1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12938:2000 Incorpor
2、ating Corrigendum No. 1 The European Standard EN 12938:1999 has the status of a British Standard ICS 77.120.60 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Methods for the analysis of pewter Determination of alloying and impurity element contents by atomic spectrometryThis
3、British Standard, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 February 2000 BSI 08-2001 ISBN 0 580 35463 6 BS EN 12938:2000 Amendments issued since publication Amd. No. Date Com
4、ments 12045 Corrigendum No. 1 August 2001 Insertion of new version of 4.13.3 National foreword This British Standard is the official English language version of EN 12938:1999, including corrigendum August 2000. The UK participation in its preparation was entrusted to Technical Committee NFE/27, Tin
5、and tin alloys, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgat
6、e them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the sectio
7、n entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. C
8、ompliance 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, the EN title page, pages 2 to 15 and a back cover. The BSI copyright notice displayed in this document indicates when the docume
9、nt was last issued.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12938 November 1999 ICS 77.120.60 Incorporating corrigendum August 2000 English version Methods for the analysis of pewter - Determination of alloying and impurity element contents by atomic spectrometry Mthodes danalyse de ltai
10、n pour la fabrication dobjets - Dtermination de la teneur en alliages et en impurets par spectromtrie atomique Analyse von Zinnlegierungen - Bestimmung des Gehaltes an Legierungs- und Verunreinigungselementen durch Atomspektrometrie This European Standard was approved by CEN on 8 October 1999. CEN m
11、embers 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 standards may be obtained on applic
12、ation 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 notified to the Central Secretariat has th
13、e same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE
14、FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Central Secretariat: rue de Stassart, 36 B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12938:1999 EPage 2 EN 12938:1999 BSI 02
15、-2000 Contents Foreword 3 1 Scope 4 2 Normative references 4 3 Principle 4 4 Reagents 4 5A p p a r a t u s 5 6 Sampling 6 7 Procedure 6 8 Expression of results 7 9 Test report 8 Annex A (normative) Method for checking atomic absorption spectrometer performance (based on ISO 7530-1:1990) 9 Annex B (n
16、ormative) Method for checking atomic emission spectrometer performance 12 Bibliography 15Page 3 EN 12938:1999 BSI 02-2000 Foreword This European Standard has been prepared by Technical Committee CEN/TC 220, Tin and tin alloys, the Secretariat of which is held by BSI. This European Standard shall be
17、given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2000, and conflicting national standards shall be withdrawn at the latest by May 2000. According to the CEN/CENELEC Internal Regulations, the national standards organizations o
18、f the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Within its programme of work, T
19、echnical Committee CEN/TC 220 requested CEN/TC 220/WG1, “Methods of analysis for tin and tin alloys”, to prepare the following standard: EN 12938 Methods for the analysis of pewter Determination of alloying and impurity element contents by atomic spectrometry. The annexes A and B are normative.Page
20、4 EN 12938:1999 BSI 02-2000 1 Scope This European Standard specifies atomic spectroscopic methods (either AAS or AES) for the analysis of pewter alloy defined in EN 611-1. NOTE This method is also suitable for inductively-coupled plasma emission spectrometry (ICP). It is written for use by experienc
21、ed analysts familiar with atomic spectrometric techniques. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafte
22、r. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 611-1 Tin and tin alloys Pewter and
23、pewterware Part 1: Pewter 3 Principle The test sample is dissolved in hydrochloric acid plus nitric acid and tartaric or citric acid, and the concentration of the element sought is measured using atomic absorption spectrometry (AAS) or atomic emission spectrometry (AES). Interference is minimised by
24、 matching sample and standard materials and by the choice of instrument parameters. For alloying amounts of silver dissolution of the sample in dilute nitric acid, followed by measurement as above. 4 Reagents 4.1 General During the analysis, unless otherwise stated, use only reagents of recognised a
25、nalytical grade and only distilled water or water of equivalent purity. 4.2 Hydrochloric acid, concentrated ( 1,18 g/ml). 4.3 Dilute hydrochloric acid (1 + 1). Dilute 100 ml hydrochloric acid (4.2) with 100 ml water. NOTE For safety reasons, the acid should be added to the water. 4.4 Dilute hydrochl
26、oric acid (1 + 19). Dilute 10 ml hydrochloric acid (4.2) with 190 ml water. NOTE For safety reasons, the acid should be added to the water. 4.5 Nitric acid, ( 1,42 g/ml). 4.6 Sulphuric acid, ( 1,84 g/ml). 4.7 Tartaric acid or citric acid. 4.8 Acid mixture. Add 250 ml hydrochloric acid (4.2) to 250 m
27、l water. Cool. Add 250 ml nitric acid (4.5) and 50 g tartaric (or citric) acid (4.7). Dilute to 1 l with water.Page 5 EN 12938:1999 BSI 02-2000 4.9 Dilute nitric acid (1 + 1). Add 100 ml nitric acid (4.5) to 100 ml water. 4.10 Dilute nitric acid (1 + 4). Add 50 ml nitric acid (4.5) to 200 ml water.
28、4.11 Dilute nitric acid (1 + 9). Add 25 ml nitric acid (4.5) to 225 ml water. 4.12 Dilute nitric acid (1%). Dilute 5 ml nitric acid (4.5) up to 500 ml. 4.13 Standard solutions of metals. Freshly purchased standard metal solutions may be used or standard metal solutions should be made up as follows (
29、4.13.1 to 4.13.7). 4.13.1 Standard antimony solution (1 ml contains 1 mg Sb). Place 0,10 g Sb in 5 ml sulphuric acid (4.6) and heat to complete dissolution. Cool. Carefully add approximately 10 ml water and cool again. Transfer to a 100 ml volumetric flask with dilute hydrochloric acid (1 + 1) (4.3)
30、. 4.13.2 Standard copper solution (1 ml contains 1 mg Cu). Dissolve 0,10 g Cu in 10 ml dilute nitric acid (1 + 4) (4.10) and transfer to a 100 ml volumetric flask. Make up to volume with water. Mix well. 4.13.3 Standard copper solution (1 ml contains 10 mg Cu). Dissolve 1 g Cu in 30 ml nitric acid (
31、1 + 4) (4.10) and transfer to a 100 ml volumetric flask. Make up to volume with water. Mix well. 4.13.4 Standard lead solution (1 ml contains 1 mg Pb). Dissolve 0,10 g Pb in 10 ml dilute nitric acid (1 + 4) (4.10) and transfer to a 100 ml volumetric flask. Make up to volume with water. Mix well. 4.1
32、3.5 Standard bismuth solution (1 ml contains 1 mg Bi). Dissolve 0,10 g Bi in 10 ml dilute nitric acid (1 + 1) (4.9) and transfer to a 100 ml volumetric flask. Make up to volume with water. Mix well. 4.13.6 Standard cadmium solution (1 ml contains 1 mg Cd). Dissolve 0,10 g Cd in 10 ml dilute nitric a
33、cid (1 + 4) (4.10) and transfer to 100 ml volumetric flask. Make up to volume with water. Mix well. 4.13.7 Standard silver solution (1 ml contains 1 mg Ag). Dissolve 0,787 g silver nitrate in 50 ml water. Transfer to a 500 ml volumetric flask and make up to the volume with nitric acid (1 %) (4.12).
34、Mix well. 4.13.8 Standard silver solution (1 ml contains 0,1 mg Ag). Transfer 10 ml silver solution (4.13.7) to a 100 ml volumetric flask. Make up to volume with water. Mix well. 4.14 Tin, min. purity 99,99 % (mass fraction). 5 Apparatus 5.1 Ordinary laboratory apparatus. Use grade A glassware. 5.2
35、Burette, of capacity 5 ml, graduated in 0,02 ml. 5.3 Atomic absorption or atomic emission spectrometer, conforming to the performance requirements in normative annexes A and B. NOTE Plasma inductively-coupled emission spectrometer is also suitable. 5.4 Hollow cathode lamps or electrodeless discharge
36、 lamps for antimony, bismuth, cadmium, copper, lead and silver. NOTE The presence of other elements may also need to be ascertained.Page 6 EN 12938:1999 BSI 02-2000 5.5 Analytical balance, with an accuracy of 0,1 mg. 6 Sampling The sample for analysis shall be obtained as described in EN 611-1. 7 Pr
37、ocedure 7.1 Preparation of the solution of the sample under test for the determination of antimony, copper, lead, bismuth, cadmium and silver up to 0,01 %. 7.1.1 Weigh accurately about 0,5 g of the sample and transfer to a 150 ml beaker. Add 20 ml of the acid mixture (4.8), heat to complete dissolut
38、ion and cool. Transfer to a 100 ml volumetric flask and make up to the mark with dilute hydrochloric acid (1 + 19) (4.4). Mix well. 7.1.2 For the determination of antimony in all alloys and for copper in alloys nos. 1, 2, 3 and 6 (see EN 611-1), introduce 10 ml of the solution (7.1.1) into a 100 ml
39、volumetric flask and make up to the mark with dilute hydrochloric acid (1 + 19) (4.4). Mix well. 7.1.3 Prepare a blank solution following the procedure described in 7.1.1, but using 0,5 g of high purity tin (4.14) instead of the sample. 7.2 Preparation of the sample for the determination of silver f
40、rom 0,01 % to 5 % (mass fraction). Weigh accurately 0,5 g 0,1 g of the sample into a 250 ml beaker. Add 20 ml dilute nitric acid (1 + 1) (4.9), warm to dissolve, add antibumping granules or similar and boil vigorously to expel brown fumes. Cool and transfer the solution and the precipitate to a 250
41、ml volumetric flask with dilute nitric acid (1 + 9) (4.11). Mix well and allow to stand until the precipitate has settled. For the determination of silver by ICP and for up to 0,2 % by AAS use this solution. For high silver content determinations by AAS, transfer 10 ml of this solution to a 100 ml g
42、raduated flask and dilute to the mark with dilute nitric acid (1 + 9) (4.11). NOTE 1 Tin and antimony will be precipitated out of the solution containing nitric acid and will not therefore be in the solution being analysed for silver content. NOTE 2 All glassware and reagents should be chlorine free
43、. Before use, it is recommended that all glassware is thoroughly rinsed with distilled water. To prepare a range of standard solutions, transfer 15 ml, 20 ml, 30 ml, 40 ml, 50 ml and 60 ml silver solution (4.13.7) into 250 ml volumetric flasks. Add sufficient standard copper solution (1 ml contains
44、10 mg Cu) (4.13.3) to matrix match the copper content of the alloys being analysed. Finally dilute to the mark with dilute nitric acid (1 + 1) (4.9). Mix well. 7.3 Preparation of calibration solutions For the determination of antimony, copper, lead, bismuth and cadmium, weigh 0,5 g 0,1 g tin (4.14)
45、into a 400 ml beaker. Add 50 ml of the acid mixture (4.8) and heat to complete dissolution. Cool and transfer to a 100 ml volumetric flask and make up to the mark with dilute hydrochloric acid (1 + 19) (4.4). Mix well. To each of seven 100 ml volumetric flasks, first add 10 ml of this solution and t
46、hen add the amounts of the standard metal solutions shown in Table 1.Page 7 EN 12938:1999 BSI 02-2000 Table 1 Volume of standard metal solutions used in the preparation of the calibration solutions Flask No. Standard metal solution Ml Sb Cu (4.13.2) Pb Bi Cd Ag 1 2 20 0,20 0,20 0,20 0,05 0,2 3 25 0,
47、50 0,50 0,50 0,10 0,5 4 30 1,0 0,75 1,0 0,20 1,0 5 35 5,0 1,0 1,5 0,25 2,0 6 40 10,0 1,5 2,0 0,30 4,0 7 45 15,0 2,0 2,5 0,40 8,0 8 10,0 Finally, dilute all the solutions to the mark with dilute hydrochloric acid (4.4). For the determination of antimony in all samples and for copper in alloy numbers
48、1, 2, 3 and 6 transfer 10,0 ml of the solutions to a 100 ml flask and dilute to the mark with dilute hydrochloric acid (4.4). 7.4 Certified reference materials (CRM) Where CRM of similar matrix to the sample under test is available, treat an appropriate sample of the CRM in exactly the same way as t
49、he sample under test (7.1). 7.5 Spectrometric measurements Set up the spectrometer (AAS or AES) using the wavelengths given in A.3.5 or B.3.3, as appropriate. A minimum of two runs of the sample under analysis shall be made; first the calibration solutions, then the samples under analysis, and the cycle repeated without altering the instrument parameters. For the purposes of calculating the element content in the sample, the average of readings from a minimum of two separate runs shall be used. NOTE This also applies to
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