prEN 18079

SLOVENSKI STANDARD
01-junij-2024
Lesne plošče - Določevanje melamina z ekstrakcijo in s tekočinsko kromatografijo
visoke ločljivosti (HPLC) z ultravijolično detekcijo
Wood-based panels - Determination of melamine applying extraction and high-
performance chromatography (HPLC) with ultraviolet detection
Holzwerkstoffe - Bestimmung von Melamin durch Extraktion und
Hochleistungschromatographie (HPLC) mit Ultraviolett-Detektion
Panneaux à base de bois - Détermination de la mélamine par extraction et
chromatographie liquide à haute performance (HPLC) avec détection ultraviolet
Ta slovenski standard je istoveten z: prEN 18079
ICS:
79.060.01 Lesne plošče na splošno Wood-based panels in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2024
ICS 79.060.01
English Version
Wood-based panels - Determination of melamine applying
extraction and high-performance chromatography (HPLC)
with ultraviolet detection
Panneaux à base de bois - Détermination de la Holzwerkstoffe - Bestimmung von Melamin durch
mélamine par extraction et chromatographie haute Extraktion und Hochleistungschromatographie (HPLC)
performance (HPLC) avec détection ultraviolette mit Ultraviolett-Detektion
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 112.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.
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.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 18079:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Reagents . 5
6 Apparatus . 5
7 Sampling . 6
7.1 General. 6
7.2 Sample preparation . 6
7.3 Extraction . 6
7.3.1 General procedure solid sample material . 6
7.3.2 General procedure liquid sample material . 7
7.3.3 Extract dilution for low melamine content . 7
7.3.4 Extract dilution for high melamine content . 7
8 Procedure . 7
8.1 HPLC analysis . 7
8.1.1 General. 7
8.1.2 Eluent preparation . 7
8.1.3 HPLC parameters . 7
8.1.4 Calibration . 7
8.1.5 Measurement and calculation . 8
8.1.6 Detection limits . 9
8.1.7 Quality assurance . 9
8.1.8 Maintenance . 9
9 Test report . 9
Annex A (informative) Example of HPLC parameters . 11
Annex B (informative) Example for an estimation of detection limits . 13
Bibliography . 14

European foreword
This document (prEN 18079:2024) has been prepared by Technical Committee CEN/TC 112 “Wood-
based panels”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
Introduction
Melamine is part of adhesives (melamine-urea-formaldehyde resins, MUF) and impregnation resins
(melamine-formaldehyde-resins, MF) and is therefore present in wood-based products as well as
products with a decorative wear layer. Fully cured products contain mainly chemically bound melamine,
which makes the presence of free melamine unlikely.
Melamine (2,4,6-Triamino-l,3,5-triazine) is a heterocyclic, aromatic substance (CAS 108-78-1), see
Figure 1. It is a white solid at room temperature with a melting point of 280 °C. It decomposes above this
temperature. Melamine is poorly soluble in cold water. In hot water, melamine has a significantly higher
solubility. Dimethyl sulfoxide (DMSO) is an inert solvent and capable for melamine quantification.

Figure 1 — Melamine structure (CAS: 108-78-1), molar mass 126,12 g/mol
1 Scope
This document specifies the determination of free melamine in coated and uncoated wood-based-panels.
NOTE 1 It is also applicable to other wood-based products, to other solid products e.g. impregnates or decorative
paper and to liquid products (e.g. adhesives).
The determination of melamine is performed by extraction in dimethyl sulfoxide (DMSO) and subsequent
high-performance chromatography (HPLC) analysis and ultraviolet (UV) detection.
NOTE 2 For determination of melamine in foodstuff EN 16858 is applicable. For determination of melamine in
animal feeding stuffs EN 17212 is applicable. For determination of melamine in textiles EN ISO 1833-26 is
applicable.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 322, Wood-based panels — Determination of moisture content
EN 326-1, Wood-based panels — Sampling, cutting and inspection — Part 1: Sampling and cutting of test
pieces and expression of test results
3 Terms and definitions
No terms and definitions are listed in this document.
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 Principle
A sample of a wood-based panel product is milled and extracted with dimethyl sulfoxide (DMSO). After
adding acetonitrile, the content of free melamine in the solution is determined by high-performance
chromatography (HPLC) analysis and UV detection.
5 Reagents
5.1 Dimethyl sulfoxide (DMSO) of analytical grade.
5.2 Water (deionized).
5.3 Acetonitrile (AcN) of analytical grade.
5.4 Ammonium acetate of analytical grade.
5.5 Melamine of analytical grade.
6 Apparatus
6.1 Cryomill (recommended).
6.2 Drying oven for determination of solid content.
6.3 HPLC device offering column oven and diode array detector (DAD).
6.4 Laboratory shaker.
6.5 Screw cap bottles, 20 ml.
6.6 HPLC vials, 2 ml.
6.7 Disposable filter (PTFE, 0,2 µm), disposable syringe.
7 Sampling
7.1 General
A representative sample of the wood-based panel product to be tested is collected. From this sample a
set of 5 pieces shall be cut and used for further determination. The sample pieces shall be cut according
to EN 326-1. The sample and the sample pieces shall be stored in dust-free and moisture-impermeable
containers or bags (aluminium or PE).
NOTE Other solid materials (wood-based products, decoration paper, impregnates, dust, laminate) and liquids
(resins) can also be sampled and investigated.
The sample preparation is adapted to the content of free melamine expected in the sample material. High
contents of free melamine are expected in resins and not fully cured samples only. The extracts will be
diluted to preserve the HPLC column. DMSO dissolves not only melamine but also resin components
present in not fully cured samples. These components shall be separated before HPLC analysis. Therefore,
acetonitrile is added leading to precipitation of these resin components.
Free melamine soluble in DMSO remains dissolved and is completely available to subsequent analysis.
Due to this dilution step the sample and the eluent will be narrowed regarding their solvents also.
7.2 Sample preparation
The solid sample material is milled to particle size preferably below 1 mm. To avoid excessive heat,
cryomilling is recommended. A representative sample amount requires 10 g of the test material. The
sample material shall be stored in dust-protected bags at room temperature. A determination of solids
content is performed according to EN 322.
NOTE Liquid samples (resins) are stored as specified in the safety and technical data sheets at room
temperature or in a refrigerator at (6 ± 2) °C. Just before the sampling liquid material is homogenized by shaking. A
determination of solids content is performed according to EN 827.
7.3 Extraction
7.3.1 General procedure solid sample material
1 g of homogenized sample material is weighed in a 20 ml screw cap bottle. 10 ml DMSO is added, and
the bottle is closed thoroughly.
If less than 1 g sample material is available, the entire material is used for determination and the DMSO
volume shall be adapted.
The sample is extracted by constant shaking for 2 h at room temperature.
7.3.2 General procedure liquid sample material
100 mg homogenized sample material is weighed in a 10 ml volumetric flask, DMSO is filled to the mark,
and the flask is closed thoroughly. The sample is extracted by constant shaking for 2 h at room
temperature.
7.3.3 Extract dilution for low melamine content
1 ml of sample extract is transferred into a 20 ml screw cap bottle and added by 9 ml acetonitrile.
Depending on the curing state, resin components precipitate while melamine is still so
...