1、BRITISH STANDARD BS 6783-4: 1986 ISO 7523:1985 Sampling and analysis of nickel, ferronickel and nickel alloys Part 4: Method for determination of silver, arsenic, bismuth, cadmium, lead, antimony, selenium, tin, tellurium and thallium in nickel by electrothermal atomic absorption spectrometry ISO ti
2、tle: Nickel Determination of silver, arsenic, bismuth, cadmium, lead, antimony, selenium, tin, tellurium and thallium contents Electrothermal atomic absorption spectrometric method UDC 669.24 + 669.1524 198:543.422.062BS6783-4:1986 This British Standard, having been prepared under the directionof th
3、e Non-ferrous Metals Standards Committee, waspublished under the authorityof the Board of BSI andcomes into effect on 31 December 1986 BSI 10-1999 ISBN 0 580 15523 4 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Non-ferrous Metals Stan
4、dards Committee (NFM/-) to Technical Committee NFM/10, upon which the following bodies were represented: British Non-ferrous Metals Federation British Steel Industry Engineering Equipment and Materials Users Association Ministry of Defence Process Plant Association Stainless Steel Fabricators Associ
5、ation of Great Britain Coopted members Amendments issued since publication Amd. No. Date of issue CommentsBS6783-4:1986 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 1 2 References 1 3 Principle 1 4 Reagents 1 5 Apparatus
6、2 6 Sampling and samples 2 7 Procedure 3 8 Expression of results 4 9 Interferences and precautions 4 10 Sample inhomogeneity 5 11 Test report 5 Annex A Alternative method for preparation and purification of nickel nitrate solution for electrothermal atomic absorption analysis 6 Annex B Statistical r
7、eport of interlaboratory tests 6 Table 1 Concentration ranges of elements to be determined 1 Table 2 Set of calibration solutions A 3 Table 3 Set of calibration solutions B 3 Table 4 Spectral lines 3 Table 5 Results of statistical analysis 8 Publications referred to Inside back coverBS6783-4:1986 ii
8、 BSI 10-1999 National foreword This Part of BS 6783 has been prepared under the direction of the Non-ferrous Metals Standards Committee. It is identical with ISO 7523:1985 “Nickel Determination of silver, arsenic, bismuth, cadmium, lead, antimony, selenium, tin, tellurium and thallium contents Elect
9、rothermal atomic absorption spectrometric method” published by the International Organization for Standardization (ISO). At present this British Standard consists of nine Parts all concerned with analysis of nickel, ferronickel and nickel alloys. Further International Standards are in preparation on
10、 sampling and analysis of nickel, ferronickel and nickel alloys and, when available, these will be published as further Parts of this British Standard. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without devi
11、ation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker.
12、Wherever the words “International Standard” appear, referring to this standard, they should be read as “Part of BS 6783”. In British Standards it is current practice to use the symbol “L” for litre (and in its submultiples) rather than “l”. The Technical Committee has reviewed the provisions of ISO
13、385-1, ISO 648 and ISO 6283, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. ISO 385-1 is related to BS 846:1985 “Specification for burettes” and ISO 648 is related to BS 1583:1986 “Specification for one-mark pipettes”. A Br
14、itish Standard does not purport to include all the necessary 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. Cross-references International Standards Corr
15、esponding British Standards ISO 1042:1983 BS 1792:1982 Specification for one-mark volumetric flasks (Identical) ISO 3534:1977 BS 5532 Statistical terminology Part 1:1978 Glossary of terms relating to probability and general terms relating to statistics (Identical) ISO 5725-1981 BS 5497 Precision of
16、test methods Part 1:1979 Guide for the determination of repeatability and reproducibility for a standard test method (Technically equivalent) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 8, an inside back cover and a back cover. This standa
17、rd 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.BS6783-4:1986 BSI 10-1999 1 1 Scope and field of application This International Standard specifies an electrothermal atomic absorption spectromet
18、ric method for the determination of the silver, arsenic, bismuth, cadmium, lead, antimony, selenium, tin, tellurium and thallium contents of high purity, refined, wrought and cast nickel within the ranges specified in Table 1. This method is applicable to the independent determination of any one or
19、more of the elements listed without including all elements specified in the standard solutions. Table 1 Concentration ranges of elements to be determined For potential interferences and precautions, seeclause 9. 2 References ISO 385-1, Laboratory glassware Burettes Part1: General requirements. ISO 6
20、48, Laboratory glassware One-mark pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks. ISO 5725, Precision of test methods Determination of repeatability and reproducibility by inter-laboratory tests. 3 Principle Dissolution of a test portion in nitric acid and dilution of the solutio
21、n to a known volume. Introduction of a known volume of the solution into an electrothermal atomizer of an atomic absorption spectrometer. Measurement of the absorption of the resonance line energy from the spectrum of each element and comparison with that of calibration solutions of the same element
22、 in a matched nickel matrix using background correction. 4 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only deionized water or water of equivalent purity. 4.1 Nitric acid, 20= 1,41 g/ml. The same batch of nitric acid shall be used throu
23、ghout the procedure. NOTEIt may be necessary to redistil the nitric acid if high blanks are obtained. 4.2 Nitric acid, 20= 1,41 g/ml, diluted 1 + 19. The same batch of nitric acid shall be used throughout the procedure. 4.3 Mixed analyte standard solutions 4.3.1 Analyte stock standard solutions, cor
24、responding to 1,000 g of Ag, As, Bi, Cd, Pb, Sb, Se, Sn, Te and Tl per litre. Prepare separately for each metal of interest. 4.3.1.1 Silver, arsenic, bismuth, cadmium, lead, selenium and tellurium. Weigh, to the nearest 0,000 1 g, 0,100 g of the high purity 99,9 % (m/m), minimum elements, transfer t
25、o a 100 ml beaker and dissolve in 10 ml of nitric acid diluted 1 + 1. Heat to complete dissolution, boil gently to expel oxides of nitrogen, cool and transfer to a one-mark 100 ml volumetric flask containing10ml of nitric acid diluted 1 + 1. Make up to the mark with water and mix. Store in a glass b
26、ottle. 4.3.1.2 Antimony Weigh exactly 0,274 g of potassium antimonyl tartrate hemihydrate K(SbO)C 4 H 4 O 6 1/2H 2 O, transfer to a 100 ml one-mark volumetric flask, dissolve in water and dilute to the mark. Prepare this solution freshly as mould forms in old solutions. The more dilute acidified sol
27、utions are stable. 4.3.1.3 Thallium Weigh exactly 0,112 g of thallium(III) oxide (Tl 2 O 3 ), transfer to a 100 ml beaker and dissolve in 10 ml hot nitric acid (4.1). Transfer to 100 ml one-mark volumetric flask, make up to the mark with water and mix. Store in a glass bottle. Element Concentration
28、range a(4g/g) b Ag As Bi Cd Pb Sb Se Sn Te Tl 0,1 to 10 1 to 20 0,5 to 15 0,1 to 2 0,1 to 10 1 to 10 1 to 10 1 to 5 0,2 to 10 0,5 to 10 a For specific compositions, see ISO 6283. b 1 4g/g = 1 g/tBS6783-4:1986 2 BSI 10-1999 4.3.1.4 Tin Weigh, to the nearest 0,001 g, 0,250 g of high purity99,9 % (m/m)
29、, minimum tin metal, transfer to a100 ml plastic beaker and dissolve in 7,5 ml of a mixture of equal parts by volume of 48 % (m/m) hydrofluoric acid ( 20= 1,13 g/ml), nitric acid(4.1) and water. Heat to complete dissolution, boil gently to expel oxides of nitrogen, cool and transfer to a250ml plasti
30、c one-mark volumetric flask. Make up to the mark with water and mix. Store in a plastic bottle. 4.3.2 Mixed analyte standard solution A, corresponding to 1,0 mg of As, Bi, Pb, Sb, Se, Sn, Te and Tl per litre. 4.3.2.1 Pipette 10,0 ml of each of the 1,000 g/l stock standard solutions (4.3.1.1) of As,
31、Bi, Pb, Sb, Se, Sn, Te and Tl into a 1 000 ml one-mark volumetric flask containing 100 ml of nitric acid diluted 1 + 1. Make up to the mark with water and mix. Store in a glass bottle (5.6). 4.3.2.2 Pipette 10,0 ml of this solution (4.3.2.1) into a 100 ml one-mark volumetric flask containing10ml of
32、nitric acid diluted 1 + 1. Make up to the mark with water and mix. Store in a glass bottle (5.6). 4.3.3 Mixed analyte standard solution B, corresponding to 0,1 mg of Ag and Cd per litre. 4.3.3.1 Pipette 10,0 ml of each of the 1,000 g/l stock standard solutions (4.3.1.1) of silver and cadmium into a
33、1 000 ml one-mark volumetric flask containing 100 ml of nitric acid diluted 1 + 1. Make up to the mark with water and mix. Store in a glass bottle (5.6). 4.3.3.2 Pipette 10,0 ml of this solution (4.3.3.1) into a 1 000 ml one-mark volumetric flask containing100 ml of nitric acid diluted 1 + 1. Make u
34、p to the mark with water and mix. This solution is not stable and should be prepared immediately before use. 4.4 Nickel nitrate, stock solution, containing 40 g of Ni per litre. 4.4.1 Weigh, to the nearest 0,001 g, 4,00 g of high purity (containing less than 5 g of Fe per tonne and less than 1 g of
35、silver, arsenic, bismuth, cadmium, lead, antimony, selenium, tin, tellurium and thallium per tonne) nickel metal and transfer to a400 ml beaker. Add 50 ml of water and 28 ml of nitric acid (4.1). Allow to stand and do not stir until most of the metal is dissolved as the reaction is vigorous. Heat to
36、 complete dissolution, boil gently to expel oxides of nitrogen and cool. 4.4.2 Filter through a dense filter paper which has been prewashed with nitric acid diluted 1 + 1. Return the filtrate through the filter paper again to collect fine carbon particles which tend to be present in the first filtra
37、te. Collect the second filtrate in a100 ml one-mark volumetric flask, wash the filter with water. Make up to the mark with water and mix. The solution contains approximately 0,8 mol of free HNO 3per litre 5 % (V/V). NOTEFor details concerning an alternative method for the preparation and purificatio
38、n of the solution, see Annex A. 5 Apparatus Ordinary laboratory apparatus, and 5.1 Atomic absorption spectrometer and electrothermal atomizer 5.1.1 The instrument shall be equipped with a background corrector and a high-speed recorder or computerized read out. 5.1.2 The instrument should be capable
39、of using single element hollow cathode or electrodeless discharge lamps operated at currents recommended by the lamp and instrument manufacturer. 5.2 Burettes, of capacities 5 ml and 10 ml, graduated in divisions of 0,01 ml, in accordance with ISO 385-1, class A. 5.3 Pipettes, of capacities 10 and 2
40、5 ml, in accordance with ISO 648, class A. 5.4 Volumetric flasks, of capacities 10; 100; 200; 250; and 1 000 ml, in accordance with ISO 1042, class A. 5.5 Micropipettes, of capacities 5 to 25 4l. 5.6 Glass storage bottles The glass bottles used to store mixed analyte standard solutions shall be thor
41、oughly cleaned, soaked several days in nitric acid (4.2), and rinsed thoroughly with water. 6 Sampling and samples 6.1 Sampling and preparation of the laboratory sample shall be carried out by normal agreed procedures or, in case of dispute, by the relevant International Standard. 6.2 The laboratory
42、 sample normally is in the form of a powder, granules, millings or drillings and no further preparation of the sample is necessary. 6.3 If it is suspected that the laboratory sample is contaminated with oil or grease from the milling or drilling process, it shall be cleaned by washing with high puri
43、ty acetone and drying in air. 6.4 If the laboratory sample contains particles or pieces of widely varying sizes, the test portion should be obtained by riffling.BS6783-4:1986 BSI 10-1999 3 7 Procedure 7.1 Preparation of test solution Weigh, to the nearest 0,01 g, 0,9 to 1,1 g of the laboratory sampl
44、e and transfer to a clean unetched100 ml beaker. Add 30 ml of water and12ml of nitric acid (4.1) and allow to dissolve. Heat to complete dissolution, boil gently to expel oxides of nitrogen, cool and transfer to a 100 ml one-mark volumetric flask. Make up to the mark with water and mix. NOTEThe life
45、 of the graphite furnace tubes can be extended by using 5 ml of nitric acid rather than 12 ml. 7.2 Blank test The zero members of the sets of calibration solutions(7.3) serve as blank tests since the same batch of nitric acid is used for dissolution of both the nickel reference and test portions. If
46、 it is impossible to use the same batch of nitric acid, a second blank test shall be prepared using the same high purity nickel metal. This blank is then compared to the zero member and an appropriate correction made, if significant. 7.3 Preparation of calibration solutions 7.3.1 Set A 7.3.1.1 This
47、set corresponds to 0; 0,005; 0,010; 0,02; 0,05; 0,07; 0,1; 0,15; 0,20; 0,25 and 0,30 mg of each of As, Bi, Pb, Sb, Se, Sn, Te and Tl per litre (seeTable 2) and is used for analyte levels from 0,5 to 30,0 g/t. All solutions contain a matrix of 10 g of Ni per litre. Table 2 Set of calibration solution
48、s A 7.3.1.2 Transfer 2,50 ml of nickel nitrate stock solution (4.4) from a burette to each of 11, 10 ml one-mark volumetric flasks. Add, using a burette,0;0,05; 0,1; 0,2; 0,5; .0,7; 1,0; 1,5; 2,0; 2,5; and 3,0 ml respectively of mixed analyte standard solution A (4.3.2). Make up to the mark with nit
49、ric acid diluted 1 + 19 (4.2) and mix. 7.3.2 Set B 7.3.2.1 This set corresponds to 0; 0,0005; 0,001; 0,002; 0,005; 0,010; 0,02 and 0,05 mg of each of Ag and Cd per litre (see Table 3) and is used for analyte levels from 0,01 to 5,0 g/t. All solutions contain a matrix of 10 g of Ni per litre. Table 3 Set of calibration solutions B 7.3.2.2 Transfer 2,50 ml of nickel nitrate stock solution (4.4) from a burette to each of eight 10 ml one-mark volumetric flasks. Add, using a burette,0;0,05; 0,1; 0,2; 0,5; 1,0; 2,0 and 5,0 ml res
