1、BRITISH STANDARD BS3907-13: 1972 Method for The determination of tin in magnesium and magnesium alloys (Photometric method) Methods for the analysis of magnesium and magnesium alloysBS3907-13:1972 This BritishStandard, having been approved by the Non-ferrous Metals Industry Standards Committee, was
2、published under the authorityofthe Executive Boardon 14September1972 BSI12-1999 The following BSI references relate to the work on this standard: Committee references NFE/23 andNFE/23/4 Draft for comment71/40317 ISBN 0 580 07247 9 Co-operating organizations The Non-ferrous Metals Industry Standards
3、Committee, under whose supervision this BritishStandard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Aluminium Federation Association of Bronze and Brass Founders British Bronze and Brass Ingot Manufacturers Associat
4、ion British Lead Manufacturers Association British Non-ferrous Metals Federation British Non-ferrous Metals Federation High Conductivity Copper Group British Non-ferrous Metals Research Association* Copper Development Association Department of Trade and Industry (Marine Division) Electric Cable Make
5、rs Confederation Institute of British Foundrymen Institute of Metals Institution of Mechanical Engineers (Automobile Division) Institution of Mining and Metallurgy Institution of Production Engineers Institution of Structural Engineers Lead Development Association Light Metal Founders Association Lo
6、ndon Metal Exchange Magnesium Industry Council* Ministry of Defence (Army)* Ministry of Defence (Navy) National Brassfoundry Association Non-ferrous Metal Stockists* Post Office Royal Institute of British Architects Society of Motor Manufacturers and Traders Ltd.* Tin Research Institute Zinc Develop
7、ment Association Individual manufacturers The Government department and scientific 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 thisBritishStandard: Department of Trad
8、e and Industry Department of Trade and Industry Laboratory of the Government Chemist Institute of Sheet Metal Engineering Individual analysts Amendments issued since publication Amd. No. Date CommentsBS3907-13:1972 BSI 12-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii
9、 1 Introduction 1 2 Apparatus 1 3 Solutions required 1 4 Sampling 1 5 Procedure 1 6 Calibration 2 7 Notes 2BS3907-13:1972 ii BSI 12-1999 Foreword This standard makes reference to the following BritishStandards: BS1499, Sampling non-ferrous metals. BS3978, Water for laboratory use. This method for th
10、e photometric determination of tin in magnesium and magnesium alloys is the thirteenth of a series which will form a complete BritishStandard under the collective title “Methods for the analysis of magnesium and magnesium alloys” each being published as a separate part. Other methods in the series a
11、re as follows: Part1: Aluminium (gravimetric method); Part2: Iron (photometric 1 : 10 phenanthroline method); Part3: Copper (photometric method); Part4: Manganese (photometric periodate method); Part5: Manganese (photometric periodate method) (low contents); Part6: Zirconium (photometric method); Pa
12、rt7: Nickel (photometric method); Part8: Total rare earths (gravimetric method); Part9: Zinc (ion-exchange-volumetric EDTA method); Part10: Manganese in magnesium alloys containing zirconium, rare earths or thorium (photometric method); Part11: Silicon in magnesium and magnesium alloys; Part12: Alum
13、inium in magnesium and magnesium alloys (photometricmethod). The preparation of this series 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. The
14、 methods have been found to give reliable and reproducible results and while in some instances they may appear to be lengthy, it should be appreciated that they are primarily intended as “referee” methods to be used in cases of dispute. A British Standard does not purport to include all the necessar
15、y provisions of a contract. Users of British 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, pagesi andii, pages1 and
16、2 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS3907-13:1972 BSI 12-1999 1 1 Introduction 1.1 Principle. Tin as the tin-quercetin complex isseparated into isobu
17、tyl methyl ketone(4-methylpentan2-one) and the determination is completed photometrically. 1.2 Range. The method is recommended for tin contents up to0.08%. 1.3 Reproducibility. Experiments have been carried out independently by a number of analysts using this method. The degree of reproducibility t
18、hat can be expected is shown by the following analysis of the results obtained. 2 Apparatus 2.1 Class A volumetric glassware complying with theappropriate BritishStandards shall be used throughout. 2.2 Any instrument suitable for measuring the optical density of the solution at a wavelength of440nm
19、may be used with a1cm cell. Alternatively, when a filter photometer of the balanced two-cell type is used, the following conditions have been found suitable: Mercury vapour lamp; Ilford601 or equivalent filter; 1cm cell. 3 Solutions required All reagents shall be of the highest purity obtainable and
20、 either distilled or demineralized water complying with BS3978 1)shall be used throughout. Solutions shall be freshly prepared and where necessary filtered. Standard tin (1mlN 0.05mg of tin). Dissolve0.5g of high purity tin by warming with a mixture of10ml of sulphuric acid(50%) and10ml of nitricaci
21、d(50%). When the sample has dissolved evaporate to fumes of sulphuric acid. Allow to cool, add190ml of sulphuric acid(50%) transfer to a1litre volumetric flask, dilute to the mark and mix. Transfer10ml of this solution to a100ml volumetric flask, dilute to the mark with sulphuric acid(10%) and mix.
22、Standard tin (1ml N 0.01mg of tin). Transfer20ml of standard tin solution(1mlN 0.05mg of tin) to a100ml volumetric flask, dilute to the mark with sulphuric acid(10%) and mix. Ascorbic acid (2% w/v), Dissolve2g of ascorbic acid in water, dilute to100ml and mix. This solution should be prepared immedi
23、ately before use. Quercetin (0.1% w/v). Dissolve0.2g of quercetin(3,3,4,5,7 pentahydroxyflavone) in60ml of ethanol(95%), heating gently to dissolve. Cool, add5ml of hydrochloric acid (sp.gr.1.161.18), dilute to200ml with ethanol(95%) and mix. Filter if necessary. Nitric acid (50%v/v). Dilute500ml of
24、 nitric acid (sp. gr.1.42) to1litre and mix. Sulphuric acid (50%v/v). To400ml of water, add cautiously500ml of sulphuric acid (sp. gr.1.84), mix. Cool, dilute to1litre and mix. Sulphuric acid (10%v/v). To400ml of water, add cautiously100ml of sulphuric acid (sp. gr.1.84), mix. Cool, dilute to1litre
25、and mix. Sulphuric acid (5% v/v). To400ml of water, add cautiously50ml of sulphuric acid (sp. gr.1.84), mix, cool, dilute to1litre and mix. Thiourea (5%w/v). Dissolve5g of thiourea in90ml of warm water (about60 C). Cool, dilute to100ml and mix. Filter if necessary. This solution should be prepared i
26、mmediately before use. 4 Sampling Recommended methods of obtaining a suitable sample for the analytical procedure given below are described in BS1499 “Sampling non-ferrous metals”. 5 Procedure 5.1 Proceed as follows. (Note7.1). 5.1.1 For tin contents less than0.008%. Weigh1g of sample and transfer t
27、o a250ml conical beaker. Add20ml of water then10ml of sulphuric acid(50%). When the reaction has subsided allow to cool. 5.1.2 For tin contents0.008 to0.08%. Weigh1g of sample and transfer to a250ml conical beaker. Add20ml of water then10ml of sulphuric acid(50%). When the reaction has subsided, coo
28、l, transfer to a250ml volumetric flask, dilute to the mark and mix. Transfer by means of a pipette25ml of this solution to a250ml conical beaker, then add5ml of sulphuric acid(50%). Tin content Standard deviation % 0.005 0.029 0.081 0.00029 0.0023 0.0034 1) BS3978, “Water for laboratory use”.BS3907-
29、13:1972 2 BSI 12-1999 5.2 Add the following freshly prepared mixture: 5ml of ascorbic acid solution(2%); 20ml of thiourea solution(5%); 20ml of quercetin solution(0.1%). Allow to stand for15minutes then transfer to a separating funnel, washing the beaker with15ml of isobutyl methyl ketone and transf
30、erring this to the separating funnel. Shake for one minute. Allow the layers to separate and discard the aqueous layer. 5.3 Add25ml of sulphuric acid(5%) to the separating funnel and shake for30seconds, allow the layers to separate and discard the aqueous layer. 5.4 Dry the stem of the separating fu
31、nnel with filter paper then transfer the organic layer to a25ml volumetric flask. Wash the separating funnel with5ml of ethanol(95%) and add the washings to the flask. Dilute to the mark with ethanol(95%) and mix. 5.5 Measure the optical density of the solution using the conditions specified under A
32、pparatus using a mixture of equal volumes of ethanol(95%) and isobutyl methyl ketone as the reference solution. 6 Calibration 6.1 Proceed as follows. (Note7.1). 6.1.1 For tin contents less than0.008%. To five250ml conical beakers add the following quantities (Note7.2): 6.1.2 For tin contents0.008 to
33、0.08%. To four250ml volumetric flasks transfer by means of a pipette the following quantities: (Note7.2) Dilute to the mark and mix. Transfer by means of a pipette25ml of each solution to a series of250ml conical beakers and add the following (Note7.2): 6.2 Continue from paragraph5.2 of the Procedur
34、e. 6.3 Measure the optical density using the conditions specified under Apparatus and prepare a calibration graph by plotting the optical density against the equivalent percentage of tin. 7 Notes 7.1 The calibration should be carried out at the same time as the test. 7.2 These quantities have been c
35、hosen so that each solution has a volume of30ml and contains5.0ml of sulphuric acid(50%). Standard tin solution Tin equivalent Sulphuric acid(50%) Water (1mlN 0.01mg of tin) ml 0 2 4 6 8 % 0 0.002 0.004 0.006 0.008 ml 5.0 4.6 4.2 3.8 3.4 ml 25.0 23.4 21.8 20.2 18.6 Standard tin solution Sulphuric ac
36、id(50%) (1ml N 0.05mg of tin) ml 0 5 10 15 ml 5 5 5 5 Tin equivalent Sulphuric acid(50%) Water % 0 0.025 0.050 0.075 ml 4.5 4.4 4.3 4.2 ml 0.5 0.6 0.7 0.8blankBS3907-13: 1972 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for
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