BS 3338-17-1965 Methods for the sampling and analysis of tin and tin alloys - Method for the determination of cadmium in solders and white metal bearing alloys (photometric method).pdf

1、BRITISH STANDARD BS 3338-17: 1965 Method for The determination of cadmium in solders and white metal bearing alloys (Photometric method) Methods for the sampling and analysis of tin and tin alloysBS3338-17:1965 This British Standard, having been approved by the Non-ferrous Metals Industry Standards

2、Committee and endorsed by the Chairman of theEngineering Divisional Council, was published under theauthority of the General Council on 18March1965 BSI 12-1999 The following BSI references relate to the work on this standard: Committee references NFE/27, NFE/27/1 Draft for comment D63/4041 ISBN 0 58

3、0 03177 2 Co-operating organizations The Non-ferrous Metals Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: The Government departments and scie

4、ntific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Aluminium Federation Institution of Mining and Metallurgy Association of Bronze and Brass Fo

5、unders Institution of Production Engineers Association of Consulting Engineers Institution of Structural Engineers British Bronze and Brass Ingot Manufacturers Lead Development Association Association Light Metal Founders Association British Electrical and Allied Manufacturers London Metal Exchange*

6、 Association* Magnesium Industry Council British Lead Manufacturers Association Ministry of Aviation British Non-ferrous Metals Federation Ministry of Defence, Army Department* British Non-ferrous Metals Research Ministry of Defence, Naval Department* Association* Ministry of Transport Copper Develo

7、pment Association National Brassfoundry Association Crown Agents for Oversea Governments and Non-ferrous Metal Stockists Administrations Post Office* Electric Cable Makers Federation Royal Institute of British Architects High Commission of India Society of British Aerospace Companies Ltd. High Condu

8、ctivity Copper Association Society of Motor Manufacturers and Traders Institute of British Foundrymen Ltd. Institute of Metals Tin Research Institute* Institution of Mechanical Engineers Zinc Development Association (Automobile Division) Individual manufacturer British Railways Board London Transpor

9、t Board British Tin Box Manufacturers Federation Solder Makers Association Cable Makers Association Tinplate Conference (1925) Electronic Engineering Association Tin Producers Association Gas Council White Metal Bearing Manufacturers Institution of Gas Engineers Individual firms Amendments issued si

10、nce publication Amd. No. Date CommentsBS3338-17:1965 BSI 12-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii Introduction 1 Apparatus 1 Solutions required 1 Sampling 1 Procedure 2 Calibration 2BS3338-17:1965 ii BSI 12-1999 Foreword This standard makes reference to the f

11、ollowing British Standards: BS 219, Soft solders. BS 3252, Ingot tin. BS 3332, White metal bearing alloy ingots. BS 3338, Methods for the sampling and analysis of tin and tin alloys Part12:Sampling of solders Part 14: Sampling of white metal bearing alloy ingots. This method for the determination of

12、 cadmium in solders and white metal bearing alloys is the seventeenth of a series of methods which will form a complete British Standard under the collective title “Methods for the sampling and analysis of tin and tin alloys”, each method being published as a separate part. The preparation of this s

13、eries of methods has been authorized by the Non-ferrous Metals Industry Standards Committee as part of a general programme for the standardization of methods for the sampling and analysis of non-ferrous metals. Other methods in the series are as follows: Part 1: Sampling of ingot tin; Part 2: Determ

14、ination of tin in ingot tin; Part 3: Determination of antimony in ingot tin; Part 4: Determination of copper in ingot tin and tin-lead solders; Part 5: Determination of lead in ingot tin and tin-antimony solders; Part 6: Determination of copper in high purity ingot tin; Part 7: Determination of silv

15、er in solders; Part 8: Determination of bismuth in ingot tin, tin-lead solders and white metal bearing alloys; Part 9: Determination of arsenic in ingot tin, solders and white metal bearing alloys; Part 10: Determination of iron in ingot tin, tin-lead solders and white metal bearing alloys; Part 11:

16、 Determination of tin in solders; Part 12: Sampling of solders; Part 13: Determination of antimony in solders and white metal bearing alloys; Part 14: Sampling of white metal bearing alloy ingots; Part 15: Determination of copper and lead in white metal bearing alloys; Part 16: Determination of tin

17、in white metal bearing alloys. The complete British Standard methods will be found suitable for the grades of metals covered by BS3252, “Ingot tin”, BS219, “Soft solders”, and BS3332, “White metal bearing alloy ingots”. In the methods for determining impurities, sample weights and aliquots have been

18、 chosen to cover the range of impurity content usually found in commercial tin ingots, solders and white metal bearing alloy ingots. For amounts of impurity outside this range, sample weights or aliquots should be adjusted accordingly. The methods have been found to give reliable and reproducible re

19、sults, and, while in some instances they may appear to be lengthy, it should be realized that they are put forward as “referee” methods to be used in cases of dispute.BS3338-17:1965 BSI 12-1999 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of Br

20、itish Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages1and 2 and a back cover. This standard has b

21、een updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS3338-17:1965 BSI 12-1999 1 Introduction a) Principle. Cadmium is determined photometrically with dithizone after removal of interfering element

22、s. b) Range. Up to 0.12 per cent cadmium. c) Reproducibility. 10 per cent of cadmium present. Apparatus a) All volumetric glassware used shall be of ClassA accuracy as defined in the appropriate British Standards, or where no British Standard exists, as described in the National Physical Laboratory

23、Publication “Volumetric tests on volumetric glassware”. b) Any instrument suitable for measuring the optical density of the solution at a wavelength of510m4 may be used together with4cm or1cm cells (Note1). c) Alternatively, when a filter photometer of the balanced two cell type is used, the followi

24、ng conditions have been found suitable: Tungsten lamp Ilford 604 or equivalent filters 4 cm or 1 cm cells. Solutions required All reagents shall be of the highest purity obtainable and distilled water 1)shall be used throughout. Solutions shall be freshly prepared and, where necessary, filtered. Sta

25、ndard cadmium (1mlN 0.5mg of cadmium). Dissolve0.250g of cadmium in10ml of nitric acid(20 per cent v/v), transfer to a500ml volumetric flask and dilute to the mark. Standard cadmium (1mlN 0.005mg of cadmium). Transfer5ml of standard cadmium solution(1mlN 0.5mg of cadmium) to a500ml volumetric flask

26、and dilute to the mark. Bromine water (saturated). To100ml of water add5ml of bromine, shake and allow to stand until saturated. Bromine-hydrobromic acid. To 90ml of hydrobromic acid (sp. gr. 1.461.49) add carefully10ml of bromine. Brucine sulphate (2 per cent w/v). Dissolve2g of brucine sulphate by

27、 warming in100ml of acetic acid (5 per cent v/v). Cupferron (2 per cent w/v). Dissolve2g of cupferron in water and dilute to100ml. Dithizone solution. Dissolve25mg of dithizone in25ml of chloroform. Shake twice with100ml of ammonia solution (2 per cent v/v) in a large separating funnel and discard t

28、he chloroform layer. Make the aqueous solution just acid by addition of hydrochloric acid (sp. gr. 1.161.18). Add250ml of carbon tetrachloride, shake, and separate the carbon tetrachloride layer. Repeat this step. Combine the two carbon tetrachloride extracts, wash with water and store in a dark bot

29、tle. Hydrochloric acid (50 per cent v/v). Dilute50ml of hydrochloric acid (sp. gr. 1.161.18) to100ml. Hydrochloric acid (10 per cent v/v). Dilute10ml of hydrochloric acid (sp. gr. 1.161.18) to100ml. Hydrochloric acid (5 per cent v/v). Dilute5ml of hydrochloric acid (sp. gr. 1.161.18) to100ml. Hydrox

30、yammonium chloride (10 per cent w/v). Dissolve10g of hydroxyammonium chloride in water and dilute to100ml. Potassium iodide (10 per cent w/v). Dissolve10g of potassium iodide in water and dilute to100ml. Sodium hydroxide (20 per cent w/v). Dissolve20g of sodium hydroxide in water and dilute to100ml.

31、 Sodium tartrate (20 per cent w/v). Dissolve20g of sodium tartrate in water and dilute to100ml. Methyl red (0.02 per cent w/v). Dissolve0.02g of methyl red (water soluble) in water and dilute to100ml. Sampling Recommended methods of obtaining a suitable sample for the analytical procedure given belo

32、w are described in BS3338, Part 12, “Sampling of solders” and Part14, “Sampling of white metal bearing alloy ingots”. 1) Water demineralized by ion exchange may be used if it is of equivalent quality.BS3338-17:1965 2 BSI 12-1999 Procedure Weigh 1.25g of sample and transfer to a150ml beaker. Add20ml

33、of the bromine-hydrobromic acid and5ml of perchloric acid (sp. gr. 1.54). Evaporate to fuming, and if the solution is cloudy add a further quantity of the bromine-hydrobromic acid. Repeat until the solution is clear, indicating complete removal of tin and antimony (Note2). Cool, dilute, transfer to

34、a250ml volumetric flask and dilute to the mark. Transfer a5ml aliquot to a100ml separating funnel, add2ml of sodium tartrate solution (20 per cent), one drop of methyl red indicator, make just alkaline with sodium hydroxide solution (20 per cent) and acidify with2ml of acetic acid (glacial). Dilute

35、to30ml, add5ml of cupferron solution (2 per cent) and shake with10ml of chloroform. Allow to separate and discard the chloroform layer. Repeat the addition of cupferron and extraction with chloroform until no precipitate appears on the addition of the cupferron solution. To the aqueous solution rema

36、ining in the funnel add1ml of bromine water and, after standing for one minute, extract the excess of bromine by shaking with two5ml portions of chloroform. Add1ml of hydroxyammonium chloride solution(10per cent). Then add5ml of potassium iodide solution (10 per cent) and5ml of brucine solution (2 p

37、er cent). Extract three times with15ml portions of chloroform and collect the chloroform extracts in a200ml separating funnel. Discard the aqueous layer in the first funnel. Shake the extracts in the second funnel with20ml of hydrochloric acid(5 per cent). Run off the chloroform layer into another f

38、unnel and shake with a further10ml of hydrochloric acid (5 per cent). Discard the chloroform layer and combine the two hydrochloric acid extracts. Add 30ml of sodium hydroxide solution(20percent) and20ml of the dithizone solution and shake for1minute. Remove any droplets of water from the stem of th

39、e funnel by inserting a roll of filter paper 2) . Remove the paper and run off the carbon tetrachloride layer into a small stoppered bottle. Measure the optical density of the solution at20 1 C using the conditions specified under “Apparatus” and using carbon tetrachloride in the reference cell. Car

40、ry out simultaneously a blank determination on the reagents. Follow the same procedure without the sample and use the same quantity of reagents. Deduct the blank reading and calculate the percentage of cadmium in the sample by reference to the appropriate calibration graph. Calibration Transfer to a

41、 series of100ml separating funnels the following amounts of standard cadmium solution(1mlN 0.005 mg of cadmium): for the4cm cell0.5, 1.0, 1.5, 2.0ml for the1cm cell1.5, 3.0, 4.5, 6.0ml. Dilute to30ml, and continue from Paragraph2 of the procedure. Prepare calibration graphs by plotting optical densi

42、ties against the weight of cadmium in the various aliquots, after deduction of the blank reading. NOTE 1A 4cm cell should be used for cadmium contents up to0.04 per cent and a1cm cell for cadmium contents up to0.12 per cent. NOTE 2In the presence of more than10per cent of lead remove the bulk of lea

43、d as follows: Cool, dilute with20ml of water, add5ml of hydrochloric acid(50per cent) and cool in ice-water. Filter off the lead chloride on to a sintered glass filter (Porosity4) and wash with a little cold hydrochloric acid (10 per cent). Evaporate the filtrate to fumes of perchloric acid and cont

44、inue as in the procedure. 2) Whatman No. 41 is suitable.blankBS 3338-17: 1965 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the internation

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