1、BRITISH STANDARDBS EN ISO 5398-3:2007Leather Chemical determination of chromic oxide content Part 3: Quantification by atomic absorption spectrometryThe European Standard EN ISO 5398-3:2007 has the status of a British StandardICS 59.140.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g
2、44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 5398-3:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2007 BSI 2007ISBN 978
3、0 580 55576 3National forewordThis British Standard is the UK implementation of EN ISO 5398-3:2007.The UK participation in its preparation was entrusted to Technical Committee TCI/69, Footwear, leather and coated fabrics.A list of organizations represented on this committee can be obtained on reques
4、t to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEURO
5、PEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 5398-3August 2007ICS 59.140.30English VersionLeather - Chemical determination of chromic oxide content - Part3: Quantification by atomic absorption spectrometry (ISO 5398-3:2007)Cuir - Dosage chimique de loxyde de chrome - Partie 3:Quantification par
6、 spectromtrie dabsorption atomique(ISO 5398-3:2007)Leder - Chemische Bestimmung des Chromoxidgehalts -Teil 3: Bestimmung durch Atomabsorptionsspektrometrie(ISO 5398-3:2007)This European Standard was approved by CEN on 28 July 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulat
7、ions which stipulate the conditions for giving this EuropeanStandard 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 Europ
8、ean Standard exists in three official versions (English, French, 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 nation
9、al 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 Unit
10、ed Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 5398-3:2007:
11、 EForeword This document (EN ISO 5398-3:2007) has been prepared by Technical Committee CEN/TC 289 “Leather“, the secretariat of which is held by UNI, in collaboration with the International Union of Leather Technologists and Chemists Societies (IULTCS). This European Standard shall be given the stat
12、us of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2008, and conflicting national standards shall be withdrawn at the latest by February 2008. According to the CEN/CENELEC Internal Regulations, the national standards organizations of th
13、e 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, Slovaki
14、a, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN ISO 5398-3:2007IULTC/IUC 8:3:2007Reference numberISO 5398-3:2007(E)IULTCS/IUC 8:3:2007(E)INTERNATIONAL STANDARD ISO5398-3IULTCS/IUC8:3First edition2007-08-01Leather Chemical determination of chromic oxide content Part 3: Quantificati
15、on by atomic absorption spectrometry Cuir Dosage chimique de loxyde de chrome Partie 3: Quantification par spectromtrie dabsorption atomique EN ISO 5398-3:2007IULTC/IUC 8:3:2007ii iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Normative references 1 3 Terms and definitions .1 4 Principle1 5
16、 Sampling and sample preparation.2 6 Reagents.2 6.1 Wet oxidation method .2 6.2 Atomic absorption spectrometry .2 7 Apparatus .2 8 Methods 3 8.1 Preparation of analytical solution3 8.2 Measurement of the aqueous solution3 9 Calculation and expression of results.4 10 Test report 5 Annex A (informativ
17、e) Determination of water and other volatile matter6 EN ISO 5398-3:2007IULTC/IUC 8:3:2007iv 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
18、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
19、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 Internationa
20、l 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 eleme
21、nts of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. This part of ISO 5398 was prepared by the Chemical Tests Commission of the International Union of Leather Technologists and Chemists Societies (IUC Commission, I
22、ULTCS) in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, the secretariat of which is held by UNI, in accordance with the agreement on technical co-operation between ISO and CEN (Vienna Agreement). It is based on IUC 8 originally published
23、 in J. Soc. Leather Trades Chemists 49, p. 17, (1965) and declared an official method of the IULTCS in 1965. 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, w
24、hich are responsible for establishing international methods for the sampling and testing of leather. ISO recognizes IULTCS as an international standardizing body for the preparation of test methods for leather. ISO 5398 consists of the following parts, under the general title Leather Chemical determ
25、ination of chromic oxide content: Part 1: Quantification by titration Part 2: Quantification by colorimetric determination Part 3: Quantification by atomic absorption spectrometry Part 4: Quantification by inductively coupled plasma optical emission spectrometer (ICP-OES) EN ISO 5398-3:2007IULTC/IUC
26、 8:3:2007vIntroduction ISO 5398 has been split into four parts, each describing methods suitable for the determination of the chromic oxide content in leather. The different techniques have been described to reflect the variations in industrial practice compared with the more sensitive analytical eq
27、uipment available for test laboratories. Variations also exist in the range of chromic oxide that the methods are deemed suitable to quantify. ISO 5398-3 describes a technique that is suitable for determining chromium more precisely than those described in ISO 5398-1 and ISO 5398-2. It requires the
28、use of sophisticated analytical equipment, such as atomic absorption spectroscopy. EN ISO 5398-3:2007IULTC/IUC 8:3:2007blank1Leather Chemical determination of chromic oxide content Part 3: Quantification by atomic absorption spectrometry 1 Scope This part of ISO 5398 describes a method for the deter
29、mination of chromium in aqueous solution obtained from leather. This is an analysis for total chromium in leather; it is not compound specific or specific to its oxidation state. This method describes the determination of chromium by atomic absorption spectrometry and is applicable to leathers which
30、 are expected to have chromic oxide contents in excess of 5 mg/kg. Two techniques for the preparation of the solution to be analysed are included. In the case of dispute, the wet oxidation technique is to be used. 2 Normative references The following referenced documents are indispensable for the ap
31、plication 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 fo
32、r 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 EN 14602, Footwear Test methods for the assessment of ecological criteria 3 Terms and definitions For the
33、 purposes of this document, the following terms and definitions apply. 3.1 chromic oxide content amount of chromium in leather, determined by this method and reported as chromic oxide NOTE The chromic oxide content is expressed in milligrams per kilogram (mg/kg), based on dry matter. 4 Principle The
34、 chromium present in the leather is solubilized in the hexavalent state followed by analysis of the solution by atomic absorption spectrometry. EN ISO 5398-3:2007IULTC/IUC 8:3:20072 5 Sampling and sample preparation If possible, sample in accordance with ISO 2418 and grind leather in accordance with
35、 ISO 4044. If sampling in accordance with ISO 2418 is not possible (as in the case of leathers from finished products like shoes, garments), details about sampling shall be given together with the test report. Weigh 2 g of the ground leather to the nearest 0,001 g. From every leather, a minimum of t
36、wo determinations shall be made. 6 Reagents Unless otherwise stated, only analytical grade chemicals are to be used. The water shall be grade 3 in accordance with ISO 3696:1987. All solutions are aqueous solutions. 6.1 Wet oxidation method 6.1.1 Nitric acid, 70 %. 6.1.2 Sulfuric acid, concentrated (
37、98 %), and perchloric acid (60 % to 70 %), mixed together in the ratio of 1:3 by volume. 6.2 Atomic absorption spectrometry 6.2.1 Potassium dichromate (K2Cr2O7), dried for 16 h 2 h at 102 C 2 C. 6.2.2 Potassium chloride (KCl). 6.2.3 Standard dichromate solution: dissolve 2,829 g of potassium dichrom
38、ate (6.2.1) in water in a volumetric flask and make up to 1 000 ml with water. 1 ml of this solution contains 1 mg of chromium. 6.2.4 Potassium chloride solution: dissolve 2 g of potassium chloride (6.2.2) in 1 l of distilled water. Add 1 ml of nitric acid (6.1.1) to each litre prepared. 7 Apparatus
39、 Usual laboratory apparatus is required and, in particular, the following. 7.1 Conical flask, 500 ml, with ground glass stopper. 7.2 Atomic absorption spectrophotometer, with suitable hollow cathode lamp and nitrous oxide burner head or high solids nitrous oxide burner head. 7.3 Filtration device, u
40、sing glass fibre (GFC) or membrane type filters. 7.4 Antibumping granules (or similar) (wet oxidation method). EN ISO 5398-3:2007IULTC/IUC 8:3:200738 Methods 8.1 Preparation of analytical solution 8.1.1 Wet oxidation method WARNING It is imperative that nitric acid is added first because of the poss
41、ible explosive reaction of perchloric acid with leather. Accurately weigh a mass of leather (see Clause 5) into the conical flask (7.1). Add 10 ml of nitric acid (6.1.1) and allow to stand for 2 min. Add 15 ml of mixed sulfuric/perchloric acids (6.1.2) and a few antibumping granules (7.4). Place a f
42、unnel or splash bulb in the neck of the flask and heat to boiling on a wire gauze over a moderate flame. As soon as the reaction mixture begins to turn orange, lower the flame. After a complete change of colour, heat gently for at least 2 min. Allow to cool in air for 5 min and dilute to approximate
43、ly 200 ml. Boil for 10 min to eliminate any chlorine. The use of a sulfuric/perchloric acid mixture is preferred to the use of the individual acids as it prevents the accidental use of perchloric acid alone. In the case of incomplete oxidation (i.e. the solution does not change to an orange colour),
44、 it is permissible to add further mixed sulfuric/perchloric acid to the sample. 8.1.2 Microwave digestion The sample for analysis can also be prepared through application of microwave-assisted digestion (MAD). If this is to be used, then the procedure described in EN 14602 shall be followed. 8.2 Mea
45、surement of the aqueous solution 8.2.1 General Prepare the atomic absorption spectrophotometer (7.2) by following the manufacturers instructions for adjusting all instrument parameters. Where it is noted that the setting is as recommended by the manufacturer, then the settings used should be those d
46、escribed by the manufacturer for chromium. Lamp current as recommended by manufacturer Slit width/band pass 0,5 nm Wavelength 357,9 nm Burner head single slot nitrous oxide or high solids nitrous oxide to give red cone 10 mm to 20 mm high Fuel flow as recommended by manufacturer Oxidant flow as reco
47、mmended by manufacturer Photomultiplier voltage as required to give optimum signal/noise ratio Before carrying out the spectrometric measurements, set up the spectrophotometer according to the manufacturers instructions by aspirating a 4,0 g/ml calibration solution. Optimize the aspiration and flame
48、 conditions (aspiration rate, nature of the flame, positions of the optical beam in the flame). Aspirate distilled water and adjust controls to give a steady zero (base-line) reading. EN ISO 5398-3:2007IULTC/IUC 8:3:20074 8.2.2 Preparation of calibration graph Prepare standard solutions by pipetting
49、 10 ml of the standard dichromate solution (6.2.3) into a 100 ml volumetric flask and making up to volume with distilled water. Pipette 2,0 ml, 4,0 ml, 6,0 ml and 8,0 ml aliquots of this solution into 100 ml volumetric flasks and make up to volume with potassium chloride solution (6.2.4). These solutions contain 2,0 g/ml, 4,0 g/ml, 6,0 g/ml and 8,0 g/ml of chromium respectively. Aspirate the standard solutions and prepare a standard calibration curve. This calibration may be retained in the spectrophotometers memory if p
