BS 7317-1-1990 Methods for analysis of high purity copper cathode Cu-CATH-1 - Method for determination of cadmium manganese and silver (screening procedure for chromium cobalt iron.pdf

1、BRITISH STANDARD BS7317-1: 1990 Methods for Analysis of high purity copper cathode Cu-CATH-1 Part 1: Method for determination of cadmium, manganese and silver (screening procedure for chromium, cobalt, iron, nickel and zinc) by atomic absorption spectrophotometry UDC669.3.015.4:543.422.062:546.48 +

2、546.57 + 546.711BS7317-1:1990 This BritishStandard, having been prepared under the directionof the Non-ferrous Metals Standards Policy Committee, was published underthe authority of the BoardofBSI and comes intoeffecton 31July1990 BSI12-1999 The following BSI references relate to the work on this st

3、andard: Committee referenceNFM/34 Draft for DevelopmentDD95-1 ISBN 0 580 18459 5 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Non-ferrous Metals Standards Policy Committee(NFM/-) to Technical CommitteeNFM/34, upon which the following bo

4、dies were represented: British Bathroom Council British Cable Makers Confederation British Gas plc British Malleable Tube Fittings Association British Non-ferrous Metals Federation British Valve and Actuator Manufacturers Association Copper Development Association London Metal Exchange Non-ferrous M

5、etal Stockists Society of British Aerospace Companies Ltd. Transmission and Distribution Association (BEAMA Ltd.) Coopted members The following bodies were also represented in the drafting of the standard, through subcommittees and panels: BNF Metals Technology Centre British Bronze and Brass Ingot

6、Manufacturers Association Bureau of Analysed Samples Ltd. Copper Smelters and Refiners Association Ministry of Defence Amendments issued since publication Amd. No. Date of issue CommentsBS7317-1:1990 BSI 12-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Princi

7、ple 1 3 Reagents 1 4 Apparatus 2 5 Procedure 2 6 Calculation and expression of results 3 7 Repeatability and reproducibility 4 8 Test report 4 Table 1 Calibration solutions 2 Table 2 Test conditions for impurity element determinations 2 Table 3 Maximum mean differences for impurity elements 3 Table

8、4 Repeatability of results 3 Table 5 Reproducibility of results 4 Publications referred to Inside back coverBS7317-1:1990 ii BSI 12-1999 Foreword BS7317 has been prepared under the direction of the Non-ferrous Metals Standards Policy Committee. It describes methods for the determination of impurity

9、elements in high purity copper cathode designatedCu-CATH-1, each method being published as a separate Part. The methods are based on those previously issued in the Draft for Development series DD95-1 to DD95-7. Theinformation and experience gained from the practical application of DD95have been take

10、n into account in the methods in BS7317. This Part of BS7317 supersedes DD95-1:1984, which is withdrawn. It is one of a series of methods in BS7317, the others being as follows: Part 2: Method for determination of chromium, cobalt, iron, nickel and zinc by discrete volume nebulization atomic absorpt

11、ion spectrophotometry; Part 3: Method for determination of antimony, arsenic, bismuth, selenium, tellurium and tin by hydride generation and atomic absorption spectrophotometry; Part 4: Method for determination of antimony, arsenic, bismuth, lead, selenium, tellurium and tin by electrothermal atomiz

12、ation atomic absorption spectrophotometry; Part 5: Method for determination of sulphur by hydrogen sulphide evolution and spectrophotometry; Part 6: Method for determination of phosphorus and silicon by spectrophotometry; Part 7: Method for determination of lead by lanthanum hydroxide separation and

13、 atomic absorption spectrophotometry. The atomic absorption spectrophotometric procedures in Parts1 and2 are complementary. A sample solution concentration found to be satisfactory for nebulizers in standard atomic absorptiometers was20g/L. At this concentration the precision obtainable, using the m

14、ethod described in Part1, is only sufficient to allow the determination of cadmium, manganese and silver. Results would be obtained for chromium, cobalt, iron, nickel and zinc that would prove useful in detecting impurities grossly in excess of the requirements for chemical compositions specified in

15、 BS6017 for Cu-CATH-1 and would give a guide to the levels to be determined by Part2. The discrete volume nebulization procedure in Part2 was developed to enable a high equivalent sample solution concentration of100g/L to be used without nebulizer blockage. The method involves no chemical separation

16、, which can give rise to contamination problems, and the extra sensitivity obtained enables the impurities to be determined to an adequate accuracy for the requirements for chemical composition specified in BS6017 for Cu-CATH-1. Parts1 and2 essentially cover the same impurities. Part4 covers the ele

17、ctrothermal atomization atomic absorption spectrophotometric method and is recommended where the facility is available. Parts1,2,3 and7 are included for use where the electrothermal atomization equipment is not available. A British Standard does not purport to include all the necessary provisions of

18、 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 to4, an inside back

19、 cover 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.BS7317-1:1990 BSI 12-1999 1 1 Scope This Part of BS7317 describes a method for the determination of the actua

20、l amounts of the impurity elements cadmium, manganese and silver present in high purity copper cathode (designated Cu-CATH-1), by atomic absorption spectrophotometry. The method is also suitable for use as a screening method to determine whether or not the amounts of the impurity elements chromium,

21、cobalt, iron, nickel and zinc present in Cu-CATH-1 exceed the maxima for these elements specified in BS6017. NOTE 1This method is intended to be used for analysis samples prepared by the procedures given in BS6017. These samples should be significantly oxygen free. If this method is used for other m

22、aterials, such as copper wire rod produced from high purity cathodes, where oxygen can be introduced during processing, then low results may be obtained for the chromium and iron contents. NOTE 2The titles of the publications referred to in this Part of BS7317 are listed on the inside back cover. 2

23、Principle The sample of Cu-CATH-1 is dissolved in the minimum of nitric acid and diluted to volume. Theimpurity elements are then determined by direct flame atomic absorption spectrophotometry using matching calibration solutions of reference elements. 3 Reagents 3.1 General 3.1.1 During the analysi

24、s, use only reagents of recognized analytical quality or of higher purity and only distilled water, deionized water, or water of equivalent purity, that has no detectable levels of the particular elements to be determined. 3.1.2 Protect all reagents against contamination with chloride ions, in order

25、 to prevent the precipitation of silver as silver chloride. NOTEUnless otherwise stated, all solutions are aqueous solutions. 3.2 Nitric acid, 1.42g/mL,50% V/V solution. 3.3 Copper 1) , a certified reference material of a minimum of99.999% copper, containing less than0.54g/g of each of the impurity

26、elements. 3.4 Copper solution. Take101g of copper(3.3). Etch the copper with20mL of nitric acid solution(3.2) in a100mL beaker. Wash the etched copper with water, followed by acetone, and dry using gentle heat. Weigh the etched and dried copper to verify that the mass is not less than99.5g. Transfer

27、 the etched copper into a1L volumetric flask and dissolve in600mL of nitric acid solution(3.2) using gentle heat. Cool the solution, dilute to the mark and mix well. Throughout the preparation of the copper solution, exercise extreme care to avoid contamination by tweezers,etc. 3.5 Primary calibrati

28、on solutions, as given in3.5.1 to3.5.8. For these solutions, use one of the following. a) Solutions prepared by the following method. Dissolve1.000g of the pure(99.95% minimum) element in20mL of nitric acid solution(3.2), cool to ambient temperature and transfer to a1L volumetric flask. Dilute to th

29、e mark and mix well. b) Commercially prepared chloride-free solutions (see3.1.2), where available. 3.5.1 Silver nitrate solution containing1.0 0.0005g/L of silver. 3.5.2 Cadmium nitrate solution containing1.0 0.0005g/L of cadmium. 3.5.3 Cobalt nitrate solution containing1.0 0.0005g/L of cobalt. 3.5.

30、4 Chromium nitrate solution containing1.0 0.0005g/L of chromium 2) . 3.5.5 Iron(III) nitrate solution containing1.0 0.0005g/L of iron. 3.5.6 Manganese nitrate solution containing1.0 0.0005g/L of manganese. 3.5.7 Nickel nitrate solution containing 1.0 0.0005g/L of nickel. 3.5.8 Zinc nitrate solution

31、containing1.0 0.0005g/L of zinc. 3.6 Acetone 1) For information on the availability of copper of suitable purity, apply to Enquiry Section, BSI, Linford Wood, Milton Keynes, MK146LE, enclosing a stamped addressed envelope for reply. 2) In order to avoid the difficulty of dissolving metallic chromium

32、, the following procedure for the preparation of the chromium nitrate primary calibration solution is recommended. Weigh2.828g of dried potassium dichromate into a1L beaker. Dissolve in500mL of water and add20mL of nitric acid ( =1.42g/mL). Whilst stirring, add carefully50mL of hydrogen peroxide(30g

33、/LH 2 O 2solution). When the reaction has ceased, bring to the boil and boil gently for15min. Cool and transfer to a1L volumetric flask, dilute to the mark and mix well.BS7317-1:1990 2 BSI 12-1999 4 Apparatus 4.1 Atomic absorption spectrophotometer, incorporating a 10scale expansion facility and fit

34、ted with a burner for use with acetylene/air and hydrogen/air gas mixtures, and a hollow cathode lamp for each element to be determined. NOTEA pure zinc hollow cathode lamp, rather than a copper-zinc hollow cathode lamp, is necessary, because there is a line overlap with the zinc213.856nm line and t

35、he copper213.851nm line, which leads to a high blank reading. 4.2 Laboratory glassware NOTEIt is recommended that new glassware, dedicated to this specific purpose, is used. 5 Procedure 5.1 General Scrupulously clean all glassware in nitric acid solution(3.2) for16h, rinse with distilled water and d

36、ry, immediately before use. 5.2 Preparation of solutions 5.2.1 Stock reference solution. Prepare the stock reference solution by the following method and use within24h to avoid deterioration. Into a1L volumetric flask transfer, using a pipette,10.0mL of the first primary calibration solution(3.5.1)

37、and5.0mL of each of the other primary calibration solutions(3.5.2 to3.5.8). Dilute to the mark with water and mix well. 5.2.2 Calibration solutions. Prepare six calibration solutions (solutions5.2.2.1 to5.2.2.6) by adding, using a pipette, the quantities of the stock reference solution(5.2.1) given

38、in Table 1 to each of six250mL volumetric flasks, adding50mL of copper solution(3.4) to each flask, diluting to the mark and mixing well. 5.2.3 Test portions. Prepare three test portions (solutions5.2.3.1 to5.2.3.3) as follows. Take three5.1g portions of the sample. Etch each portion with20mL of nit

39、ric acid solution(3.2) in a100mL beaker. Wash the etched portions with water, followed by acetone, and dry them using gentle heat. Weigh the etched and dried portions to verify that the mass of each is not less than4.95g. Transfer each of the etched portions into a separate250mL volumetric flask and

40、 dissolve each portion in30mL of nitric acid solution(3.2) using gentle heat. Cool each solution, dilute to the mark and mix well. Throughout the preparation of the test solutions, exercise extreme care to avoid contamination by tweezers,etc. 5.2.4 Reagent blanks. Take three5.1g portions of pure cop

41、per(3.3). Etch the copper with20mL of nitric acid solution(3.2) in a100mL beaker. Wash the etched copper with water, followed by acetone, and dry using gentle heat. Weigh the etched and dried copper to verify that the mass is not less than4.95g. Transfer each of the etched portions of copper into a

42、separate250mL volumetric flask and dissolve each portion in30mL of nitric acid solution(3.2) using gentle heat. Cool each solution, dilute to the mark and mix well. Throughout the preparation of the test solutions, exercise extreme care to avoid contamination by tweezers,etc. Table 1 Calibration sol

43、utions Table 2 Test conditions for impurity element determinations Calibration solution Addition of stock reference solution Equivalent concentration for a5g sample Silver Cadmium, cobalt, chromium iron, manganese, nickel, zinc 5.2.2.1 5.2.2.2 5.2.2.3 5.2.2.4 5.2.2.5 5.2.2.6 mL 0.00 5.00 7.50 10.00

44、15.0 20.00 4g/g 0.00 10.0 15.0 20.0 30.0 40.0 4g/g 0.00 5.0 7.5 10.0 15.0 20.0 Impurity element Wavelength Flame type and condition a Band width Silver Cadmium Manganese Chromium Cobalt Iron Nickel Zinc nm 328.1 228.8 279.5 357.9 240.7 248.3 232.0 213.8 Acetylene/air (ox.) Acetylene/air (ox.) Acetyl

45、ene/air (st.) Acetylene/air (red.) Acetylene/air (ox.) Acetylene/air (ox.) Acetylene/air (red.) Hydrogen/air (st.) b Normal Normal Normal Narrow Narrow Narrow Narrow Normal a The flame conditions are abbreviated as: (ox.): oxidizing, i.e.lean; (st.): stoichiometric and (red.): reducing, i.e.rich. b

46、The use of a hydrogen/air flame reduces interference.BS7317-1:1990 BSI 12-1999 3 5.3 Adjustment of apparatus Adjust the atomic absorption spectrophotometer(4.1), in accordance with the recommendations of the instrument supplier, to give the maximum sensitivity for each element to be determined. Use

47、automatic background correction wherever possible. Choose a scale expansion for each element that gives the best balance between readability and stability over the range of reference solutions. 5.4 Determinations Using the test conditions given in Table 2, measure the absorbance values of each of th

48、e impurity elements three times for each of the calibration solutions(5.2.2.1 to5.2.2.6), six times for each of the test portions(5.2.3.1 to5.2.3.3) and six times for the reagent blanks(5.2.4). Record the absorbance values to0.0001. Table 3 Maximum mean differences for impurity elements Table 4 Repe

49、atability of results 6 Calculation and expression of results 6.1 Calibration calculations For each impurity element, calculate the arithmetic means of the three absorbance value measurements for each of the calibration solutions(5.2.2.1 to5.2.2.6). Construct or calculate a straight line calibration (mean absorbance plotted against calibration solution concentration) for each element using a least squares (first order) fit. From the calibration read off or calculate an apparent impurity element concentration, in4/g(%m/m), correspondi