1、BSI Standards PublicationBS EN ISO 4946:2016Steel and cast iron Determination of copper 2,2-Biquinoline spectrophotometric methodBS EN ISO 4946:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 4946:2016.It supersedes BS 6200-3.12.2:1985 which is withdraw
2、n.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/102, Methods of Chemical Analysis for Iron and Steel.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovis
3、ions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 81538 6ICS 77.080.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published u
4、nder the authority of theStandards Policy and Strategy Committee on 31 March 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 4946 March 2016 ICS 77.080.01 Supersedes EN 24946:1990English Version Steel and cast ir
5、on - Determination of copper - 2,2-Biquinoline spectrophotometric method (ISO 4946:2016)Aciers et fontes - Dtermination du cuivre - Mthode spectrophotomtrique au 2,2-biquinolyle (ISO 4946:2016) Stahl und Gusseisen - Bestimmung des Kupferanteils - Spektrophotometrisches Verfahren mit 2,2-Biquinoline
6、(ISO 4946:2016) This European Standard was approved by CEN on 21 November 2015. 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 bi
7、bliographical references concerning such national standards may be obtained on application to the CEN-CENELEC 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 resp
8、onsibility 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, Former Yugoslav Re
9、public of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NOR
10、MALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 4946:2016 EBS EN ISO 4946:2016EN ISO 4946:2016 (E) 3 European forew
11、ord This document (EN ISO 4946:2016) has been prepared by Technical Committee ISO/TC 17 “Steel” in collaboration with Technical Committee ECISS/TC 102 “Methods of chemical analysis for iron and steel” the secretariat of which is held by SIS. This European Standard shall be given the status of a nati
12、onal standard, either by publication of an identical text or by endorsement, at the latest by September 2016, and conflicting national standards shall be withdrawn at the latest by September 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject of
13、patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 24946:1990. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN
14、-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungar
15、y, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 4946:2016 has been approved by CEN as EN ISO 4946:2016 without any modif
16、ication. BS EN ISO 4946:2016ISO 4946:2016(E)Foreword iv1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 26 Sampling 27 Procedure. 37.1 Test portion 37.2 Blank test . 37.3 Determination . 37.3.1 Preparation of the test solution 37.3.2 Colour development 37.3.3 Preparation of
17、the compensating solution 47.3.4 Spectrophotometric measurement 47.4 Establishment of the calibration graph . 47.4.1 Preparation of the calibration solutions 47.4.2 Spectrophotometric measurement 47.4.3 Calibration graph . 48 Expression of results 59 Precision . 59.1 General 59.2 Repeatability 69.3
18、Reproducibility 610 Test report . 6Annex A (informative) Additional information on the international interlaboratory test 7Annex B (informative) Graphical representation of precision data 8Bibliography 9 ISO 2016 All rights reserved iiiContents PageBS EN ISO 4946:2016ISO 4946:2016(E)ForewordISO (the
19、 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 committe
20、e 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 electrotechni
21、cal standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in
22、 accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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. D
23、etails of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an
24、 endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The committee
25、responsible for this document is ISO/TC 17, Steel, Subcommittee SC 1, Methods of determination of chemical composition.This second edition cancels and replaces the first edition (ISO 4946:1984), which has been technically revised to include the following changes: correction of the specification of p
26、lotting the calibration graphs in 7.4.3; editorial revision of some items in accordance with the updated ISO/IEC Directives, Part 2.iv ISO 2016 All rights reservedBS EN ISO 4946:2016INTERNATIONAL STANDARD ISO 4946:2016(E)Steel and cast iron Determination of copper 2,2-Biquinoline spectrophotometric
27、method1 ScopeThis International Standard specifies a spectrophotometric method for the determination of copper in steel and cast iron by 2,2-biquinoline.The method is applicable to the determination of copper mass fraction in the range of 0,02 % and 5 %.2 Normative referencesThe following documents,
28、 in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 648, Laboratory glassware Si
29、ngle-volume pipettesISO 1042, Laboratory glassware One-mark volumetric flasksISO 3696, Water for analytical laboratory use Specification and test methodsISO 14284, Steel and iron Sampling and preparation of samples for the determination of chemical composition3 PrincipleDissolution of a test portion
30、 in appropriate acids.Fuming with perchloric acid to remove hydrochloric and nitric acids and dehydrate silicic acid.Reduction of copper(II) to copper(I) in hydrochloric acid solution by means of ascorbic acid. Formation of a coloured compound of copper(I) with 2,2-biquinoline.Spectrophotometric mea
31、surement at a wavelength of about 545 nm.4 ReagentsDuring the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only grade 2 water as specified in ISO 3696.4.1 High-purity iron, containing copper 0,001 % (mass fraction) or less.4.2 Hydrochloric acid, approximate
32、ly 1,19 g/ml.4.3 Nitric acid, approximately 1,40 g/ml.4.4 Perchloric acid, approximately 1,54 g/ml.WARNING Perchloric acid vapour might cause explosions in the presence of ammonia, nitrous fumes or organic material in general. ISO 2016 All rights reserved 1BS EN ISO 4946:2016ISO 4946:2016(E)Perchlor
33、ic acid, approximately 1,67 g/ml, may also be used. 100 ml of perchloric acid, approximately 1,54 g/ml is equivalent to 79 ml of perchloric acid, approximately 1,67 g/ml.4.5 Perchloric acid, approximately 1,54 g/ml, diluted 1 + 7.4.6 Dimethylformamide (N,N-dimethylformamide), approximately 0,944 g/m
34、l.WARNING Dimethylformamide is a hazardous substance and can cause birth defects. It should be handled with safety gloves in a fume hood.4.7 Ascorbic acid, 200 g/l solution.Dissolve 20 g of ascorbic acid in water, dilute to 100 ml with water and mix.Prepare this solution immediately before use.4.8 2
35、,2-Biquinoline solution.Dissolve 0,60 g of 2,2-biquinoline (cuproine, 2,2-diquinolyl) in dimethylformamide (4.6), dilute to 1 l with the same dimethylformamide and mix.Keep this solution in a dark-coloured glass flask and protect it from the light.4.9 Copper standard solution, 1 g/l.Weigh, to the ne
36、arest 0,001 g, 1,000 g of high purity copper and dissolve in the minimum of nitric acid (4.3).Heat to boiling to remove nitrous fumes. Cool and transfer the solution quantitatively to a 1 000 ml one-mark volumetric flask, dilute to the mark with water and mix.1 ml of this standard solution contains
37、1 mg of copper.4.10 Copper standard solution, 0,05 g/l.Transfer 25,0 ml of the copper standard solution (4.9) to a 500 ml one-mark volumetric flask, dilute to the mark with water and mix.1 ml of this standard solution contains 0,05 mg of copper.5 ApparatusAll volumetric glassware shall be Class A, i
38、n accordance with ISO 648 and ISO 1042.Ordinary laboratory apparatus and the following shall be used.Spectrophotometer, suitable for measuring the absorbance of the solution at a wavelength of 545 nm with cells of 2 cm or 4 cm optical path length.6 SamplingCarry out sampling in accordance with ISO 1
39、4284 or appropriate national standards for steel and cast iron.2 ISO 2016 All rights reservedBS EN ISO 4946:2016ISO 4946:2016(E)7 Procedure7.1 Test portionWeigh, to the nearest 0,001 g, approximately 0,5 g of the test sample.7.2 Blank testIn parallel with the determination and following the same pro
40、cedure, carry out two blank tests using the same quantities of all the reagents but using, to the nearest 0,001 g, approximately 0,5 g of pure iron (4.1) instead of test portion.7.3 Determination7.3.1 Preparation of the test solutionIntroduce the test portion (7.1) into a 250 ml beaker. Add 10 ml of
41、 hydrochloric acid (4.2) and 5 ml of nitric acid (4.3). Cover the beaker with a watch-glass and heat until acids action ceases.NOTE For samples of high chromium content, first dissolve in hydrochloric acid (4.2) and then, when all effervescence has ceased, oxidize by adding nitric acid (4.3), drop b
42、y drop.Add 10 ml of perchloric acid (4.4) and evaporate to fuming. Continue fuming for 3 min.Cool, dissolve the salts with 20 ml of water, transfer the solution quantitatively to a one-mark volumetric flask of suitable capacity (see Table 1), dilute to the mark with water and mix.Filter by decantati
43、on through a dry filter to remove any residue or precipitate, e.g. graphite, silica, tungstic acid. Collect the filtrate in a dry beaker, discarding the first fractions of the filtrate.7.3.2 Colour developmentTake an aliquot portion, according to the expected copper content, as indicated in Table 1.
44、Table 1 Volume of test solution and aliquot portionCopper content Volume of test solutionVolume of aliquot portion% (mass fraction) ml ml0,02 to 0,3 0,3 to 0,6 0,6 to 1,5 1,5 to 5,0100 100 250 50010 5 5 5Transfer the selected aliquot portion to a 50 ml one-mark volumetric flask. If the aliquot porti
45、on is 5 ml, add 5 ml of perchloric acid (4.5).Add, in the following order, shaking after each addition: 5 ml of ascorbic acid solution (4.7); 25 ml of 2,2-biquinoline solution (4.8).Dilute to the mark with water and mix. Cool for 5 min in a water-bath at about 20 C.Finally, readjust the volume and m
46、ix again. ISO 2016 All rights reserved 3BS EN ISO 4946:2016ISO 4946:2016(E)7.3.3 Preparation of the compensating solutionTransfer an aliquot portion of the test solution (7.3.1) similar to the aliquot portion for the development of the colour (7.3.2) to a 50 ml one-mark volumetric flask. If the aliq
47、uot portion is 5 ml, add 5 ml of perchloric acid (4.5).Add, in the following order, shaking after each addition: 5 ml of ascorbic acid solution (4.7); 25 ml of dimethylformamide solution (4.6).Dilute to the mark with water and mix. Cool for 5 min in a water-bath at about 20 C.Finally, readjust the v
48、olume and mix again.7.3.4 Spectrophotometric measurementCarry out the spectrophotometric measurement of the test solution (7.3.1) at a wavelength of about 545 nm, in a cell of 2 cm optical path length, after adjusting the spectrophotometer (Clause 5) to zero absorbance in relation to the compensatin
49、g solution (7.3.3).For copper contents below 0,06 % (mass fraction), 4 cm cells may be used if the sensitivity of the spectrophotometer is not sufficient with 2 cm cells.7.4 Establishment of the calibration graph7.4.1 Preparation of the calibration solutionsInto each of a series of 100 ml beakers, add 0,5 g 0,01 g of high purity iron (4.1) and 10 ml of hydrochloric acid (4.2). Cover with a watch-glass and heat gently until dissolved, then oxidize by adding nitric acid (4.3) drop by drop. Add the followi
