) updates the 2010 version and is published by CEN/ISO for harmonized European and international use.

Key topics and technical requirements

• Two validated variants of the basic GC method:
  • Method A (extraction): test portion is extracted with boiling methanol; the methanol extract is injected into a gas chromatograph. An internal standard (e.g., 1‑dodecanol or isopropanol, newly allowed in 2023) is used.
  • Method B (dissolution/solvent): the sample is dissolved in an appropriate solvent and the solution is injected into a gas chromatograph.
• Instrumentation: Gas chromatography with suitable detectors and either packed or capillary columns (both explicitly addressed in the 2023 revision).
• Sample preparation: grinding/milling to controlled particle size, sieving (reference to sieve sizes and ISO 565 for nominal openings), and use of extraction apparatus (Soxhlet‑type or vapour‑enveloping designs) where applicable.
• Calibration and internal standards: procedures for preparing calibration and internal‑standard solutions and for peak evaluation are specified.
• Quality aspects: method precision, solvent recovery, expression of results and required test report content are included.
• Safety and conformity: users are reminded to follow normal laboratory practice and regulatory considerations.

Applications and users

Practical applications of EN ISO 11337:2023 include:

• Quality control of polyamide resins and finished components to quantify residual monomer content.
• Incoming raw‑material testing for polyamide 6 and polyamide 12 suppliers.
• Product release testing for manufacturers in automotive, electrical, consumer goods and industrial plastics sectors.
• R&D and failure analysis where residual lactam levels affect processing, mechanical properties, odour or regulatory compliance. Who will use it:
• Analytical laboratories, polymer QC labs, contract testing labs
• Polymer producers and compounders
• Material engineers and product development teams concerned with polyamide purity

Related standards

• ISO 472 - Plastics - Vocabulary (terms and definitions referenced)
• ISO 565 - Test sieves - Nominal sizes of openings (sieving requirements for sample prep)
• Published under the ISO/CEN Vienna Agreement; supersedes EN ISO 11337:2010.

Keywords: EN ISO 11337:2023, ISO 11337:2023, polyamides, ε‑caprolactam, ω‑laurolactam, gas chromatography, polyamide 6, polyamide 12, extraction method, Method A, Method B, 1‑dodecanol, isopropanol, Soxhlet.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2023
Polimerni materiali - Poliamidi - Določanje ε-kaprolaktama in ω-laurolaktama s
plinsko kromatografijo (ISO 11337:2023)
Plastics - Polyamides - Determination of ε-caprolactam and ω-laurolactam by gas
chromatography (ISO 11337:2023)
Kunststoffe - Polyamide - Gaschromatographische Bestimmung von ε-Caprolactam und
ω-Laurolactam (ISO 11337:2023)
Plastiques - Polyamides - Détermination du ε-caprolactame et du ω-laurolactame par
chromatographie en phase gazeuse (ISO 11337:2023)
Ta slovenski standard je istoveten z: EN ISO 11337:2023
ICS:
83.080.20 Plastomeri Thermoplastic materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11337
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2023
EUROPÄISCHE NORM
ICS 83.080.20 Supersedes EN ISO 11337:2010
English Version
Plastics - Polyamides - Determination of e-caprolactam
and ¿-laurolactam by gas chromatography (ISO
11337:2023)
Plastiques - Polyamides - Détermination du e- Kunststoffe - Polyamide - Gaschromatographische
caprolactame et du ¿-laurolactame par Bestimmung von e-Caprolactam und ¿-Laurolactam
chromatographie en phase gazeuse (ISO 11337:2023) (ISO 11337:2023)
This European Standard was approved by CEN on 6 January 2023.

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, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11337:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 11337:2023) has been prepared by Technical Committee ISO/TC 61 "Plastics"
in collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by
NBN.
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 August 2023, and conflicting national standards shall
be withdrawn at the latest by August 2023.
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 11337:2010.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 11337:2023 has been approved by CEN as EN ISO 11337:2023 without any modification.

INTERNATIONAL ISO
STANDARD 11337
Third edition
2023-01
Plastics — Polyamides —
Determination of ε-caprolactam and
ω-laurolactam by gas chromatography
Plastiques — Polyamides — Détermination du ε-caprolactame et du
ω-laurolactame par chromatographie en phase gazeuse
Reference number
ISO 11337:2023(E)
ISO 11337:2023(E)
© ISO 2023
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 11337:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Method A: Extraction method .1
4.1 Principle . 1
4.2 Reagents . 1
4.3 Apparatus and materials . 2
4.4 Preparation of test sample . 3
4.5 Procedure . 4
4.5.1 Test portion . 4
4.5.2 Extraction . 4
4.5.3 Preparation of internal-standard solution . 4
4.5.4 Preparation of sample solution . 4
4.5.5 Preparation of calibration solution . 4
4.5.6 Gas-chromatographic analysis of sample and calibration solutions . 4
4.5.7 Evaluation of gas chromatographic peaks . 5
4.6 Expression of results . . 5
4.7 Precision . . . 5
4.8 Test report . 6
5 Method B: Dissolution method . 6
5.1 Principle . 6
5.2 Reagents . 6
5.3 Apparatus . 7
5.4 Preparation of internal-standard solutions . 8
5.4.1 General . 8
5.4.2 Internal standard for unextracted polyamide 6 . 8
5.4.3 Internal standard for extracted polyamide 6 . 8
5.4.4 Internal standard for polyamide 12 . 8
5.4.5 Preparation of calibration solutions . 9
5.4.6 Calibration . . . 10
5.5 Procedure . 10
5.5.1 Preparation and injection of sample solution . 10
5.5.2 Evaluation of gas-chromatographic peaks. 10
5.5.3 Solvent recovery . 10
5.6 Expression of results . . 11
5.7 Precision . . . 11
5.8 Test report . 11
iii
ISO 11337:2023(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 Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9,
Thermoplastic materials, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 249, Plastics, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 11337:2010), which has been technically
revised.
The main changes are as follows:
— isopropanol has been added as suitable internal standard for method A;
— the use of packed and capillary columns has been indicated specifically;
— the specification of suitable detectors has been opened.
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
INTERNATIONAL STANDARD ISO 11337:2023(E)
Plastics — Polyamides — Determination of ε-caprolactam
and ω-laurolactam by gas chromatography
SAFETY STATEMENT — Persons using this document should be familiar with normal laboratory
practice, if applicable. This document does not purport to address all of the safety concerns, if
any, associated with its use. It is the responsibility of the user to establish appropriate safety
and health practices and determine the applicability of regulatory limitations prior to use.
1 Scope
This document specifies a method for determining ε-caprolactam and ω-laurolactam in polyamides by
gas chromatography. It is applicable particularly to the determination of ε-caprolactam in polyamide 6
and ω-laurolactam in polyamide 12.
Two variants of the basic method are specified.
— Method A is an extraction method with boiling methanol, and the extract is injected into a gas
chromatograph.
— Method B is a method using a solvent, and the solution is injected into a gas chromatograph.
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 amendment) applies.
ISO 472, Plastics — Vocabulary
ISO 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes
of openings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Method A: Extraction method
4.1 Principle
A test portion is extracted with boiling methanol and a small volume of the extract is injected into a
gas chromatograph equipped with a suitable detector to separate and detect the volatile components.
The extract contains 1-dodecanol as an internal standard.
4.2 Reagents
During the analysis, use only reagents of recognized analytical grade.
ISO 11337:2023(E)
4.2.1 Solvent, such as methanol.
4.2.2 Internal standard, such as 1-dodecanol or isopropanol.
4.2.3 ε-Caprolactam.
4.3 Apparatus and materials
Ordinary laboratory apparatus, plus the following.
4.3.1 Mill, for reducing the sample to the required grain size.
A mill in which the sample is ground at a low temperature is preferred. Large pieces may be reduced in
size with a pair of scissors before they are fed to the mill.
4.3.2 Two sieves, with aperture sizes of 710 µm and 500 µm, respectively, in accordance with the
requirements of ISO 565.
4.3.3 Extraction apparatus, that can accommodate an extraction crucible or porous ceramic thimble
containing the test portion.
The apparatus shall be of such a design that the crucible or thimble is heated by the rising methanol
vapour or the apparatus shall be constructed of an extraction flask with a Soxhlet-type reflux condenser.
Examples of suitable extraction apparatus designed along these lines are
EXAMPLE 1
— 250 ml extraction flask;
— extraction chamber to accommodate the extraction crucible so that it is enveloped on all sides by the rising
methanol vapour and the condensed methanol drips through it continuously;
— glass triangle to support the crucible;
— reflux condenser;
— sintered-glass filter crucible, pore size 40 µm to 50 µm, capacity 30 ml;
— porcelain filter-plate of slightly smaller diameter than the crucible, with holes of diameter 0,4 mm.
EXAMPLE 2
— 250 ml extraction flask;
— jacketed Soxhlet extractor;
— reflux condenser;
— sintered-glass filter crucible, pore size 40 µm to 50 µm, capacity 30 ml, or a porous ceramic thimble of similar
capacity (the dimensions shall be such that the crucible or thimble can be satisfactorily accommodated in the
Soxhlet apparatus);
— porcelain filter-plate of slightly smaller diameter than the crucible or thimble, as appropriate, with holes of
diameter 0,4 mm.
4.3.4 Heating device, suitable heating device for extraction apparatus.
4.3.5 Analytical balance, accurate to ±0,2 mg.
4.3.6 Liquid nitrogen or solid carbon dioxide, if necessary.
ISO 11337:2023(E)
4.3.7 Gas chromatograph, with suitable detector.
Both, packed and capillary columns may be used.
a) Column
The following columns are suitable:
1)
— a packed column, e.g. a glass column (3 mm Ø × 1,6 m), packed with acid-washed Chromosorb® W
of particle diameter 0,149 mm to 0,177 mm (80 mesh to 100 mesh) coated with 10 % (by mass)
poly(ethylene glycol) 20M;
TM1)
— a capillary column, e.g. a megabore Carbowax column (0,53 mm Ø × 15 m), of corresponding
separation efficiency.
The method of packing is not specified but shall be such as to obtain satisfactory separation efficiency.
Other column dimensions may be used as long as a sufficient separation efficiency is achieved.
A capillary column may also be used.
Suggested operating conditions for using a glass column and an FID detector are shown in Table 1.
a
Table 1 — Operating conditions for gas chromatograph with packed column and FID detector
Item Value
Column temperature 200 °C
Injector temperature 250 °C
Detector temperature 250 °C
Carrier gas Helium or nitrogen
Carrier gas flow rate 20 ml/min
a
These values apply to the packed column indicated in 4.3.7 a)
Other types of columns and/or detectors can require different operating temperatures and types and
flow rates of carrier and makeup gas.
b) Detector
Use a suitable detector with adequate selection of operating t
...