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ICS ČSN EN ISO OPRAVA Srpen 2009 ČESKÁ TECHNICKÁ NORMA Usně Chemické stanovení obsahu formaldehydu Část 1: Metoda vysokorychlostní kapalinové chromatografie Úřad pro technickou

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ICS ČSN EN ISO OPRAVA Srpen 2009 ČESKÁ TECHNICKÁ NORMA Usně Chemické stanovení obsahu formaldehydu Část 1: Metoda vysokorychlostní kapalinové chromatografie Úřad pro technickou normalizaci, metrologii a státní zkušebnictví, 2009 Podle zákona č. 22/1997 Sb. smějí být české technické normy rozmnožovány a rozšiřovány jen se souhlasem Úřadu pro technickou normalizaci, metrologii a státní zkušebnictví. EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO May 2008 ICS English Version Leather - Chemical determination of formaldehyde content - Part 1: Method using high performance liquid chromatography (ISO :2008) Cuir - Dosage chimique du formaldéhyde - Partie 1: Méthode par chromatographie en phase liquide à haute performance (ISO :2008) Leder - Chemische Prüfungen - Teil 1: Bestimmung des Formaldehydgehalts in Leder durch Hochleistungs- Flüssigkeitschromatographie (ISO :2008) This European Standard was approved by CEN on 26 April 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 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO :2008: E EN ISO :2008 (E) Contents Page Foreword...3 2 EN ISO :2008 (E) Foreword This document (EN ISO :2008) has been prepared by Technical Committee CEN/TC 289 Leather , the secretariat of which is held by UNI in collaboration with Technical Committee ISO/TC IULTCS International Union of Leather Technologists and Chemists Societies . 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 November 2008, and conflicting national standards shall be withdrawn at the latest by November Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. 3 INTERNATIONAL STANDARD ČSN EN ISO /Opr. 1 ISO IULTCS/IUC 19-1 First edition Leather Chemical determination of formaldehyde content Part 1: Method using high performance liquid chromatography Cuir Dosage chimique du formaldéhyde Partie 1: Méthode par chromatographie en phase liquide à haute performance Reference number ISO :2008(E) IULTCS/IUC 19-1:2008(E) ISO 2008 ISO :2008(E) IULTCS/IUC 19-1:2008(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. COPYRIGHT PROTECTED DOCUMENT ISO 2008 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 Fax Web Published in Switzerland ii ISO 2008 All rights reserved ISO :2008(E) IULTCS/IUC 19-1:2008(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 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 in Cancún, 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 sampling and the testing of leather. ISO recognizes IULTCS as an international standardizing body for the preparation of test methods for leather. This first edition of ISO , together with ISO , cancels and replaces ISO/TS 17226:2003, which has been technically revised. ISO consists of the following parts, under the general title Leather Chemical determination of formaldehyde content: Part 1: Method using high performance liquid chromatography Part 2: Method using colorimetric analysis ISO 2008 All rights reserved iii INTERNATIONAL STANDARD ISO :2008(E) IULTCS/IUC 19-1:2008(E) Leather Chemical determination of formaldehyde content Part 1: Method using high performance liquid chromatography 1 Scope This part of ISO specifies a method for the determination of free and released formaldehyde in leathers. This method is based on high performance liquid chromatography (HPLC). It is selective and not sensitive to coloured extracts. The formaldehyde content is taken to be the quantity of free-formaldehyde and formaldehyde extracted through hydrolysis contained in a water extract from the leather under standard conditions. 2 Conformance When compared with ISO , the two analytical methods should give similar trends but not necessarily the same absolute result. Therefore, in the case of dispute, this method (ISO ) shall be used in preference to ISO Normative references The following referenced documents are indispensable for the application 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 3696:1987, Water for analytical laboratory use Specification and test methods ISO 4044, Leather Chemical tests Preparation of chemical test samples ISO 4684, Leather Chemical tests Determination of volatile matter 4 Principle The process is selective. Formaldehyde is separated and quantified as a derivative from other aldehydes and ketones by liquid chromatography. Detected is the free-formaldehyde and formaldehyde which is hydrolysed during extraction to yield free-formaldehyde. The sample is eluted with detergent solution at 40 C. The eluate is mixed with 2,4-dinitrophenylhydrazine, whereby aldehydes and ketones react to give the respective hydrazones. These are separated by means of a reversed-phase HPLC method, detected at 360 nm and quantified. ISO 2008 All rights reserved 1 ISO :2008(E) IULTCS/IUC 19-1:2008(E) 5 Reagents Use only reagents of recognized analytical grade, unless otherwise stated. The water shall be grade 3 in accordance with ISO 3696:1987. All solutions are aqueous solutions. 5.1 Reagents for the formaldehyde stock solution Formaldehyde solution, approximately 37 % (mass fraction) Iodine solution, 0,05 mol/l, i.e. 12,68 g iodine per litre Sodium hydroxide solution, 2,0 mol/l Sulfuric acid solution, 2,0 mol/l Sodium thiosulfate solution, 0,1 mol/l Starch solution, 1 %, i.e. 1 g in 100 ml water. 5.2 Reagents for the HPLC method Sodium dodecylsulfonate (detergent) solution, 0,1 %, 1 g in ml water Dinitrophenylhydrazine (DNPH) solution, consisting of 0,3 g DNPH (2,4-dinitrophenylhydrazine) dissolved in 100 ml concentrated o-phosphoric acid (85 % mass fraction). (DNPH recrystallized from 25 % mass fraction, acetonitrile in water) Acetonitrile. 6 Apparatus Use usual laboratory equipment and, in particular, the following. 6.1 Volumetric flasks, of capacities 10 ml, 500 ml and ml. 6.2 Erlenmeyer flasks, of capacities 100 ml and 250 ml. 6.3 Strainer with glass fibre filter, GF8 (or glass filter strainer G 3, diameter 70 mm to 100 mm). 6.4 Water bath, thermostatically controlled to 40 C ± 0,5 C, fitted with a flask shaker or stirrer. 6.5 Thermometer, with 0,1 C graduations over the range 20 C to 50 C. 6.6 HPLC system with UV detection, 360 nm. 6.7 Membrane filter, polyamide, 0,45 µm. 6.8 Analytical balance, weighing to an accuracy of 0,1 mg. 2 ISO 2008 All rights reserved ISO :2008(E) IULTCS/IUC 19-1:2008(E) 7 Procedures 7.1 Procedure for the determination of formaldehyde in the stock solution Preparation of the formaldehyde stock solution Pipette 5 ml of the formaldehyde solution (5.1.1) into a ml volumetric flask (6.1) which contains approximately 100 ml water and then fill the flask with demineralized water up to the mark. This solution is the formaldehyde stock solution Determination Pipette 10 ml from this solution into a 250 ml Erlenmeyer flask (6.2) and mix with the 50 ml iodine solution (5.1.2). Add sodium hydroxide (5.1.3) until it turns yellow. Allow it to react for 15 min ± 1 min at 18 C to 26 C and then add 15 ml of sulfuric acid (5.1.4) while swirling. After adding 2 ml of starch solution (5.1.6), titrate the excess iodine with sodium thiosulfate (5.1.5) until the colour changes. Make three individual determinations. Titrate at least two blank solutions in the same manner. ρ FA = ( ) V V c M FA 2 where ρ FA V 0 V 1 M FA c 1 is the concentration of the formaldehyde stock solution, in milligrams per 10 ml (mg/10 ml); is the titre of the thiosulfate solution for the blank solution, in millilitres (ml); is the titre of the thiosulfate solution for the sample solution, in millilitres (ml); is the relative molecular mass of formaldehyde, 30,02 g/mol; is the concentration of the thiosulfate solution, in moles per litre (mol/l). 7.2 Procedure for the determination of formaldehyde in leather by the HPLC method Sampling and preparation of samples If possible, sample in accordance with ISO If sampling in accordance with ISO 2418 is not possible (e.g. leathers from finished products like shoes, garments), provide details about sampling together with the test report. Grind the leather in accordance with ISO If the result is to be presented on the basis of dry substance, then test a further sample of the same leather in accordance with ISO 4684 so that the moisture content can be calculated Extraction Weigh 2 g ± 0,1 g leather into a suitable vessel. Pipette 50 ml of the detergent solution (5.2.1) into a 100 ml Erlenmeyer flask (6.2) and warm it to 40 C. Transfer the pre-weighed leather quantitatively to the flask, then close it with a glass stopper (see next paragraph). Stir the content of the flask or shake it smoothly at 40 C ± 0,5 C in a water bath (6.4) for 60 min ± 2 min. Immediately filter the warm extract solution by vacuum through a glass fibre filter (6.3) into a flask. Cool the filtrate, in a closed flask, down to room temperature (18 C to 26 C). Do not modify the leather/solution ratio. Extraction and analysis should be performed within the same working day. ISO 2008 All rights reserved 3 ISO :2008(E) IULTCS/IUC 19-1:2008(E) Reaction with DNPH Pipette 4,0 ml of acetonitrile (5.2.3), a 5,0 ml aliquot of the filtered eluate (7.2.2) and 0,5 ml of DNPH solution (5.2.2) into a 10 ml volumetric flask (6.1). Fill the volumetric flask with demineralized water up to the mark and shake it briefly by hand to mix the components. Allow it to stand at least 60 min, but not more than a maximum of 180 min. After filtering through a membrane filter (6.7), analyse the sample using HPLC. If the concentration is out of the calibration range, take smaller aliquots HPLC conditions (recommendations) These conditions are only recommendations. The method used should be verified using the recovery rate determination (7.2.7) and the results observed should be in the range listed in Table A.1. Flow rate: 1,0 ml/min Mobile phase: acetonitrile/water, 60:40 Separation column: UV detection wavelength: C18 reversed phase column with precolumn (1 cm, RP18) 360 nm Injection volume: 20 µl NOTE A Merck 100, CH 18,2 (highly coated, 12 % C) column is an example of a suitable separation column which is commercially available. 1) Calibration of HPLC Pipette 0,5 ml of the formaldehyde stock solution obtained in 7.1.1, with an exactly known formaldehyde content, into a 500 ml volumetric flask (6.1), pre-filled with approximately 100 ml water. Mix together and fill to the mark with water, and mix again. This solution is the standard solution for calibration purposes, i.e. the standard solution is approximately 2 µg formaldehyde/ml. In each of six 10 ml volumetric flasks (6.1), add 4 ml acetonitrile (5.2.3), then add a concentration series of 0,5 ml; 1,0 ml; 2,0 ml; 3,0 ml; 4,0 ml; 5,0 ml, respectively, of the standard solution. Immediately upon addition of the formaldehyde solution (5.1.1), mix each flask and add 0,5 ml DNPH solution (5.2.2). Fill the flasks up to the mark with demineralized water and mix. After at least 60 min and not more than 180 min, analyse the samples using HPLC after filtration through a membrane filter (6.7). Effect the calibration through plotting a graph of the formaldehyde derivative peak area versus the concentration in micrograms per 10 ml Calculation of the formaldehyde content in leather samples w where F ρ S F = m w F is the concentration of formaldehyde in the sample in milligrams per kilogram (mg/kg) rounded to 0,01 mg/kg; ρ S is the concentration of formaldehyde obtained from the calibration graph in micrograms per 10 ml (µg/10 ml); 1) A Merck 100, CH 18,2 column is an example of a suitable product available commercially. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO of this product. 4 ISO 2008 All rights reserved ISO :2008(E) IULTCS/IUC 19-1:2008(E) F m is the dilution factor in millilitres (ml); is the mass of leather weighed in grams (g) Spiking Determination of recovery rate Pre-fill 4 ml acetonitrile (5.2.3) into a 10 ml volumetric flask (6.1) and add an aliquot of 2,5 ml of the filtrate, obtained as described in Then add an accurately determined volume of the formaldehyde standard solution to give an almost equal concentration to that found in the sample. Further treat this solution following the procedure described in and determine ρ S2 following the procedure described in Carry out the determination and report the value in the test report. RR = ( ρ ρ ) S2 0,5 S 100 ρ FA1 where ρ S2 ρ S ρ FA1 is the concentration of formaldehyde obtained from the calibration graph in micrograms per 10 ml (µg/10 ml); is the concentration of formaldehyde in the non-spiked sample in micrograms per 10 ml (µg/10 ml); is the spiked quantity of formaldehyde in micrograms per 10 ml (µg/10 ml); R R is the recovery rate in percent, rounded off to 0,1 %. 8 Expression of results Express the formaldehyde concentration to the nearest 0,1 mg/kg based on the mass of the leather sample tested. If the results are to be reported on the basis of dry substance, multiply the results above by the factor 100/(100 w), where w is the moisture content in percent (%) according to ISO If the results are presented on the basis of dry substance, clearly mention this in the test report. 9 Test report The test report shall include the following: a) reference to this document (i.e. ISO ); b) type, origin and designation of the analysed leather sample and the sampling method used; c) the analytical procedure used; d) the analytical results for the formaldehyde content; e) any deviations from the analytical procedure, particularly any additional steps performed; f) the date of the test; g) if the results are determined on the basis of the dry substance this shall be reported. ISO 2008 All rights reserved 5 ISO :2008(E) IULTCS/IUC 19-1:2008(E) Annex A (informative) Precision: reliability of the chromatographic HPLC method The following data have been obtained in a collaborative trial with 10 laboratories on leather samples with unknown levels of formaldehyde. Table A.1 Reliability data of the chromatographic HPLC method Leather sample Mean formaldehyde content Repeatability r Reproducibility R Recovery rate mg/kg mg/kg mg/kg % A 7,65 1,27 3,13 94 B 17,69 3,82 7,97 96 C 28,69 5,40 11,42 91 D 102,16 20,82 64, ISO 2008 All rights reserved ISO :2008(E) IULTCS/IUC 19-1:2008(E) ICS Price based on 6 pages ISO 2008 All rights reserved Změna proti předchozí normě Původní název normy Usně Chemické určení obsahu formaldehydu Část 1: Metody používající vysokorychlostní kapalinovou chromatografii se nahrazuje názvem Usně Chemické stanovení obsahu formaldehydu Část 1: Metoda vysokorychlostní kapalinové chromatografie. Upozorně ní : Změny a doplňky, jakož i zprávy o nově vydaných normách jsou uveřejňovány ve Věstníku Úřadu pro technickou normalizaci, metrologii a stát
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