1、BRITISH STANDARD BS EN 12441-8:2004 Zinc and zinc alloys Chemical analysis Part 8: Determination of tin in secondary zinc Flame atomic absorption spectrometric method The European Standard EN 12441-8:2004 has the status of a British Standard ICS 77.040.30; 77.120.60 BS EN 12441-8:2004 This British S
2、tandard was published under the authority of the Standards Policy and Strategy Committee on 14 January 2005 BSI 14 January 2005 ISBN 0 580 45285 9 National foreword This British Standard is the official English language version of EN 12441-8:2004. The UK participation in its preparation was entruste
3、d to Technical Committee NFE/8, Zinc, which has the responsibility to: 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
4、found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are r
5、esponsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and ke
6、ep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 10, an inside back cover and a back cover. The BSI copyright notice displa
7、yed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN124418 December2004 ICS77.040.30;77.120.60 Englishversion ZincandzincalloysChemicalanalysisPart8:Determination oftininsecondary
8、zincFlameatomicabsorptionspectrometric method ZincetalliagesdezincAnalysechimiquePartie8: DosagedeltaindanslezincMthodeparspectromtrie dabsorptionatomiquedanslaflamme ZinkundZinklegierungenChemischeAnalyseTeil8: BestimmungvonZinninSekundrzinkFAASVerfahren ThisEuropeanStandardwasapprovedbyCENon4Novem
9、ber2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretari
10、atortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbo
11、diesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPEND
12、ENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN124418:2004:EEN 12441-8:2004 (E) 2 Contents Page Foreword3 1 Scope4 2 Normative references4 3 Terms and def
13、initions .4 4 Principle4 5 Reagents.4 6 Apparatus.5 7 Sampling.5 8 Procedure.5 9 Calculation and expression of results.6 10 Test report7 Annex A (informative) Additional information on international co-operative tests .8 Annex B (informative) Graphical representation of precision data .9 Bibliograph
14、y 10 EN 12441-8:2004 (E) 3 Foreword This document (EN 12441-8:2004) has been prepared by Technical Committee CEN/TC 209 “Zinc and zinc alloys”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical te
15、xt or by endorsement, at the latest by June 2005, and conflicting national standards shall be withdrawn at the latest by June 2005. Within its programme of work, Technical Committee CEN/TC 209 entrusted CEN/TC 209/WG 6 “Methods of analysis and testing“ to prepare the following document: EN 12441-8,
16、Zinc and zinc alloys Chemical analysis Part 8: Determination of tin in secondary zinc Flame atomic absorption spectrometric method This document is a part of a series of eleven standards. The other documents are: Part 1: Determination of aluminium in zinc alloys Titrimetric method Part 2: Determinat
17、ion of magnesium in zinc alloys Flame atomic absorption spectrometric method Part 3: Determination of lead, cadmium and copper Flame atomic absorption spectrometric method Part 4: Determination of iron in zinc alloys Spectrophotometric method Part 5: Determination of iron in primary zinc Spectrophot
18、ometric method Part 6: Determination of aluminium and iron Flame atomic absorption spectrometric method Part 7: Determination of tin Flame atomic absorption spectrometric method after extraction Part 9: Determination of nickel in zinc alloys Flame atomic absorption spectrometric method Part 10: Dete
19、rmination of chromium and titanium in zinc alloys Spectrophotometric method Part 11: Determination of silicon in zinc alloys Spectrophotometric method According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this Europe
20、an Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 12441-8:2004
21、 (E) 4 1 Scope This document specifies a flame atomic absorption spectrometric method for the determination of tin in secondary zinc. It is applicable to the products specified in EN 13283. It is suitable for the determination of tin contents (mass fractions) between 0,1 % and 1,0 %. 2 Normative ref
22、erences The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12060:1997, Zinc and zinc alloys Metho
23、d of sampling Specifications EN 13283, Zinc and zinc alloys Secondary zinc 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12060:1997 and the following apply. 3.1 flame atomic absorption spectrometry measurement of the absorption of an electromagnetic
24、 radiation, emitted by an element at a determined wavelength, by an absorbent medium (flame) formed by atoms of the same element that are in the ground state. Each element absorbs radiation of specific wavelengths and the intensity of the absorbed radiation is proportional to the concentration of sa
25、id element 4 Principle A sample of the metal is dissolved in a mixture of hydrochloric acid and hydrogen peroxide and, after adequate dilution and atomisation of the solution in a nitrous oxide-acetylene flame, the content of tin is determined by atomic absorption spectrometry at the wavelength of 2
26、35,5 nm. 5 Reagents 5.1 General During the test, use only reagents of known or analytical grade and distilled or demineralised water. 5.2 Hydrochloric acid, = 1,19 g/ml. 5.3 Nitric acid, = 1,4 g/ml. EN 12441-8:2004 (E) 5 5.4 Hydrogen peroxide, 30 % (mass fraction) Hydrogen peroxide solutions are lia
27、ble to be stabilised with products containing tin. Therefore exactly the same volume of hydrogen peroxide shall be used both when dissolving samples and when preparing the calibration solutions. 5.5 Pure zinc 99,995 %, tin free 5.6 Zinc, 100 g/l solution Dissolve 100 g of zinc (5.5) with 600 ml of h
28、ydrochloric acid (5.2). After dissolution, transfer quantitatively to a 1 000 ml volumetric flask. Dilute to the mark with water and mix. 5.7 Tin, 0,5 g/l standard solution Weigh 0,5 g of tin with a purity of no less than 99,9 % (mass fraction) to the nearest 0,001 g. Carefully add 200 ml of hydroch
29、loric acid (5.2). When dissolution is complete, cool to room temperature and transfer quantitatively to a 1 000 ml volumetric flask. Dilute to the mark with water and mix. 1 ml of this solution contains 0,500 mg of tin. 5.8 Aqua regia Mix 3 part volumes of hydrochloric acid (5.2) with 1 part volume
30、nitric acid (5.3). 6 Apparatus 6.1 General All glassware used for the preparation of the solutions and for the implementation of the method shall be cleaned with boiling aqua regia (5.8) prior to use. 6.2 Specific equipment In addition to standard laboratory apparatus an atomic absorption spectromet
31、er, equipped with a premix burner, with facilities for using the oxidizer-fuel combination of nitrous oxide-acetylene, shall be used. NOTE Excitation sources should be operated in accordance with the manufacturers recommendations. The optical path length within the flame should be between 5 cm to 10
32、 cm. 7 Sampling The test sample shall be selected and prepared in accordance with the procedure given in EN 12060. 8 Procedure 8.1 Test portion Weigh 5 g of the test sample to the nearest 0,001 g. EN 12441-8:2004 (E) 6 8.2 Preparation of the test portion 8.2.1 Introduce the test portion (8.1) into a
33、 250 ml beaker fitted with a watch-glass and dissolve by carefully adding 40 ml of hydrochloric acid (5.2). Oxidize and complete the dissolution by adding 100 l of hydrogen peroxide (5.4). Do not heat in order to avoid the loss of SnCl 4 . 8.2.2 After dissolution, cool to room temperature and transf
34、er quantitatively to a 100 ml volumetric flask. Dilute to the mark with water and mix. 8.2.3 Transfer exactly 10,00 ml of this solution, (8.2.2) to a 100 ml volumetric flask, add 10 ml of hydrochloric acid (5.2), dilute to the mark with water and mix. 8.3 Preparation of the calibration solutions To
35、each of a series of eight 100 ml volumetric flasks, transfer 10 ml of the hydrochloric acid (5.2) and 100 l of hydrogen peroxide (5.4). Add 5 ml of the zinc solution (5.6) to each flask. Then add 0,00 ml, 1,00 ml, 2,00 ml, 3,00 ml, 5,00 ml, 7,00 ml, 8,00 ml and 10,0 ml aliquots of the tin standard s
36、olution (5.7). These aliquots correspond to tin contents (mass fractions) in the test portion of 0,0 %, 0,1 %, 0,2 %, 0,3 %, 0,5 %, 0,7 %, 0,8 % and 1,0 %. Dilute to the mark with water and mix. 8.4 Spectrometric measurements Measure the absorbances of the calibration solutions and the test solution
37、(s) by taking alternate readings to ensure that the settings of the burner and of the apparatus do not change during the readings. The wavelength of the line used shall be 235,5 nm. To comply with the concentration ranges recommended by the manufacturer of the apparatus, the same dilutions for the c
38、alibration solutions and the test solution(s) shall be made if necessary. 9 Calculation and expression of results 9.1 Method of calculation Establish a calibration graph by plotting the measured absorbances of the calibration solutions against their respective contents (mass fractions). Determine fr
39、om the measured absorbances of the test solutions, the associated amount of tin from the calibration graph. If a number of determinations are carried out then a mean of all results shall be determined by adding the individual results together and by dividing by the number of individual results. The
40、results shall be expressed as specified in EN 13283. 9.2 Precision A planned trail of this method was carried out by 9 laboratories, using 2 samples with 2 levels of tin contents, each laboratory making three determination of tin content in each sample (see Notes 1 and 2). NOTE 1 Two of the three de
41、terminations were carried out under repeatability conditions as defined in ISO 5725-1; i.e. one operator, same apparatus, identical operating conditions, same calibration and a minimum period of time. NOTE 2 The third determination was carried out at a different time (on a different day) by the same
42、 operator as in Note 1, using the same apparatus and a different calibration. The details of the samples used and the mean results obtained are given in the Tables A.1 and A.2. EN 12441-8:2004 (E) 7 The results obtained were treated statistically in accordance with ISO 5725. The data obtained showed
43、 a logarithmic relationship between the tin content and the repeatability limit (r) and reproducibility limits (R wand R) of the test results (see Note 3), as summarised in Table 1. The graphical representation of the data is shown in Figure B.1. NOTE 3 From the two values obtained in Day 1, the rep
44、eatability limit (r) and the reproducibility limit (R) were calculated using the procedure specified in ISO 5725. From the first value obtained in Day 1 and the value obtained in Day 2, the within-laboratory reproducibility limit (R w ) was calculated using the procedure specified in ISO 5725. Table
45、 1 Repeatability limit and reproducibility limits Tin content Repeatability limit Reproducibility limits % (mass fraction) r R w R 0,2 0,008 9 0,007 0 0,027 1 0,5 0,016 1 0,012 5 0,035 1 1,0 0,025 1 0,019 1 0,042 7 10 Test report The test report shall include the following details: a) identification
46、 of the sample; b) test method used (i.e. reference to this document); c) tin content, expressed as a percentage by mass, giving where possible the results for the individual and mean values; d) any unusual occurrence during the determination; e) any steps in the procedure beyond those specified in
47、this document, and any circumstances that may have affected the results; f) date of the test report; g) name of the laboratory or testing organisation; h) signature of the laboratory manager or other responsible person. EN 12441-8:2004 (E) 8 Annex A (informative) Additional information on internatio
48、nal co-operative tests Table A.1 was derived from the results of European analytical trials carried out in 1999 on 2 test samples in 5 countries involving 9 laboratories. The results of the trials were reported in the document CEN/TC209/WG6 N72 and are shown in Table A.1. The test samples used are listed in Table A.2. Table A.1 Detailed results obtained in the interlaboratory test Precision data Tin content % (mass fraction) Repeatability Reproducibility Sample Referee Found
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