1、BRITISH STANDARD BS EN 12441-9:2004 Zinc and zinc alloys Chemical analysis Part 9: Determination of nickel in zinc alloys Flame atomic absorption spectrometric method The European Standard EN 12441-9:2004 has the status of a British Standard ICS 77.040.30; 77.120.60 BS EN 12441-9:2004 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 45286 7 National foreword This British Standard is the official English language version of EN 12441-9:2004. 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 11 and a back cover. The BSI copyright notice displayed in this document i
7、ndicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN124419 December2004 ICS77.040.30;77.120.60 Englishversion ZincandzincalloysChemicalanalysisPart9:Determination ofnickelinzincalloysFlameatomicabsorpt
8、ionspectrometric method ZincetalliagesdezincAnalysechimiquePartie9: DosagedunickeldanslesalliagesdezincMthodepar spectromtriedabsorptionatomiquedanslaflamme ZinkundZinklegierungenChemischeAnalyseTeil9: BestimmungvonNickelinZinklegierungenFAAS Verfahren ThisEuropeanStandardwasapprovedbyCENon4November
9、2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariato
10、rtoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodie
11、sofAustria,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 COMITEUROPENDENO
12、RMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN124419:2004:EEN 12441-9:2004 (E) 2 Contents Page Foreword3 1 Scope4 2 Normative references4 3 Terms and defini
13、tions .4 4 Principle4 5 Reagents.4 6 Apparatus.5 7 Sampling.6 8 Procedure.6 9 Calculation and expression of results.7 10 Test report8 Annex A (informative) Additional information on international co-operative tests .9 Annex B (informative) Graphical representation of precision data .10 Bibliography
14、11 EN 12441-9:2004 (E) 3 Foreword This document (EN 12441-9:2004) 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 text
15、 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/WG6 “Methods of analysis and testing“ to prepare the following document: EN 12441-9, Zin
16、c and zinc alloys Chemical analysis Part 9: Determination of nickel in zinc alloys 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: Determinatio
17、n 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 Spectrophotom
18、etric 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 8: Determination of tin in secondary zinc Flame atomic absorption spectrometric method Part 10: Determ
19、ination 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 European
20、 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 12441-9:2004 (
21、E) 4 1 Scope This document specifies a flame atomic absorption spectrometric method for the determination of nickel in zinc alloys. It is applicable to the products specified in EN 1774 and EN 12844. It is suitable for the determination of nickel contents (mass fractions) between 0,000 5 % and 0,020
22、 %. 2 Normative references 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 1774, Zinc and zinc
23、 alloys Alloys for foundry purposes Ingot and liquid EN 12060:1997, Zinc and zinc alloys Method of sampling Specifications EN 12844, Zinc and zinc alloys Castings Specifications 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12060:1997 and the follow
24、ing term and definition apply. 3.1 atomic absorption spectrometry measurement of the absorption of an electromagnetic 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 rad
25、iation of specific wavelengths and the intensity of the absorbed radiation is proportional to the concentration of said element 4 Principle A sample of the alloy is dissolved in a nitric acid and, after adequate dissolution and atomisation of the solution in an air-acetylene flame, the content of ni
26、ckel is determined by atomic absorption spectrometry at the wavelength of 232,0 nm. 5 Reagents 5.1 General During the test, use only reagents of known or analytical grade and distilled or demineralised water. 5.2 Nitric acid, = 1,4 g/ml EN 12441-9:2004 (E) 5 5.3 Nickel, 1,0 g/l standard solution Int
27、roduce 0,500 g of nickel with a purity of no less than 99,99 % (mass fraction) in the form of stripes, wire or powder, weighted to the nearest 0,001 g, into a 250 ml beaker fitted with a watch-glass. Add a few millilitres of water, 20 ml of nitric acid (5.2) and dissolve while gently heating. Dilute
28、 the solution with about 50 ml of water and boil to expel the nitrogen oxides. Cool to room temperature and transfer quantitatively to a 500 ml volumetric flask. Dilute to the mark with water and mix. 1 ml of this standard solution contains 1 mg of nickel. 5.4 Nickel, standard solution A Transfer 25
29、 ml of nickel solution (5.3) into a 1 000 ml volumetric flask and add 5 ml of nitric acid (5.2). Dilute to the mark with water and mix. 1 ml of this standard solution contains 0,025 mg of nickel. 5.5 Nickel, standard solution B Transfer 25 ml of nickel solution (5.3) into a 250 ml volumetric flask a
30、nd add 1 ml of nitric acid (5.2). Dilute to the mark with water and mix. 1 ml of this standard solution contains 0,100 mg of nickel. 5.6 Pure zinc, (nickel content below 0,2 g/g) 5.7 Aluminium nitrate nonahydrate, (nickel content below 1 g/g) Test the nickel content before use, as this reagent may c
31、ontain considerable amounts of nickel. 1,390 g corresponds to 0,100 g of aluminium. 5.8 Hydrochloric acid, = 1,19 g/ml 5.9 Aqua regia Mix 3 part volumes of hydrochloric acid (5.8) with 1 part volume nitric acid (5.2). 6 Apparatus 6.1 General All glassware used for the preparation of the solutions an
32、d for the implementation of the method shall be cleaned with boiling aqua regia (5.9) prior to use. 6.2 Specific equipment In addition to standard laboratory apparatus, an atomic absorption spectrometer, equipped with a premix burner, with facilities for using the oxidiser-fuel combination of air-ac
33、etylene, 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 cm. EN 12441-9:2004 (E) 6 7 Sampling The test sample shall be selected and prepared in accordance with the pr
34、ocedure given in EN 12060. 8 Procedure 8.1 Test portion Weigh 10 g of the test sample to the nearest 0,01 g. 8.2 Preparation of the test solution 8.2.1 Introduce the test portion (8.1) into a 400 ml beaker fitted with a watch-glass. Add 20 ml of water and dissolve by carefully adding 50 ml of nitric
35、 acid (5.2). Boil the solution to expel the nitrogen oxides. 8.2.2 Cool to room temperature and transfer quantitatively to a 100 ml volumetric flask. Dilute to the mark with water and mix. 8.3 Preparation of the calibration solutions 8.3.1 To each of a series of seven 400 ml beakers, add a g of the
36、pure zinc (5.6), 20 ml of water, then carefully c ml of nitric acid (5.2) and, gently heat until complete dissolution. Allow to cool, add b g of aluminium nitrate nonahydrate (5.7) and, after dissolution, transfer quantitatively to a series of 100 ml volumetric flasks. For a, b and c, see Table 1. T
37、able 1 Preparation of the calibration solutions Aluminium content (mass fraction) a b c smaller than 0,05 % 10 0 50 between 3,7 % and 6,0 % 9,5 7 46 between 8,0 % and 11,0 % 9 14 42 between 25,0 % and 28 % 7,5 35 30 8.3.2 After cooling to room temperature, add 0,00 ml, 2,00 ml, 4,00 ml and 8,00 ml a
38、liquots of the nickel standard solution A (5.4) and 5,0 ml, 10,0 ml and 20,0 ml aliquots of the nickel standard solution B (5.5). These aliquots correspond to nickel contents (mass fractions) in the test portion of 0,000 0 %, 0,000 5 %, 0,001 0 %, 0,002 0 %, 0,005 0 %, 0,010 % and 0,020 %. Dilute to
39、 the mark with water and mix. 8.4 Spectrometric measurements Measure the absorbances of the calibration solutions and the test solution(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 sh
40、all be 232,0 nm. To comply with the concentration ranges recommended by the manufacturer of the apparatus, the same dilutions for the calibration solutions and the test solution(s) shall be made if necessary. EN 12441-9:2004 (E) 7 9 Calculation and expression of results 9.1 Method of calculation Est
41、ablish a calibration graph by plotting the measured absorbances of the calibration solutions against their respective contents (mass fractions). Determine from the measured absorbances of the test solutions the associated amount of nickel from the calibration graph. If a number of determinations are
42、 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 results shall be expressed as specified in EN 1774 and EN 12844. 9.2 Precision A planned trial of this method was carried out by 10 laborator
43、ies, using 4 samples with 4 levels of nickel contents, each laboratory making three determinations of nickel content in each sample (see Notes 1 and 2) NOTE 1 Two of the three determinations were carried out under repeatability conditions as defined in ISO 5725-1; i.e. one operator, same apparatus,
44、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 operator as in Note 1, using the same apparatus and a different calibration. The details of the samples used and the mean
45、 results obtained are given in the Tables A.1 and A.2. The results obtained were treated statistically in accordance with ISO 5725. The data obtained showed a logarithmic relationship between the nickel content and the repeatability limit (r) and reproducibility limits (R wand R) of the test results
46、 (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 repeatability limit (r) and the reproducibility limit (R) were calculated using the procedure specified in ISO 5725. From the first value obtain
47、ed 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 2 Repeatability limit and reproducibility limits Nickel content Repeatability limit Reproducibility limits % (mass fraction) r R w R 0,000 5
48、0,000 04 0,000 15 0,000 18 0,001 0 0,000 06 0,000 18 0,000 28 0,002 0 0,000 10 0,000 22 0,000 44 0,005 0 0,000 19 0,000 30 0,000 78 0,010 0 0,000 31 0,000 37 0,001 19 0,020 0 0,000 50 0,000 46 0,001 84 EN 12441-9:2004 (E) 8 10 Test report The test report shall include the following details: a) identification of the sample; b) test method used, (i.e. reference to this document); c) nickel content, expressed as a percentage by mass, giving where possible the results for the
