1、BSI Standards PublicationPD CEN/TR 10362:2014Chemical analysis of ferrousmaterials Determinationof selenium in steels Electrothermal atomicabsorption spectrometricmethodPD CEN/TR 10362:2014 PUBLISHED DOCUMENTNational forewordThis Published Document is the UK implementation of CEN/TR10362:2014.The UK
2、 participation in its preparation was entrusted to TechnicalCommittee ISE/102, Methods of Chemical Analysis for Iron and Steel.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of
3、a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 84816 2ICS 77.040.30; 77.080.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was publis
4、hed under the authority of theStandards Policy and Strategy Committee on 30 November 2014.Amendments issued since publicationDate Text affectedPD CEN/TR 10362:2014TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 10362 November 2014 ICS 77.040.30; 77.080.20 English Version Chemical analy
5、sis of ferrous materials - Determination of selenium in steels - Electrothermal atomic absorption spectrometric method Analyse chimique des produits ferreux - Dtermination du slnium dans les aciers - Mthode par spectromtrie dabsorption atomique lectrothermique Chemische Analyse von Eisenwerkstoffen
6、- Bestimmung von Selen in Stahl - Spektrometrisches Verfahren mit elektrothermischer Atomabsorption This Technical Report was approved by CEN on 10 May 2014. It has been drawn up by the Technical Committee ECISS/TC 102. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cro
7、atia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
8、United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No.
9、 CEN/TR 10362:2014 EPD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 2 Contents Page Foreword 3 1 Scope 4 2 Normative references 4 3 Principle 4 4 Reagents .4 5 Apparatus .5 6 Sampling .5 7 Procedure .6 8 Measurements 7 9 Expression of results 7 10 Precision .8 11 Test report 8 Annex A (informative) Typica
10、l operating parameters 9 Annex B (informative) Instruments and the instrumental conditions used by the participants to the precision test 11 Annex C (informative) Composition of the samples used for the precision test . 12 Annex D (informative) Detailed results obtained from the precision test 14 Bi
11、bliography . 19 PD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 3 Foreword This document (CEN/TR 10362:2014) has been prepared by Technical Committee ECISS/TC 102 “Methods of chemical analysis for iron and steel”, the secretariat of which is held by SIS. Attention is drawn to the possibility that some of
12、the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. PD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 4 1 Scope This Technical Report specifies an electrothermal atomic absorption spectrometric met
13、hod for the determination of selenium in steels. The method is applicable to selenium contents between 0,000 4 % (m/m) and 0,02 % (m/m). 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dat
14、ed references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 648, Laboratory glassware - Single-volume pipettes (ISO 648) EN ISO 1042, Laboratory glassware - One-mark volumetric flasks (ISO 1042) EN IS
15、O 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696) 3 Principle Dissolution of a test portion in hydrochloric and nitric acids and dilution of the solution to a known volume. Introduction of a known volume of the solution into the electrothermal atomizer of an ato
16、mic absorption spectrometer. Measurement of the absorption of the 196,0 nm spectral line energy emitted by a selenium hollow-cathode lamp, using Zeeman effect background correction. Calibration by the standard addition technique. 4 Reagents During the analysis, use only reagents of recognised analyt
17、ical grade and only grade 3 water, as specified in EN ISO 3696. 4.1 Nitric acid, HNO3(20= 1,40 g/ml) 4.2 Hydrochloric acid, HCl (20= 1,19 g/ml) 4.3 Matrix modifiers The matrix modifiers described in 4.3.1 and 4.3.2 are recommended. Each laboratory has to investigate on its own equipment which of the
18、m is the most suitable, regarding sensitivity and recovery. 4.3.1 Palladium-nickel modifier Prepare a palladium solution (1 mg/ml Pd) by dissolving 167 mg of PdCl2in 100 ml of hot water and 1 ml of nitric acid (4.1). Prepare a nickel solution (1 mg/ml) by dissolving 1 g of nickel (Ni 99,999 %) in 20
19、 ml of water, 20 ml of nitric acid (4.1) and 5 ml of hydrochloric acid (4.1). Heat until the metal is dissolved. After cooling, transfer the solution into a 1 l one-mark volumetric flask, dilute to the mark with water and mix well. Into a 50 ml volumetric flask, mix 35 ml of the 1 mg/ml palladium so
20、lution with 15 ml of the 1 mg/ml nickel solution. This solution contains 700 g/ml Pd and 300 g/ml Ni. PD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 5 4.3.2 Palladium-magnesium modifier Prepare a PdCl2solution by dissolving 500 mg of PdCl2in 100 ml of hot water and 1 ml of nitric acid (4.1). Prepare a Mg
21、(NO3)2solution by dissolving 350 mg of Mg(NO3)2. 6H2O in 100 ml of water and 1 ml of nitric acid (4.1). Mix equal volumes of the PdCl2solution and the Mg(NO3)2solution. 4.4 Selenium standard solution, 1 g/l Weigh , to the nearest 0,001 g, 1 g of high purity selenium min 99,9 % (mass fraction), trans
22、fer into a 100 ml beaker and cover with a watch glass. Dissolve it in 35 ml of nitric acid (4.1). Heat to complete dissolution at a temperature just below the boiling point (approximately 150 C) during at least 30 minutes. After cooling, transfer the solution quantitatively into a 1 000 ml one-mark
23、volumetric flask, dilute to the mark with water and mix well. 1 ml of this solution contains 1 mg of selenium. 4.5 Selenium standard solution, 0,01 g/l Transfer 10,0 ml of selenium standard solution (4.4) into a 1 000 ml one-mark volumetric flask. Add 120 ml of hydrochloric acid (4.2) and 40 ml of n
24、itric acid (4.1). Dilute to the mark with water and mix well. 1 ml of this solution contains 0,01 mg of selenium. 4.6 Pure iron, containing less than 0,000 1 % (mass fraction) of selenium 5 Apparatus All volumetric glassware shall be Class A and calibrated, in accordance with ISO 648 or ISO 1042 as
25、appropriate. Before use, all glassware shall be cleaned by boiling with hydrochloric acid to remove any chemical contamination. 5.1 Auto sampler equipped with micropipettes of capacity 10 l to 50 l 5.2 Atomic absorption spectrometer and electrothermal atomizer This shall be equipped with a selenium
26、hollow-cathode lamp or an electrodeless discharge lamp and supplied with pure argon. The instrument shall be fitted with Zeeman effect background correction. An electrothermal atomizer equipped with a Lvov platform, mounted in a pyrolytically coated graphite tube, supplied with argon as purge gas, i
27、s recommended. The characteristic mass for selenium shall be less than 30 pg of selenium. 6 Sampling Sampling shall be carried out in accordance with EN ISO 14284 or with an appropriate national standard for steels. PD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 6 7 Procedure 7.1 Test portion According t
28、o the expected selenium content (x) of the test sample, weigh to the nearest 0,1 mg, a test portion as indicated in Table 1. Table 1 Mass of the test portion Expected selenium content (x) of the test sample (g/g) Mass of the test portion (mg) x 15 2 000 15 x 35 1 000 35 x 75 400 75 x 150 200 150 x 2
29、00 100 7.2 Blank test Carry out a blank test simultaneously with the determination, following the same procedure and using the same quantities of all reagents as used for the determination, but substituting pure iron (4.6) for the test portion. 7.3 Preparation of the test solution Transfer the test
30、portion (7.1) into a 250 ml beaker tall form. Cover the beaker with a watch glass and add 10 ml of water, 10 ml of nitric acid (4.1) and 30 ml of hydrochloric acid (4.2). Heat at a temperature just below the boiling point (approximately 150 C) during at least two hours. Allow to cool. If necessary,
31、filter through a medium texture filter paper and collect the filtrate in a 250 ml one-mark volumetric flask. Wash the filter paper several times with hot water and collect the washings in the same 250 ml volumetric flask. Allow to cool, dilute to the mark with water and mix. 7.4 Preparation of the s
32、tandard addition solutions for the test solution Into a series of 50 ml one-mark volumetric flasks introduce 25 ml aliquots of the test solution (7.3) and add the volumes of selenium standard solution (4.5) shown in Table 2. Dilute to the mark with water and mix. These solutions are labelled S1, S2,
33、 S3 and S4 respectively. Table 2 Standard addition solutions for the test solution Label of the solution Selenium standard solution volume l Concentration of selenium in the test addition solutions g/ml S1 0 0 S2 200 0,04 S3 400 0,08 S4 600 0,12 PD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 7 7.5 Prepar
34、ation of the standard addition solutions for the blank test Into a series of 50 ml one-mark volumetric flasks introduce 25 ml aliquots of the blank solution (7.2) and add the volumes of selenium standard solution (4.5) shown in Table 3. Dilute to the mark with water and mix. These solutions are labe
35、lled B1, B2, B3 and B4 respectively. Table 3 Standard addition solutions for the blank test Label of the solution Selenium standard solution volume l Concentration of selenium in the test addition solutions g/ml B1 0 0 B2 200 0,04 B3 400 0,08 B4 600 0,12 8 Measurements Set the required instrument pa
36、rameters and align the electrothermal atomiser according to the manufacturers instructions (see NOTE 1 and 2). Adjust the wavelength in the region of 196,0 nm to minimum absorbance. NOTE 1 The operating parameters for electrothermal atomic absorption spectrometry vary considerably from an instrument
37、 to another and much more than for flame atomic absorption spectrometry. Typical operating parameters are given in Annex A. Annex B details the instruments and the instrumental conditions used by the laboratories having participated to the interlaboratory test programme (see Clause10). Fill the auto
38、 sampler with the blank standard addition solutions (7.5), the test standard addition solutions (7.4) and the matrix-modifier (4.3.1 or 4.3.2). Inject sequentially 10 l of each of the solutions 7.5 and 7.4 and add to each solution 10 l of the matrix modifier (4.3.1 or 4.3.2). Measure the absorbance
39、of each solution at the adjusted wavelength. Correct the absorbances for background simultaneously. NOTE 2 In general the absorbance is measured by peak height or peak area. The determination by peak area is recommended. 9 Expression of results 9.1 Plotting of the standard addition graphs Plot the a
40、bsorbances corresponding to the blank standard addition solutions against the concentration of selenium added, expressed in g/ml. Plot the absorbances corresponding to the test standard addition solutions against the concentration of selenium added, expressed in g/ml. Use least squares regression me
41、thod to calculate the lines for the blank standard addition solutions and for the test standard addition solutions. PD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 8 9.2 Method of calculation Determine the concentrations of selenium, expressed in g/ml, in the test solution and in the blank test CSand CBas
42、 the two intercepts on the concentration axis (see 9.1). The difference (CS- CB) gives the net concentration of selenium in the test solution (solution S1). Calculate the selenium mass fraction, in per cent (%), as follows: SSeB( - ) x 2 x 250 x 100x 1000CWCm= where: WSeis the selenium mass fraction
43、 in per cent (%); CSis the selenium concentration in the test solution, in micrograms per millilitre (g/ml); CBis the selenium concentration in the blank test solution, in micrograms per millilitre (g/ml); m is the mass of the test portion, in milligrams (mg). 10 Precision Four laboratories in four
44、European countries participated in an inter laboratory test programme under the auspices of ECISS/TC 102/WG 3, involving three determinations of selenium at nine levels. Each laboratory carried out two determinations under repeatability conditions as defined in ISO 5725-1, i.e. one operator, same ap
45、paratus, identical operating conditions, same standard addition solutions and a minimum period of time. The third determination was carried out on a different day using the same apparatus with different standard addition solutions. Details on the samples used are given in Annex C and the results obt
46、ained are reported in Annex D. The sets of data available were too few for a statistical evaluation based on ISO 5725-2 and ISO 5725-3 and CEN/TR 10345. Only Mandels h and k statistics were used (see Figures D.1 and D.2) rather for illustrative purposes. Annex D also provides some considerations on
47、the data presented. 11 Test report The test report shall contain the following information: a) identification of the test sample; b) method used; c) results; d) any unusual characteristics noted during the determination; e) any operation not included in this Technical Report or in the document to wh
48、ich reference is made or regarded as optional; f) date of the test and/or date of preparation or signature of the test report; g) signature of the responsible person. PD CEN/TR 10362:2014CEN/TR 10362:2014 (E) 9 Annex A (informative) Typical operating parameters A.1 Typical conditions for the determi
49、nation of selenium by electrothermal atomic absorption spectrometry Injection volumes 10 l of the test standard addition solutions and of the blank standard addition solutions and 10 l of the matrix modifier solution; Matrix modifier Pd-Ni or Pd-Mg; Instrumental settings See Table A.1 Table A.1 Instrumental settings Wavelength nm Slit width nm Ashing temperature C Atomisation temperature C 196,0 0,7 500 2000 Background Correction: Zeeman effect; Typical temperature profile: see Table A.2; Table A.2 Typical temperature profile
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