oSIST prEN ISO 25202:2025

Leather - Chemical analysis - Determination of glutaraldehyde content (ISO/DIS 25202:2024)

This international standard specifies a method for the determination of the content of Leather.
This method is based on high performance liquid chromatography (HPLC). It is selective and not sensitive to coloured extracts.

Leder - Chemische Analyse - Bestimmung des Glutaraldehydgehalts (ISO/DIS 25202:2024)

Cuir - Analyse chimique - Détermination de la teneur en glutaraldéhyde (ISO/DIS 25202:2024)

Usnje - Kemijska analiza - Določevanje vsebnosti glutaraldehida (ISO/DIS 25202:2024)

General Information

• Status: Not Published
• Public Enquiry End Date: 27-Feb-2025
• ICS: 59.140.30 - Leather and furs
• ICS: 71.040.40 - Chemical analysis
• Technical Committee: IUSN - Leather
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 19-Dec-2024
• Due Date: 08-May-2025
• Completion Date: 03-Mar-2025
• Ref Project: prEN ISO 25202 - Leather - Chemical analysis - Determination of glutaraldehyde content (ISO/DIS 25202:2024)

Overview

prEN ISO 25202 (ISO/DIS 25202:2024) is a draft international standard, prepared under CEN in collaboration with IULTCS, that specifies a chemical analysis method for the determination of glutaraldehyde content in leather. The method targets both free and released glutaraldehyde and uses liquid chromatography (HPLC/LC) after derivatization. It is selective and designed to be robust against coloured extracts.

Key topics and technical requirements

• Scope: Quantification of free and released glutaraldehyde in leather samples using LC.
• Principle: Leather is extracted with a detergent solution at 40 °C; aldehydes/ketones are derivatized with 2,4‑dinitrophenylhydrazine (DNPH) to form hydrazones, separated by reversed‑phase LC and detected by UV.
• Detection: UV detection at (355 ± 5) nm for DNPH-hydrazone derivatives.
• Reagents: water (ISO 3696 grade), glutaraldehyde standard (derivatized or non‑derivatized), DNPH solution, acetonitrile, and a detergent (SDS/SDSO).
• Apparatus: thermostatted water bath (40 ± 2 °C) with shaker, LC system with UV detector, membrane filters (0.45 µm), analytical balance, volumetric glassware.
• Sample prep & extraction: follow ISO 2418 and ISO 4044 for sampling and specimen preparation; extract ~2 g leather in 50 ml detergent solution, filter and derivatize aliquots with DNPH.
• Calibration and range: calibration solutions prepared to cover 0.1–2.0 µg/ml (stated to correspond to approximately 5–100 mg/kg glutaraldehyde in leather under the specified conditions).
• Result expression: report glutaraldehyde concentration as mg/kg leather to 0.1 mg/kg.
• Quality: the standard includes instructions for calibration, sample dilution for high concentrations, and references an informative annex with LC conditions.

Practical applications and users

• Who uses it: leather chemists, analytical laboratories, tanneries, quality control teams, product safety/test houses, and regulatory bodies inspecting chemical content in leather goods.
• Why use it:
  • Monitor and control glutaraldehyde levels in tanning and finishing processes.
  • Verify compliance with internal or regulatory limits for residual aldehydes (health and safety).
  • Support product safety documentation, material declarations, and R&D optimisation of tanning processes.
• Benefits: selective, HPLC‑based measurement that is not affected by coloured extracts and provides traceable, quantitative results suitable for laboratory quality control and regulatory reporting.

Related standards

• ISO 2418 - sampling and specimen position/preparation
• ISO 4044 - preparation of chemical test samples
• ISO 3696 - laboratory water quality
• Methodology aligned with IULTCS/IUC procedures (notably similar to the Colourimetric Section of IUC 19)

Keywords: prEN ISO 25202, ISO/DIS 25202:2024, glutaraldehyde, leather chemical analysis, HPLC, DNPH, liquid chromatography, leather testing, CEN, IULTCS.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2025
Usnje - Kemijska analiza - Določevanje vsebnosti glutaraldehida (ISO/DIS
25202:2024)
Leather - Chemical analysis - Determination of glutaraldehyde content (ISO/DIS
25202:2024)
Leder - Chemische Analyse - Bestimmung des Glutaraldehydgehalts (ISO/DIS
25202:2024)
Cuir - Analyse chimique - Détermination de la teneur en glutaraldéhyde (ISO/DIS
25202:2024)
Ta slovenski standard je istoveten z: prEN ISO 25202
ICS:
59.140.30 Usnje in krzno Leather and furs
71.040.40 Kemijska analiza Chemical analysis
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 25202
IULTCS
IUC 40
IULTCS
Leather — Chemical analysis —
Secretariat: ISO
Determination of glutaraldehyde
content
Voting begins on:
2024-12-11
ICS: 59.140.30
Voting terminates on:
2025-03-05
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference numbers
ISO/DIS 25202:2024(en)
IULTCS/IUC 40:2024(en)
DRAFT
ISO/DIS 25202:2024(en)
International
Standard
ISO/DIS 25202
IULTCS
IUC 40
IULTCS
Leather — Chemical analysis —
Secretariat: ISO
Determination of glutaraldehyde
content
Voting begins on:
ICS: 59.140.30
Voting terminates on:
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2024
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Reference numbers
Published in Switzerland ISO/DIS 25202:2024(en)
IULTCS/IUC 40:2024(en)
ii
ISO/DIS 25202:2024(en)
IULTCS/IUC 40:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 1
6 Apparatus . 2
7 Preparation of test specimens . 2
8 Procedure . 3
8.1 Sample processing .3
8.1.1 Extraction .3
8.1.2 Reaction with DNPH .3
8.2 Determination by LC .3
9 Expression of results . 4
9.1 General .4
9.2 Calculation of the glutaraldehyde content .4
9.3 Precision of the test method .4
10 Test report . 4
Annex A (informative) LC conditions . 5
Bibliography . 6

iii
ISO/DIS 25202:2024(en)
IULTCS/IUC 40:2024(en)
Foreword
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This document was prepared by the European Committee for Standardization (CEN) Technical Committee
CEN/TC 289, Leather, in collaboration with the Chemical Test Commission of the International Union of
Leather Technologists and Chemists Societies (IUC Commission, IULTCS), in accordance with the Agreement
on technical cooperation between ISO and CEN (Vienna Agreement). This method is technically similar to
the Colorimetric Section of the method IUC 19 which was declared an official method at the IULTCS Delegates
meeting on 31st May 2003 i
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