1、BS EN ISO17226-1:2008ICS 59.140.30NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDLeather Chemicaldetermination offormaldehyde contentPart 1: Method using high performanceliquid chromatography (ISO17226-1:2008)This British Standardwas published under theauthorit
2、y of the StandardsPolicy and StrategyCommittee on 30 June2009. BSI 2009ISBN 978 0 580 57525 9Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 17226-1:2008National forewordThis British Standard is the UK implementation of EN ISO 17226-1:2008. Together with BS EN ISO 17226-2:2008 i
3、t supersedes DD CEN ISO/TS 17226:2003, which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee TCI/69, Footwear, leather and coated fabrics.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does no
4、t purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 17226-1May 2008ICS 59.140.30 Supersedes CEN ISO/TS 1
5、7226:2003 English VersionLeather - Chemical determination of formaldehyde content - Part1: Method using high performance liquid chromatography (ISO17226-1:2008)Cuir - Dosage chimique du formaldhyde - Partie 1:Mthode par chromatographie en phase liquide hauteperformance (ISO 17226-1:2008)Leder - Chem
6、ische Bestimmung des Formaldehydgehalts -Teil 1: Hochleistungs-Flssigkeitschromatographie (ISO17226-1:2008)This European Standard was approved by CEN on 26 April 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStan
7、dard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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,
8、 German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech
9、 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 STANDARDIZATIONCOMIT EUROPEN D
10、E NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 17226-1:2008: EEN ISO 17226-1:2008 (E) 3 Foreword This document (EN ISO 1722
11、6-1:2008) 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 nation
12、al 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 2008. This document, together with EN ISO 17226-2:2008, supersedes CEN ISO/TS 17226:2003. Attention is drawn to t
13、he 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 coun
14、tries 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, Spa
15、in, Sweden, Switzerland and the United Kingdom. BS EN ISO 17226-1:2008ISO 17226-1:2008(E) IULTCS/IUC 19-1:2008(E) ISO 2008 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of
16、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,
17、 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 t
18、ask 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. Attent
19、ion 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 17226-1 was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 289
20、, 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 t
21、he Colorimetric Section of the method IUC 19 which was declared an official method at the IULTCS Delegates meeting on 31st May 2003 in Cancn, Mexico. IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to further the advancement of leather science and te
22、chnology. 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 17226-1, together with
23、 ISO 17226-2, cancels and replaces ISO/TS 17226:2003, which has been technically revised. ISO 17226 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 colori
24、metric analysis BS EN ISO 17226-1:2008BS EN ISO 17226-1:2008INTERNATIONAL STANDARD ISO 17226-1:2008(E)IULTCS/IUC 19-1:2008(E) ISO 2008 All rights reserved 1Leather Chemical determination of formaldehyde content Part 1: Method using high performance liquid chromatography 1 Scope This part of ISO 1722
25、6 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 forma
26、ldehyde extracted through hydrolysis contained in a water extract from the leather under standard conditions. 2 Conformance When compared with ISO 17226-2, the two analytical methods should give similar trends but not necessarily the same absolute result. Therefore, in the case of dispute, this meth
27、od (ISO 17226-1) shall be used in preference to ISO 17226-2. 3 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 (
28、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 Chemic
29、al 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-f
30、ormaldehyde. 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. BS EN ISO 17
31、226-1:2008ISO 17226-1:2008(E) IULTCS/IUC 19-1:2008(E) 2 ISO 2008 All rights reserved5 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 formaldehyd
32、e stock solution 5.1.1 Formaldehyde solution, approximately 37 % (mass fraction). 5.1.2 Iodine solution, 0,05 mol/l, i.e. 12,68 g iodine per litre. 5.1.3 Sodium hydroxide solution, 2,0 mol/l. 5.1.4 Sulfuric acid solution, 2,0 mol/l. 5.1.5 Sodium thiosulfate solution, 0,1 mol/l. 5.1.6 Starch solution
33、, 1 %, i.e. 1 g in 100 ml water. 5.2 Reagents for the HPLC method 5.2.1 Sodium dodecylsulfonate (detergent) solution, 0,1 %, 1 g in 1 000 ml water. 5.2.2 Dinitrophenylhydrazine (DNPH) solution, consisting of 0,3 g DNPH (2,4-dinitrophenylhydrazine) dissolved in 100 ml concentrated o-phosphoric acid (
34、85 % mass fraction). (DNPH recrystallized from 25 % mass fraction, acetonitrile in water) 5.2.3 Acetonitrile. 6 Apparatus Use usual laboratory equipment and, in particular, the following. 6.1 Volumetric flasks, of capacities 10 ml, 500 ml and 1 000 ml. 6.2 Erlenmeyer flasks, of capacities 100 ml and
35、 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
36、detection, 360 nm. 6.7 Membrane filter, polyamide, 0,45 m. 6.8 Analytical balance, weighing to an accuracy of 0,1 mg. BS EN ISO 17226-1:2008ISO 17226-1:2008(E) IULTCS/IUC 19-1:2008(E) ISO 2008 All rights reserved 37 Procedures 7.1 Procedure for the determination of formaldehyde in the stock solution
37、 7.1.1 Preparation of the formaldehyde stock solution Pipette 5 ml of the formaldehyde solution (5.1.1) into a 1 000 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.
38、7.1.2 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.
39、 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. ()01 1 FAFA2VV cM= where FAis the concentration of the formaldehyde stock
40、solution, in milligrams per 10 ml (mg/10 ml); V0is the titre of the thiosulfate solution for the blank solution, in millilitres (ml); V1is the titre of the thiosulfate solution for the sample solution, in millilitres (ml); MFAis the relative molecular mass of formaldehyde, 30,02 g/mol; c1is the conc
41、entration of the thiosulfate solution, in moles per litre (mol/l). 7.2 Procedure for the determination of formaldehyde in leather by the HPLC method 7.2.1 Sampling and preparation of samples If possible, sample in accordance with ISO 2418. If sampling in accordance with ISO 2418 is not possible (e.g
42、. leathers from finished products like shoes, garments), provide details about sampling together with the test report. Grind the leather in accordance with ISO 4044. 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
43、4684 so that the moisture content can be calculated. 7.2.2 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
44、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 ro
45、om temperature (18 C to 26 C). Do not modify the leather/solution ratio. Extraction and analysis should be performed within the same working day. BS EN ISO 17226-1:2008ISO 17226-1:2008(E) IULTCS/IUC 19-1:2008(E) 4 ISO 2008 All rights reserved7.2.3 Reaction with DNPH Pipette 4,0 ml of acetonitrile (5
46、.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
47、 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. 7.2.4 HPLC conditions (recommendations) These conditions are only recommendations. The method used should be verified usin
48、g 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: C18 reversed phase column with precolumn (1 cm, RP18) UV detection wavelength: 360 nm Injection volume: 20 l
49、 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)7.2.5 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 so
