BS-EN-12441-5-2003.pdf
BRITISH STANDARD BS EN 12441-5:2003 Zinc and zinc alloys Chemical analysis Part 5: Determination of iron in primary zinc Spectrophotometric method The European Standard EN 12441-5:2003 has the status of a British Standard ICS 77.040.30; 77.120.60 ? Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 12441-5:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 3 April 2003 © BSI 3 April 2003 ISBN 0 580 41492 2 National foreword This British Standard is the official English language version of EN 12441-5:2003. It supersedes BS 3630-5:1963 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee NFE/8, Zinc and zinc alloys, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. 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 does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 12441-5 March 2003 ICS 77.040.30; 77.120.60 English version Zinc and zinc alloys - Chemical analysis - Part 5: Determination of iron in primary zinc - Spectrophotometric method Zinc et alliages de zinc - Analyse chimique - Partie 5: Dosage du fer dans le zinc primaire - Méthode spectrophotométrique Zink und Zinklegierungen - Chemische Analyse - Teil 5: Bestimmung von Eisen in Primärzink - Spektrophotometrisches Verfahren This European Standard was approved by CEN on 21 November 2002. 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 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, 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 © 2003 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12441-5:2003 E Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12441-5:2003 (E) 2 Contents page Foreword3 1Scope 4 2Normative references 4 3Terms and definitions4 4Principle4 5Reagents.4 6Apparatus .5 7Sampling.5 8Procedure .5 9Calculation and expression of results.7 10Test report 7 Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12441-5:2003 (E) 3 Foreword This document (EN 12441-5:2003) has been prepared by Technical Committee CEN /TC 209 “Zinc and zinc alloys“, the secretariat of which is held by AFNOR. 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 September 2003, and conflicting national standards shall be withdrawn at the latest by September 2003. Within its programme of work, Technical Committee CEN/TC 209 entrusted CEN/TC 209/WG 6, “Methods of analysis and testing” with the preparation of the following document: EN 12441-5, Zinc and zinc alloys - Chemical analysis Part 5: Determination of iron in primary zinc Spectrophotometric method. This standard is part of series of eleven standards. The other standards are: EN 12441-1, Zinc and zinc alloys Chemical analysis Part 1: Determination of aluminium in zinc alloys Titrimetric method; EN 12441-2, Zinc and zinc alloys Chemical analysis Part 2: Determination of magnesium in zinc alloys Flame atomic absorption spectrometric method; EN 12441-3, Zinc and zinc alloys Chemical analysis Part 3: Determination of lead, cadmium and copper Flame atomic absorption spectrometric method; EN 12441-4, Zinc and zinc alloys Chemical analysis Part 4: Determination of iron in zinc alloys Spectrophotometric method EN 12441-6, Zinc and zinc alloys Chemical analysis Part 6: Determination of aluminium and iron Flame atomic absorption spectrometric method; prEN 12441-7, Zinc and zinc alloys Chemical analysis Part 7: Determination of tin Flame atomic absorption spectrometric method after extraction; prEN 12441-8, Zinc and zinc alloys Chemical analysis Part 8: Determination of tin in secondary zinc Flame atomic absorption spectrometric method; prEN 12441-9, Zinc and zinc alloys Chemical analysis Part 9: Determination of nickel in zinc alloys Flame atomic absorption spectrometric method; prEN 12441-10, Zinc and zinc alloys Chemical analysis Part 10: Determination of chromium and titanium in zinc alloys Spectrophotometric method; prEN 12441-11, Zinc and zinc alloys Chemical analysis Part 11: Determination of silicon in zinc alloys Spectrophotometric method; According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12441-5:2003 (E) 4 1 Scope This European Standard specifies a spectrophotometric method for the determination of iron in primary zinc. It is applicable to the products specified in EN 1179. It is suitable for the determination of iron contents (mass fractions) between 0,001 % and 0,1 %. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 1179, Zinc and zinc alloys - Primary zinc. EN 12060:1997, Zinc and zinc alloys - Method of sampling Specifications. 3 Terms and definitions For the purposes of this European Standard, the terms and definitions given in EN 12060:1997 apply. 4 Principle Formation of a sulfosalicylic acid ferric complex in an ammoniacal medium. Spectrophotometric measurement of the yellow colour of the thus formed complex. 5 Reagents 5.1 General During the test, use only reagents of known analytical grade and distilled or demineralised water. 5.2Ammonia solution, = 0,91 g/ml. 5.3Hydrochloric acid, = 1,19 g/ml. 5.4Hydrogen peroxide, 30 % (mass fraction). 5.5Sulfosalicylic acid, 400 g/l solution. 5.6Nickel chloride solution Dissolve 2 g of nickel chloride hexahydrate (NiCl2.6H2O) in 500 ml of water. Make up to 1 l and mix. 5.7Standard iron solution A Weigh 0,250 g of pure iron to the nearest 0,001 g. Add by small fractions approximately 10 ml of hydrochloric acid (5.3). Oxidise by adding a few drops of hydrogen peroxide (5.4). Decompose the excess hydrogen peroxide by boiling. Cool to room temperature. Transfer quantitatively to a 1 l volumetric flask. Dilute to the mark with water and mix. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12441-5:2003 (E) 5 1 ml of this solution contains 0,250 mg of iron. 5.8Standard iron solution B Transfer exactly 20 ml of standard iron solution A (5.7) to a 100 ml volumetric flask. Dilute to the mark with water and mix. 1 ml of this solution contains 0,050 mg of iron. 5.9Nitric acid, = 1,4 g/ml. 5.10 Aqua regia Mix 3 volumes of hydrochloric acid (5.3) with 1 volume of nitric acid (5.9). 6 Apparatus 6.1 General All glassware used for the preparation of the solutions and for the implementation of the method shall be cleaned with boiling aqua regia (5.10) prior to use. 6.2 Specific equipment In addition to standard laboratory apparatus, a spectrophotometer, set at a wavelength of 425 nm and using 1 cm optical cells shall be used. NOTEThe dilution and aliquot parts defined in this standard only apply if 1cm cells are used. It is necessary to apply the appropriate modifications in the case of cells with other dimensions. 7 Sampling The test sample shall be selected and prepared in accordance with the procedure given in EN 12060. 8 Procedure 8.1 Test portion Weigh 10 g of the test sample to the nearest 0,01 g. 8.2 Blank test Simultaneously with each determination, carry out a blank test using the same quantities of each reagent and following the same procedure. 8.3 Preparation of the test solution 8.3.1Introduce the test portion (8.1) in a 500 ml beaker fitted with a watch-glass and dissolve by carefully adding 50 ml of hydrochloric acid (5.3). Oxidise and complete the dissolution by adding a few drops of hydrogen peroxide (5.4). If dissolution is very difficult, 2 ml of nickel chloride solution (5.6) should be added to expedite the attack. 8.3.2Decompose the excess hydrogen peroxide by boiling. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12441-5:2003 (E) 6 8.3.3For iron contents (mass fractions) equal to or greater than 0,01 % proceed as follows (if less than 0,01 % see 8.3.4): a) cool to room temperature. Transfer quantitatively to a 250 ml volumetric flask. Dilute to the mark with water and mix; b) transfer a 25 ml aliquot to a 100 ml volumetric flask; c) add successively: 1)25 ml of water; 2)5 ml of sulfosalicylic acid (5.5); 3)ammonia solution (5.2) until the solution becomes yellow, then 20 ml in excess; d) cool to room temperature. Dilute to the mark with water and mix. 8.3.4For iron contents (mass fractions) less than 0,01 % proceed as follows: a) evaporate the test portion until a syrupy consistency is obtained; b) cool to room temperature; c) take up with a minimum of water (so as not to exceed 30 ml) and transfer quantitatively to a 100 ml volumetric flask; d) add successively: 1)5 ml of sulfosalicylic acid solution (5.5); 2)ammonia solution (5.2) until the solution has a yellow colour, then 50 ml in excess; e) cool to room temperature. Dilute to the mark and mix. Measure the absorbance of the solutions (see 8.5) after first measuring the calibration graph as in 8.4. 8.4 Calibration graph NOTEThe following is valid for 1 cm cells and for iron contents (mass fractions) of 0 mg, 0,10 mg, 0,25 mg, 0,5 mg and 1,00 mg of iron corresponding to mass fractions in the test portion of 0 %, 0,01 %, 0,025 % 0,05 % and 0,1 % when using the procedure specified in 8.3.3 and 0 %, 0,001 % 0,0025 %, 0,005 % and 0,01 % when using the procedure specified in 8.3.4. It is necessary to apply the appropriate modifications in the case of cells of different dimensions. 8.4.1Introduce into a series of 100 ml volumetric flasks, 0,00 ml, 2,00 ml, 5,00 ml, 10,00 ml and 20,00 ml of standard iron solution B (5.8). 8.4.2Add successively: a) 5 ml of sulfosalicylic acid solution (5.5); b) ammonia solution (5.2) until the solution becomes yellow, then 20 ml in excess. 8.4.3Cool to room temperature. Dilute to the mark with water and mix. 8.4.4Measure the absorbance of each solution against the solution with 0,00 ml standard iron solution B, in 1 cm cells, using the spectrophotometer (6.2) at a wavelength of 425 nm. 8.4.5Produce a calibration graph by plotting the iron content versus the absorbance readings obtained for each calibration standard. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 12441-5:2003 (E) 7 8.5 Spectrophotometric measurement Measure the absorbance of the test solution(s) against the blank solution (8.2) in 1 cm cells using the spectrophotometer (6.2) at a wavelength of 425 nm. 9 Calculation and expression of results Determine from the measured absorbance of the test solution the associated amount of iron from the calibration graph (8.4). If a number of determinations are carried out then the mean of all results shall be calculated by adding the individual results together and dividing by the number of individual results. Results shall be expressed as specified in EN 1179. 10 Test report The test report shall include the following: a) type and identification of the sample; b) test method used, (i.e. reference to this standard); c) iron content, expressed as percentage by mass, giving where possible the results for the individual and the mean values; d) any unusual occurrence during the determination; e) any steps in the procedure beyond those specified in this standard, and any circumstances that may have affected the results; f) date of testing; g) name of the laboratory or testing organisation; h) signature of the laboratory manager or other responsible person. Licensed Copy: sheffieldun sheffieldun, na, Sat Oct 28 07:06:14 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 12441-5:2003 BSI 389 Chiswick High Road London W4 4AL BSI British Standards In
