1、BRITISH STANDARD BS 1728-23: 1976 Methods for The analysis of aluminium and aluminium alloys Part 23: Copper (atomic absorption method) UDC 669.71:543.422:546.56BS1728-23:1976 This British Standard, having been prepared under the directionof the Non-ferrous Metals Standards Committee,waspublished un
2、derthe authorityof the ExecutiveBoardon 29October1976 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference NFE/-/3 Draft for comment 75/42794 DC ISBN 0 580 09298 4 Cooperating organizations The Non-ferrous Metals Standards Committee, under whose supervisi
3、on this British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: Aluminium Federation* Association of Bronze and Brass Founders British Electrical and Allied Manufacturers Association British Lead Manufacturers A
4、ssociation British Non-ferrous Metals Federation BNF Metals Technology centre* Copper Development Association Electric Cable Makers Confederation Institute of British Foundrymen Institution of Mechanical Engineers Institution of Mining and Metallurgy Institution of Production Engineers Institution o
5、f Structural Engineers Lead Development Association Light Metal Founders Association* London Metal Exchange Magnesium Industry Council Ministry of Defence* National Brassfoundry Association Non-ferrous Metal Stockists Royal Institute of British Architects Society of Motor Manufacturers and Traders L
6、td. Tin Research Institute Zinc Development Association Individual firm The 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: Association of Light Alloy Refiners Lt
7、d. Department of Industry Laboratory of the Government Chemist Amendments issued since publication Amd. No. Date of issue CommentsBS1728-23:1976 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Introduction 1 2 Apparatus 1 3 Solutions required 1 4 Sampling 1 5 P
8、rocedure 1 6 Calibration 2 7 Calculation 2 8 Notes 2 Publications referred to Inside back coverBS1728-23:1976 ii BSI 12-1999 Foreword This method for the determination of copper is the twenty-third of a series which will form a complete British Standard under the collective title “Methods for the an
9、alysis of aluminium and aluminium alloys”, each being published as a separate Part. Other methods in the series are as follows: Part 1: Copper; Part 2: Magnesium; Part 5: Copper (absorptiometric method); Part 6: Iron (volumetric: titanous chloride method); Part 8: Iron (absorptiometric 1:10-phenanth
10、roline method); Part 9: Manganese (volumetric: arsenite/nitrite method); Part 10: Manganese (absorptiometric method); Part 11: Silicon (perchloric acid method); Part 12: Silicon (absorptiometric molybdenum blue method); Part 13: Titanium (absorptiometric chromotropic acid method); Part 14: Nickel (g
11、ravimetric method); Part 15: Nickel (photometric method); Part 16: Chromium (photometric method); Part 17: Chromium (volumetric method); Part 18: Zinc (ion-exchange-volumetric EDTA or polarographic method); Part 19: Magnesium (atomic absorption method); Part 20: Lead (atomic absorption method); Part
12、 21: Zinc (atomic absorption method); Part 22: Magnesium (volumetric CDTA method); Part 24: Nickel (atomic absorption method). The preparation of this series of methods has been authorized by the Non-ferrous Metals Standards Committee as part of a general programme for the standardization of methods
13、 for the sampling and analysis of non-ferrous metals. The 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. This
14、method is substantially the same as the corresponding method approved by ISO/TC79which will be published as International Standard ISO 3980 1) . A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct app
15、lication. 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 and ii, pages 1 to 4, an inside back cover and a back cover. This standard has been updated (see copyright da
16、te) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In course of preparation.BS1728-23:1976 BSI 12-1999 1 1 Introduction NOTEThe titles of the publications referred to in this standard are listed on inside back cover. 1.1 Principl
17、e. The sample is dissolved in hydrochloric acid and diluted to a suitable volume and the copper content is determined by atomic absorption spectrophotometry. 1.2 Range. The method is recommended for copper contents between0.005% and5.0%. 1.3 Reproducibility. Experiments have been carried out indepen
18、dently by a number of analysts using this method. The degree of reproducibility that can be expected is shown by the following analysis of the results obtained. 2 Apparatus 2.1 Class A volumetric glassware complying with the appropriate British Standards shall be used throughout. The burette used sh
19、ould be graduated in0.05ml subdivisions. 2.2 Any atomic absorption spectrophotometer with adequate sensitivity and precision and preferably attached to a chart recorder readout or integrating device and capable of measuring absorption at a wavelength of324.7nm. A slot burner with air/acetylene flame
20、. A multi-slot burner is advisable when the total solid concentration in the solutions to be aspirated exceeds0.5%. 2.3 Copper hollow cathode lamp 3 Solutions required All reagents shall be of the highest purity obtainable 2)and distilled or demineralized water shall be used throughout. Standard cop
21、per (1 ml N 0.1mg of copper). Dissolve1.0 0.001g of high purity copper(99.95% pure) in5ml of water and5ml of nitric acid (sp. gr. 1.42), warming gently until dissolution is complete and crystallization begins. Take up with water, warming if necessary, to dissolve salts, transfer to a1litre volumetri
22、c flask, dilute to the mark and mix. Transfer100ml of this solution to a1litre volumetric flask, dilute to the mark and mix. Standard copper (1 ml N 0.01mg of copper). Transfer100ml of standard copper solution(1 ml N 0.1mg of copper) to a1litre volumetric flask, dilute to the mark and mix. Aluminium
23、 (2% w/v). Weigh20.0 0.01g ofhigh purity aluminium (note 8.1) and transfer toa1litre beaker. Add in small portions100ml of hydrochloric acid (50%), then add a drop of metallic mercury. Heat gently to start the reaction, then add in small portions a further400ml of hydrochloric acid(50%). When the re
24、action subsides, add gradually250ml of special grade hydrochloric acid (sp. gr.1.16to 1.18) and heat gently if necessary to complete the reaction. Add a few millilitres of hydrogen peroxide (100 vol.) and boil to remove excess hydrogen peroxide. Allow to cool, transfer toa1litre volumetric flask, di
25、lute to the mark and mix. Hydrochloric acid (50% v/v). Dilute500ml of special grade hydrochloric acid (sp. gr.1.16to1.18) to1litre and mix. Nitric acid (50% v/v). Dilute100ml of nitric acid (sp. gr. 142) to200ml and mix. 4 Sampling Recommended methods of obtaining a suitable sample for the analytica
26、l procedure given below are described in BS 1499. 5 Procedure 5.1 Weigh1.0 0.001g of sample, transfer toa250ml beaker (note 8.2) and add30ml to40ml of water, then in small portions30ml of hydrochloric acid (50%) (note 8.3). Cover with a watchglass and warm gently to complete the dissolution. Add a f
27、ew millilitres of hydrogen peroxide (100 vol.) and boil to remove excess hydrogen peroxide. Copper content Standard deviation s % 0.01 0.08 0.7 1.4 5.4 0.0012 0.0025 0.0058 0.025 0.058 2) For certain reagents an extra high quality is now available but this special grade of material is not required u
28、nless specifically stated.BS1728-23:1976 2 BSI 12-1999 5.2 Carry out simultaneously a blank determination following the same procedure and using the same amounts of reagents as with the sample, and replacing the sample by1.0 0.001g of high purity aluminium (note 8.1). 5.3 Filter if necessary through
29、 a close-textured filter paper 3) , wash the precipitate four times with water and add the washings to the sample solution. 5.3.1 For alloys containing up to1% of silicon. Discard the filter paper and residue and retain the solution. 5.3.2 For alloys containing more than1% of silicon. Transfer the f
30、ilter paper and residue to a platinum crucible using forceps, dry and ignite to burn off the paper. Allow to cool, add5ml hydrofluoric acid 4)and five drops of nitric acid (sp. gr. 1.42). When the reaction has subsided, evaporate carefully to dryness (note 8.4), take up the residue in5ml of nitric a
31、cid (50%) and add to the main solution. 5.4 Proceed as follows. 5.4.1 For copper contents0.005% to0.05%. Transfer the solution to a100ml volumetric flask. Dilute to the mark and mix. 5.4.2 For copper contents0.05% to0.5%. Transfer the solution to a1litre volumetric flask, dilute to the mark and mix.
32、 5.4.3 For copper contents0.5% to5%. Transfer the solution to a500ml volumetric flask, dilute to the mark and mix. Transfer100ml of this solution toa500ml volumetric flask, dilute to the mark and mix. 5.5 Aspirate the solution (note 8.2) and record the values of per cent absorption or absorbance dep
33、ending upon the instrument and type of readout. 6 Calibration 6.1 To a series of100ml volumetric flasks transfer the appropriate volume of aluminium solution (2%) indicated in the following table, then add from a burette the respective quantities of standard copper solution (1 ml N0.01mg of copper o
34、r1ml N 0.1mg of copper) as shown in the following table. 6.2 Dilute to the mark and mix. 6.3 Aspirate the solutions (note 8.2) and record the values of per cent absorption or absorbance depending upon the instrument and type of readout. 6.4 Deduct the absorbance reading for the blank and prepare a c
35、alibration graph by plotting absorbance values (see clause 7) against the nominal copper contents of the solutions. 7 Calculation If the instrument reads per cent absorption, convert this to absorbance. Convert the absorbance reading for the test sample corrected for blank to percentage copper by me
36、ans of the calibration graph. 8 Notes 8.1 Millings or drillings of99.99% purity aluminium should be used and these should be cleaned immediately before use with a little nitric acid (sp. gr. 1.42), then washed with water and dried by washing with acetone. 3) Whatman No. 540 is suitable. 4) This refe
37、rs to the usual analytical reagent grade of40% w/w. Copper content Aluminium solution Standard copper solution Corresponding copper in sample 1 ml N 0.01mg of copper % ml ml mg 0.005 to 0.05 50 0, 5, 10, 20 0.00, 0.05, 0.10, 0.20 1 ml N 0.1 mg of copper 3, 4, 5 0.30, 0.40, 0.50 1 ml N 0.01 mg of cop
38、per 0.05 to 0.5 5 0, 5, 10, 20 0.00, 0.05, 0.10, 0.20 1 ml N 0.1 mg of copper 3, 4, 5 0.30, 0.40, 0.50 0.5 to 5.0 2 0, 2, 4, 7, 10, 15, 20, 0.00, 0.20, 0.40, 0.70, 1.00, 1.50, 2.00BS1728-23:1976 BSI 12-1999 3 8.2 The sample solution should be prepared at the same time as the calibration standard sol
39、utions and aspirated immediately after the calibration solutions and blank without altering the instrument settings. After the last sample solution has been aspirated, it is advisable to aspirate the most concentrated standard solution once more. This is to ensure that instrument conditions have not
40、 altered (i.e. atomizer blocked, etc.). 8.3 For samples that are difficult to attack with hydrochloric acid, add a drop of metallic mercury. 8.4 If necessary repeat the treatment with hydrofluoric and nitric acids.4 blankBS1728-23:1976 BSI 12-1999 Publications referred to BS 1499, Sampling non-ferro
41、us metals. ISO 3980, Aluminium alloys Determination of copper 5) . 5) In course of preparation.BS 1728-23: 1976 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 standard
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