1、BRITISH STANDARD BS ISO 11438-6:1993 Implementation of ISO11438-6:1993 Ferronickel Determination of trace-element content by electrothermal atomic absorption spectrometric method Part6: Determination of thallium content UDC 669.245:543.422.064:546.683BSISO11438-6:1993 This BritishStandard, having be
2、en prepared under the directionof the Non-ferrous Metals Standards Policy Committee, was published underthe authority of the Standards Board and comesintoeffect on 15May1994 BSI01-2000 The following BSI references relate to the work on this standard: Committee reference NFM/10 Draft for comment92/42
3、091 DC ISBN 0 580 23356 1 Committees responsible for this British Standard The preparation of this BritishStandard was entrusted by the Non-ferrous Metals Standards Policy Committee (NFM/-) to Technical Committee NFM/10, upon which the following bodies were represented: Association of Bronze and Bra
4、ss Founders British Non-ferrous Metals Federation British Stainless Steel Association British Steel Industry Department of Trade and Industry (Laboratory of the Government Chemist) Engineering Equipment and Materials Users Association Institute of British Foundrymen London Metal Exchange Ministry of
5、 Defence Nickel Development Institute Non-ferrous Metal Stockists Steel Casting Research and Trade Association Coopted members Amendments issued since publication Amd. No. Date CommentsBSISO11438-6:1993 BSI 01-2000 i Contents Page Committees responsible Inside front cover National foreword ii Forewo
6、rd iii Text of ISO11438-6 1BSISO11438-6:1993 ii BSI 01-2000 National foreword This BritishStandard reproduces verbatim ISO11438-6:1993 and implements it as the UK national standard. This BritishStandard is published under the direction of the Non-ferrous Metals Standards Policy Committee whose Techn
7、ical Committee NFM/10 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate t
8、hem in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, Publications, BSI, Linford Wood, Milton Keynes, MK146LE. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards
9、 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, theISO title page, pagesii toiv, pages1 and2 and a back cover. Th
10、is 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.ISO11438-6:1993(E) ii BSI 01-2000 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 Principle 1 4 Reagents 1 5 Apparatus 1
11、 6 Sampling and sample preparation 1 7 Procedure 1 7.1 Preparation of test solution 1 7.2 Blank test 1 7.3 Determination by the standard additions method 1 7.3.1 Atomic absorption measurements 1 7.3.2 Semi-quantitative estimation of the thallium content 1 7.3.3 Quantitative determination of the thal
12、lium content 1 7.3.4 Plotting of standard additions 1 7.4 Number of determinations 1 8 Expression of results 2 8.1 Calculation 2 8.1.1 Semi-quantitative estimation of the thallium content 2 8.1.2 Quantitative determination of the thallium content 2 8.1.3 Calculation of the thallium content 2 8.2 Pre
13、cision 2 8.2.1 Laboratory tests 2 8.2.2 Statistical analysis 2 9 Test report 2 Table 1 Nominal composition of test samples 2 Table 2 Results of statistical analysis 2ISO11438-6:1993(E) BSI 01-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of nati
14、onal standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Internat
15、ional organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical commit
16、tees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO11438-6 was prepared by Technical Committee ISO/TC155, Nickel and nickel alloys, Sub-Committee SC3, Analysis o
17、f nickel and ferronickel. ISO11438 consists of the following parts, under the general title Ferronickel Determination of trace-element content by electrothermal atomic absorption spectrometric method: Part1: General requirements and sample dissolution; Part2: Determination of lead content; Part3: De
18、termination of antimony content; Part4: Determination of tin content; Part5: Determination of tellurium content; Part6: Determination of thallium content; Part7: Determination of silver content; Part8: Determination of indium content.iv blankISO11438-6:1993(E) BSI 01-2000 1 1 Scope This part of ISO1
19、1438 specifies an electrothermal atomic absorption spectrometric method for the determination of thallium in the range of0,3g/t to1,0g/t in ferronickel, according to the principle of standard additions. The general requirements concerning the apparatus, sampling, dissolution of the test sample, proc
20、edure, calculation and test report are given in ISO11438-1. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO11438. At the time of publication, the editions indicated were valid. All standards are subjec
21、t to revision, and parties to agreements based on this part of ISO11438 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO5725:1986, Precision o
22、f test methods Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests. ISO11438-1:1993, Ferronickel Determination of trace-element content by electrothermal atomic absorption spectrometric method Part1: General requirements and sample dissolution. 3 P
23、rinciple Dissolution of a test portion in nitric acid. Measurement of the absorption of the resonance line energy from the spectrum of thallium in the test solution at a wavelength of276,8nm by an atomic absorption spectrometer fitted with a graphite furnace electrothermal atomizer. Calibration by t
24、he standard additions method described in ISO11438-1. 4 Reagents In addition to the reagents listed in ISO11438-1, the following special reagents are required. 4.1 Thallium, standard reference solution(1000mg/l). Weigh, to the nearest0,0005g,0,1117g of high purity thallium(III) oxide (Tl 2 O 3 ). Tr
25、ansfer to a100ml beaker and dissolve in10ml of hot nitric acid ( 20 =1,41g/ml). Cool the solution and transfer to a100ml one-mark volumetric flask. Make up to the mark with water and mix thoroughly. 4.2 Thallium, standard solution(10,0mg/l). Pipette10,0ml of the thallium standard reference solution(
26、4.1) into a1000ml one-mark volumetric flask containing50ml of nitric acid ( 20 =1,41g/ml) diluted1+1. Make up to the mark with water and mix thoroughly. This solution shall be prepared on the day of use. 4.3 Thallium, working standard solution(1,0mg/l). Pipette10,0ml of the thallium standard solutio
27、n(4.2) into a100ml one-mark volumetric flask containing5ml of nitric acid( 20 =1,41g/ml) diluted1+1. Make up to the mark with water and mix thoroughly. This solution shall be freshly prepared. 5 Apparatus The apparatus required is specified in clause5 of ISO11438-1:1993. 6 Sampling and sample prepar
28、ation Refer to clause6 of ISO11438-1:1993. 7 Procedure 7.1 Preparation of test solution Proceed as directed in7.1 of ISO11438-1:1993. 7.2 Blank test Refer to7.2 of ISO11438-1:1993. 7.3 Determination by the standard additions method 7.3.1 Atomic absorption measurements Use the peak area integration a
29、bsorbance measurement at a wavelength of276,8nm and proceed with checking the electrothermal atomizer as directed in7.3.1 of ISO11438-1:1993. 7.3.2 Semi-quantitative estimation of the thallium content Proceed as directed in7.3.2 of ISO11438-1:1993. 7.3.3 Quantitative determination of the thallium co
30、ntent Proceed as directed in7.3.3 of ISO11438-1:1993. 7.3.4 Plotting of standard additions Proceed as directed in7.3.4 of ISO11438-1:1993. NOTE 1The procedure is applicable to the linear part of the graphs. 7.4 Number of determinations Carry out the determination at least in duplicate.ISO11438-6:199
31、3(E) 2 BSI 01-2000 8 Expression of results 8.1 Calculation 8.1.1 Semi-quantitative estimation of the thallium content Proceed as directed in8.1.1 of ISO11438-1:1993. 8.1.2 Quantitative determination of the thallium content Proceed as directed in8.1.2 of ISO11438-1:1993. 8.1.3 Calculation of the thal
32、lium content Calculate the thallium content w Tlof the test sample, in grams per tonne, using the formula 8.2 Precision 8.2.1 Laboratory tests Five laboratories in three countries participated in the testing of this procedure using two samples of nominal composition given in Table 1. Samples were an
33、alysed three times on different days. 8.2.2 Statistical analysis 8.2.2.1 Results from the interlaboratory test programme were evaluated according to ISO5725 as described in8.2.2 of ISO11438-1:1993. The results of this analysis are given in Table 2. 8.2.2.2 One laboratory was rejected as a Dixon outl
34、ier for sample1. 9 Test report Refer to clause10 of ISO11438-1:1993. Table 1 Nominal composition of test samples Table 2 Results of statistical analysis where Tl is the thallium concentration, in micrograms per litre, found in the “zero” test solution, in accordance with8.1.2 of ISO11438-1:1993; m i
35、s the mass, in grams, of the test portion; F is the dilution factor of2,5. w Tl F Tl 10m - = Sample Content, g/t Content, % (m/m) Pb Sb Sn Te Tl Ag In Bi As Se Cd Ga Ge Zn Ni Fe 1 1 1 1 0,5 0,5 1 0,5 0,1 3 0,5 0,5 2 1 2 25 Remainder 2 6 4 10 2 1 6 2 1 5 3 1 4 4 5 25 Remainder Sample 1 2 Mean W Tl ,
36、g/t 0,33 0,82 Within-laboratory standard deviation 0,05 0,1 Between-laboratory standard deviation 0,1 Repeatability 0,1 0,3 Reproducibility 0,1 0,4blankBS ISO 11438-6:1993 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for pre
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