BS 6200-3 12 3-1986 Sampling and analysis of iron steel and other ferrous metals - Methods of analysis - Determination of copper - Steel and cast iron flame atomic absorption spect.pdf

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1、BRITISH STANDARD BS 6200-3.12.3: 1986 EN 24943:1990 ISO 4943:1985 Incorporating Amendment No. 1 Sampling and analysis of iron, steel and other ferrous metals Part 3: Methods of analysis Section 3.12 Determination of copper Subsection 3.12.3 Steel and cast iron: flame atomic absorption spectrometric

2、method The European Standard EN 24943:1990 has the status of a British Standard. UDC 669.1:543.422:546.56BS6200-3.12.3:1986 This British Standard, having been prepared under the directionof the Iron and Steel Standards Committee, was published under the authority of the Board of BSI and comes into e

3、ffect on 30 September 1986 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference ISM/18 Draft for comment 84/42467 DC ISBN 0 580 15338 X Amendments issued since publication Amd. No. Date of issue Comments 7071 February 1992 Indicated by a sideline in the m

4、arginBS6200-3.12.3:1986 BSI 10-1999 i Contents Page National foreword ii Brief history 2 1 Scope and field of application 3 2 Reference 3 3 Principle 3 4 Reagents 3 5 Apparatus 3 6 Sampling 4 7 Procedure 4 8 Expression of results 6 9 Test report 6 Annex A Additional information on the international

5、co-operative tests 7 Annex B Graphical representation of precision data 8 Figure Relationship between copper content and repeatability r or reproducibility R 8 Table 1 5 Table 2 6 Table 3 7 Publication referred to Inside back cover BS6200-3.12.3:1986 ii BSI 10-1999 National foreword This Subsection

6、of BS 6200 has been prepared under the direction of the Iron and Steel Standards Committee. It is identical with ISO4943 “Steel and cast iron Determination of copper content Flame atomic absorption spectrometric method” published by the International Organization for Standardization (ISO). In 1990 t

7、he European Committee for standardization (CEN) accepted ISO4943:1985 as European Standard EN 24943:1990. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain convention

8、s 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. Wherever the words “International Standard” ap

9、pear, referring to this standard, they should be read as “British Standard”. Cross-reference. The Technical Committee has reviewed the provisions of ISO/R377, to which reference is made in clause6, and has decided that they are acceptable for use in conjunction with this standard. A related standard

10、 to ISO/R377 is BS1837 “Methods for the sampling of iron, steel, permanent magnet alloys and ferro-alloys”. Appropriate procedures from ISO/R377 will be incorporated in BS6200-2 “Methods of sampling and sample preparation”, which will be published in due course and which will supersede BS1837. A Bri

11、tish 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. Summary of pages This document comprises a fro

12、nt cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 8, an inside back 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.EUROPEAN STAND

13、ARD NORME EUROPENNE EUROPISCHE NORM EN 24943 March 1990 UDC 669.1:543.422:546.56 Descriptors: Steels, cast iron chemical analysis, determination of content, copper, atomic absorption spectrophotometry, flame photometry English version Steel and cast iron Determination of copper content Flame atomic

14、absorption spectrometric method (ISO 4943:1985) Aciers et fontes Dosage du cuivre Mthode par spectromtrie dabsorption atomique dans la flamme (ISO 4943:1985) Stahl and Gueisen Bestimmung des Kupfergehalts Flammenatom- absorptionsspektrometrisches Verfahren (ISO 4943:1985) This European Standard was

15、approved by CEN on 1989-11-27. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national

16、 standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notifi

17、ed to the Central Secretariat has the same status as the official versions. CEN members are the national standards organizations of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKi

18、ngdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN 1990 Copyright reserved to all CEN members Ref. No. EN 24943:1990 EEN24943:1990 2 BSI 10-1999 Brief history On the proposal of

19、the Technical Committee ECISS/TC20 “Methods of chemical analysis” the Coordinating Commission (COCOR) of the European Committee for Iron and Steel Standardization (ECISS) decided in November1986 to submit the International Standard to the Formal Vote. This European Standard was adopted by CEN on1989

20、-11-27. According to the Common CEN/CENELEC Rules, being part of the Internal Regulations of CEN, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Sp

21、ain, Sweden, Switzerland and UnitedKingdom. Statement The text of the International Standard ISO4943, edition 1, 1985 was approved by CEN as a European Standard without any modification. ISO 4943:1985 Steel and cast iron Determination of copper content Flame atomic absorption spectrometric methodEN2

22、4943:1990 BSI 10-1999 3 1 Scope and field of application This International Standard specifies a method for the determination of copper in steel and cast iron by means of flame atomic absorption spectrometry. The method is applicable to copper contents in the range0,004 to0,5% (m/m). 2 Reference ISO

23、/R 377, Selection and preparation of samples and test pieces for wrought steel. 3 Principle Dissolution of a test portion in a mixture of hydrochloric, nitric and perchloric acids. Spraying of the solution into an air-acetylene flame. Spectrometric measurement of the atomic absorption of the 324,7 n

24、m spectral line emitted by a copper hollow cathode lamp. 4 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and having a very low copper content, and only distilled water or water of equivalent purity. If possible, use only freshly prepared dist

25、illed or de-ionized water. 4.1 Iron of high purity, copper content 99,95% (m/m) Cu. Transfer to a 400 ml beaker and dissolve in25ml of nitric acid ( about 1,40g/ml, diluted1 + 4). Cover with a watch-glass. When dissolution is complete, evaporate on a water-bath until the onset of crystallization. Di

26、ssolve the residue in water, cool, transfer to a1000ml one-mark volumetric flask, dilute to the mark and mix. 4.4.2 Standard solution, corresponding to20mg of Cu per litre. Transfer 20,0ml of the stock solution (4.4.1) into a1000ml one-mark volumetric flask, dilute to the mark and mix. 1 ml of this

27、standard solution contains204g of Cu. Prepare this standard solution immediately before use. 5 Apparatus Ordinary laboratory apparatus, and 5.1 Atomic absorption spectrometer A copper hollow cathode lamp; supplies of air and acetylene sufficiently pure to give a steady clear fuel-lean flame, free fr

28、om water and oil, and free from copper. The atomic absorption spectrometer used will be satisfactory if after optimization according to7.3.4 the limit of detection and characteristic concentration are in reasonable agreement with the values given by the manufacturer and it meets the precision criter

29、ia given in5.1.1. 5.1.1 Minimum precision Calculate the standard deviation of10 measurements of the absorbance of the most concentrated calibration solution. The standard deviation shall not exceed1,0% of the mean absorbance. Calculate the standard deviation of 10 measurements of the absorbance of t

30、he least concentrated calibration solution (excluding the zero member). The standard deviation shall not exceed 0,5% of the mean absorbance of the most concentrated calibration solution. It is also desirable that the instrument should conform to the additional performance requirements given in5.1.1.

31、1 to5.1.1.3. 5.1.1.1 Characteristic concentration The characteristic concentration for copper in a matrix similar to the final test portion solution shall be better than0,104g of Cu per millilitre.EN24943:1990 4 BSI 10-1999 5.1.1.2 Limit of detection This is defined as twice the standard deviation o

32、f 10 measurements of the absorbance of a solution containing the appropriate element of a concentration level selected to give an absorbance just above that of the zero member. The limit of detection of copper in a matrix similar to the final test portion solution shall be better than0,154g of Cu pe

33、r millilitre. 5.1.1.3 Graph linearity The slope of the calibration graph covering the top20% of the concentration range (expressed as a change in absorbance) shall not be less than0,7 times the value of the slope for the bottom20% of the concentration range (expressed as a change in absorbance) dete

34、rmined in the same way. For instruments with automatic calibration using two or more standards, it shall be established prior to the analysis, by obtaining absorbance readings, that the above requirements for graph linearity are fulfilled. 5.2 Ancillary equipment A strip chart recorder and/or digita

35、l readout device is recommended to evaluate the criteria in5.1.1 and for all subsequent measurements. Scale expansion can be used until the noise observed is greater than the read-out error and is always recommended for absorbances below0,1. If scale expansion has to be used and the instrument does

36、not have the means to read the value of the scale expansion factor, the value can be calculated by measuring a suitable solution with and without scale expansion and simply dividing the signal obtained. 6 Sampling Carry out sampling in accordance with ISO/R377 or appropriate national standards for c

37、ast iron. 7 Procedure WARNING Perchloric acid vapour may cause explosions in the presence of ammonia, nitrous fumes or organic matter in general. Ensure that the spray system and drainage system are washed free from perchloric acid after use. NOTEAll glassware shall first be washed in hydrochloric a

38、cid ( about 1,19g/ml, diluted1 + 1), then in water. The quantity of copper present in the beakers and flasks can be checked by measuring the absorption of the distilled water introduced into the glassware after the acid wash. 7.1 Test portion Weigh, to the nearest 0,001g, approximately 0,5g of the t

39、est sample. 7.2 Blank test Parallel with the determination and following the same procedure, carry out a blank test using the same quantities of all the reagents. 7.3 Determination 7.3.1 Preparation of the test solution Place the test portion (7.1) in a250ml beaker. Add, in small portions, 20ml of t

40、he hydrochloric acid-nitric acid-perchloric acid mixture(4.3), cover the beaker with a watch-glass and heat gently until solvent action ceases. Evaporate until dense white fumes of perchloric acid appear. Continue fuming for1min at such a temperature as to maintain a steady reflux of white perchlori

41、c acid fumes on the walls of the beaker. NOTEFor samples not readily soluble in the hydrochloric acid-nitric acid-perchloric acid mixture(4.3), first dissolve in10ml of the hydrochloric acid-nitric acid mixture(4.2) before adding the20ml of the hydrochloric acid-nitric acid-perchloric acid mixture(4

42、.3). Allow to cool, add 25ml of water and heat gently to dissolve salts. Cool again and transfer quantitatively to a100ml one-mark volumetric flask. Dilute to the mark and mix. Filter by decantation through a dry medium filter paper to remove any residue or precipitate, for example graphite, silica

43、or tungstic acid, and collect the filtrate in a dry beaker after discarding the first runnings. If the expected copper content of the test sample exceeds0,1% (m/m), the solution shall be diluted as follows. Transfer 20,0 ml of the solution to a 100ml one-mark volumetric flask, dilute to the mark and

44、 mix. NOTEIf the solution has to be diluted to give the test solution, the blank test(7.2) must be diluted in the same way. 7.3.2 Preparation of the calibration solutions Place 10 0,01 g of the iron(4.1) in a1litre beaker. Add in small portions400ml of the hydrochloric acid-nitric acid-perchloric ac

45、id mixture(4.3) and heat gently until dissolved. When dissolution is complete, evaporate until dense white fumes of perchloric acid appear. Continue fuming for 1 min at such a temperature as to maintain a steady reflux of white perchloric acid fumes on the walls of the beaker. Allow to cool, add 100

46、ml of water and heat gently to dissolve salts. Cool again and transfer the solution quantitatively to a500ml one-mark volumetric flask. Dilute to the mark and mix.EN24943:1990 BSI 10-1999 5 7.3.2.1 Copper content 0,1% (m/m) Transfer a series of25,0 ml aliquots of the iron solution (7.3.2) to100ml on

47、e-mark volumetric flasks. Add to the flasks from a pipette or burette respectively0 (the zero member);2,5; 5,0; 10,0; 15,0; 20,0; and25,0ml of the copper standard solution (4.4.2). Dilute to the mark and mix. 7.3.2.2 Copper content 0,1 to 0,5% (m/m) Transfer a series of 5,0 ml aliquots of the iron s

48、olution (7.3.2) to100ml one-mark volumetric flasks. Add to the flasks from a pipette or burette respectively0 (the zero member); 2,5; 5,0; 10,0; 15,0; 20,0; and 25,0ml of the copper standard solution(4.4.2). Dilute to the mark and mix. NOTE1 ml of the copper standard solution (4.4.2), diluted to100m

49、l is equivalent to0,004% (m/m) Cu in the case of7.3.2.1 and 0,02% (m/m) Cu in the case of7.3.2.2. 7.3.3 Adjustment of atomic absorption spectrometer See Table 1. Table 1 In the absence of the bandwidth recommendations mentioned inTable 1 the following guideline is suggested: copper 324,7 nm bandwidth within the range0,3 to 1,0nm NOTEThe manufacturers recommendations should be closely followed and particular attention is drawn to the following safety points: a) the explosive nature of acetylene, and regulations concerning its use;