1、BSI Standards PublicationBS ISO 4939:2016Steel Determination ofnickel Dimethylglyoximespectrophotometric methodBS ISO 4939:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 4939:2016.It supersedes BS 6200-3.20.3:1985 which is withdrawn.The UK participation i
2、n 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 necessaryprovisions of a contract. User
3、s are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 81536 2ICS 77.080.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of th
4、eStandards Policy and Strategy Committee on 29 February 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 4939:2016 ISO 2016Steel Determination of nickel Dimethylglyoxime spectrophotometric methodAciers Dtermination du nickel Mthode spectrophotomtrique la dimthylg
5、lyoximeINTERNATIONAL STANDARDISO4939Second edition2016-02-01Reference numberISO 4939:2016(E)BS ISO 4939:2016ISO 4939:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may b
6、e reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the re
7、quester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 4939:2016ISO 4939:2016(E)Foreword iv1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 26 Sampling 27 Procedure.
8、 27.1 Test portion 27.2 Blank test . 27.3 Determination . 27.3.1 Preparation of the test solution 27.3.2 Colour development 37.3.3 Preparation of the compensating solution 37.3.4 Spectrophotometric measurement 37.4 Establishment of the calibration curve 37.4.1 Preparation of the calibration solution
9、s 37.4.2 Spectrophotometric measurement 47.4.3 Calibration curves 48 Expression of results 49 Precision . 59.1 General . 59.2 Repeatability . 59.3 Reproducibility . 510 Test report . 5Annex A (informative) Additional information on the international interlaboratory test 7Annex B (informative) Graphi
10、cal representation of precision data 8Bibliography 9 ISO 2016 All rights reserved iiiContents PageBS ISO 4939:2016ISO 4939:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Interna
11、tional 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
12、ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, P
13、art 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in 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
14、 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. Details 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 re
15、ceived (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 endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs a
16、dherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 1, Methods of determination of chemical compound.This second edition cancels and replac
17、es the first edition (ISO 4939:1984), which has been technically revised. In particular, the specification of plotting of the calibration graphs shown in 7.4.3 has been corrected.iv ISO 2016 All rights reservedBS ISO 4939:2016INTERNATIONAL STANDARD ISO 4939:2016(E)Steel Determination of nickel Dimet
18、hylglyoxime spectrophotometric method1 ScopeThis International Standard specifies a spectrophotometric method for the determination of nickel in steel using dimethylglyoxime. The method is applicable to the determination of nickel mass fractions in the range of 0,10 % and 2,0 %. Cobalt, copper and m
19、anganese can cause interferences (see 7.3.2).2 Normative referencesThe following documents, 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
20、the referenced document (including any amendments) applies.ISO 648, Laboratory glassware Single-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 sa
21、mples for the determination of chemical composition3 PrincipleDissolution of a test portion in hydrochloric, nitric and perchloric acids.Formation of a coloured complex of nickel(lll) with dimethylglyoxime in ammoniacal solution containing iodine and potassium iodide.Spectrophotometric measurement a
22、t a wavelength of about 535 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 Acid mixture.Mix two volumes of hydrochloric acid, approximately 1,19 g/ml, one volume of nitric acid, approxima
23、tely 1,40 g/ml and two volumes of water.4.2 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.Perchloric acid, approximately 1,67 g/ml, may also be used. 100 ml of perchloric acid, a
24、pproximately 1,54 g/ml is equivalent to 79 ml of perchloric acid, approximately 1,67 g/ml. ISO 2016 All rights reserved 1BS ISO 4939:2016ISO 4939:2016(E)4.3 Ammonium citrate, 250 g/l solution.Dissolve 250 g of citric acid monohydrate (C6H8O7H2O) in 250 ml of ammonia solution, approximately 0,91 g/ml
25、, cool, dilute to 1 l with water and mix.4.4 Iodine, 12,7 g/l solution.Dissolve 25 g of potassium iodide and 12,7 g of iodine in the minimum volume of water. Dilute to 1 l with water and mix.4.5 Dimethylglyoxime, 1 g/l solution.Dissolve 1 g of dimethylglyoxime in 500 ml of ammonia solution, approxim
26、ately 0,91 g/ml, dilute to 1 l with water and mix.4.6 Ammonia solution, approximately 0,91 g/ml, diluted 1 + 1.4.7 Nickel standard solution, 0,5 g/l.Weigh, to the nearest 0,001 g, 0,500 g of high purity nickel purity 99,95 % (mass fraction) and dissolve in 20 ml of nitric acid, approximately 1,40 g/
27、ml, diluted 2 + 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 0,5 mg of nickel.5 ApparatusAll volumetric glassware shall be Class A, in a
28、ccordance 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 535 nm with cells of 1 cm or 4 cm optical path length.6 SamplingCarry out sampling in accordance with ISO 1428
29、4 or appropriate national standards for steel.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 procedure, carry out a blank test using the same quantities of all the reagents excep
30、t the 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 acid mixture (4.1) and 10 ml of perchloric acid (4.2). Cover the beaker with a watch-glass and heat until acids action ceases.2 ISO 2016 All rights reservedBS
31、 ISO 4939:2016ISO 4939:2016(E)Evaporate until white fumes of perchloric acid appear and continue fuming at a temperature suitable to maintain a steady reflux of perchloric acid fumes on the walls of the beaker for at least 3 min and until any chromium is oxidized to chromate. Remove from the source
32、of heat and allow to cool.Add 50 ml of water, heat to dissolve salts, cool and transfer quantitatively to a 250 ml one-mark volumetric flask. Dilute to the mark with water and mix.Filter by decantation through a dry filter to remove any residue or precipitate and collect the filtrate in a dry beaker
33、, discarding the first fractions of the filtrate.7.3.2 Colour developmentTransfer a 25 ml aliquot portion of the test solution (7.3.1) to a 100 ml one-mark volumetric flask.If the test solution (7.3.1) contains cobalt, copper or manganese, the aliquot portion taken should be such that the respective
34、 contents of these elements do not exceed the following limits: cobalt, 5 mg; copper, 0,5 mg; manganese, 1 mg.Add 20 ml of the ammonium citrate solution (4.3), mix, then add 3 ml of the iodine solution (4.4) and mix again. Allow to stand for 5 min.Add 20 ml of the dimethylglyoxime solution (4.5), di
35、lute to the mark with water and mix.Allow to stand for at least 10 min and at most 20 min at a temperature of 20 C 5 C.7.3.3 Preparation of the compensating solutionTransfer a 25 ml aliquot portion of the test solution (7.3.1) to another 100 ml volumetric flask.Add 20 ml of the ammonium citrate solu
36、tion (4.3), mix, then add 3 ml of the iodine solution (4.4) and mix again. Allow to stand for 5 min.Add 20 ml of the ammonia solution (4.6), dilute to the mark with water and mix.Allow to stand for at least 10 min and at most 20 min at a temperature of 20 C 5 C.7.3.4 Spectrophotometric measurementCa
37、rry out the spectrophotometric measurement of the test solution at a wavelength of about 535 nm in a cell of appropriate optical path length (1 cm or 4 cm) after having adjusted the spectrophotometer (Clause 5) to zero absorbance with the corresponding compensating solution (7.3.3).7.4 Establishment
38、 of the calibration curve7.4.1 Preparation of the calibration solutionsIntroduce into a series of 250 ml beakers containing 10 ml of the acid mixture (4.1) and 10 ml of perchloric acid (4.2), the volumes of the nickel standard solution (4.7) indicated in Table 1, as appropriate for the expected nick
39、el content.Treat as described in 7.3.1 and 7.3.2, using the calibration solution “0” as the compensating solution. ISO 2016 All rights reserved 3BS ISO 4939:2016ISO 4939:2016(E)Table 1 Composition of the calibration solutions and cell optical path lengthNickel content% (mass fraction)Nickel standard
40、 solution (4.7)mlNickel concentration in the solution for spectrophotometric measurement g/mlCell optical path lengthcm0,1 to 0,50 1,0 2,0 3,0 4,0 5,00 0,5 1,0 1,5 2,0 2,540,5 to 2,00 4,0 6,0 8,0 10,0 14,0 16,0 20,00 2,0 3,0 4,0 5,0 7,0 8,0 10,017.4.2 Spectrophotometric measurementCarry out spectrop
41、hotometric measurements of each solution at a wavelength of about 535 nm after having adjusted the spectrophotometer (Clause 5) to zero absorbance with the calibration solution “0” (7.4.1) used as the compensating solution.7.4.3 Calibration curvesFor each range of nickel content and appropriate opti
42、cal path length of the cells (see Table 1), establish the corresponding calibration graph by plotting the net absorbance values against the nickel concentrations, expressed in micrograms per millilitre, in the calibration solutions.8 Expression of resultsConvert the absorbance (7.3.4) into the corre
43、sponding concentration, expressed in micrograms of nickel per millilitre, in the colour-developed test solution by using the calibration curve (7.4.3).The nickel content (CNi), expressed as a (%) mass fraction, is given by Formula (1), Formula (2) and Formula (3):CVVVmNi Ni Nit=()10601110100 (1)CmNi
44、 Ni Ni=()10611025025100100 (2)CmNi Ni Ni=()10110(3)wherem is the mass of the test portion (7.1), in grams;V0is the volume of the test solution (7.3.1), in millilitres;4 ISO 2016 All rights reservedBS ISO 4939:2016ISO 4939:2016(E)V1is the volume of the aliquot portion (7.3.2), in millilitres,;Vtis th
45、e volume of the colour-developed test solution (7.3.2), in millilitres;Ni0is the concentration of nickel in the blank test solution (corrected for its compensating solution), expressed in micrograms per millilitre;Ni1is the concentration of nickel in the test solution (corrected for its compensating
46、 solution), expressed in micrograms per millilitre.9 Precision9.1 GeneralA planned trial of this method was carried out by five laboratories, at six levels of nickel, each laboratory making six determinations of nickel at each level.The results obtained were treated statistically in accordance with
47、ISO 5725:19861.The obtained data showed a logarithmic relationship between nickel content and repeatability and reproducibility of the test results. Table 2 shows the smoothed data derived from these relationships. The graphic presentation of the precision data is given in Annex B.Table 2 Repeatabil
48、ity and reproducibility limitsNickel content% (mass fraction)Repeatability limitrReproducibility limitR0,1 0,2 0,5 1,0 2,00,010 0,013 0,019 0,025 0,0340,013 0,018 0,027 0,038 0,0539.2 RepeatabilityThe difference between two single and independent results obtained on identical test material by one an
49、alyst using the same apparatus within a short time interval in the normal and correct operation of the test method will exceed the repeatability, r, only in one case in 20 cases.9.3 ReproducibilityThe difference between two single and independent results obtained by two operators working in different laboratories on identical test material in the normal and correct operation of the test method will exceed the reproducibility, R, only in one case in 20 cases.10 Test reportT
