1、BSI Standards Publication PD CEN/TR 10362:2014 Chemical analysis of ferrous materials Determination of selenium in steels Electrothermal atomic absorption spectrometric methodPD CEN/TR 10362:2014 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of CEN/TR 10362:20
2、14. The UK participation in its preparation was entrusted to Technical Committee ISE/102, Methods of Chemical Analysis for Iron and Steel. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary
3、 provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 84816 2 ICS 77.040.30; 77.080.20 Compliance with a British Standard cannot confer immunity from legal obligations. This Publish
4、ed Document was published under the authority of the Standards Policy and Strategy Committee on 30 November 2014. Amendments issued since publication Date Text affectedPD CEN/TR 10362:2014TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 10362 November 2014 ICS 77.040.30; 77.080.20 Engli
5、sh Version Chemical analysis 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 Anal
6、yse von Eisenwerkstoffen - 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 Austri
7、a, Belgium, Bulgaria, Croatia, 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,
8、 Switzerland, Turkey and 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 n
9、ational Members. Ref. No. CEN/TR 10362:2014 EPD CEN/TR 10362:2014 CEN/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 An
10、nex A (informative) Typical 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 fro
11、m the precision test 14 Bibliography . 19 PD CEN/TR 10362:2014 CEN/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 th
12、e possibility that some of 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 10362:2014 CEN/TR 10362:2014 (E) 4 1 Scope This Technical Report specifies an electrothermal atomic
13、absorption spectrometric method 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
14、for its application. For dated 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 volume
15、tric flasks (ISO 1042) EN ISO 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 elect
16、rothermal atomizer of an atomic 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 r
17、eagents of recognised analytical grade and only grade 3 water, as specified in EN ISO 3696. 4.1 Nitric acid, HNO 3( 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
18、 its own equipment which of them 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 PdCl 2in 100 ml of hot water and 1 ml of nitric acid (4.1). Prepare a nickel solution (1 mg/ml) by dissolving 1
19、 g of nickel (Ni 99,999 %) in 20 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 3
20、5 ml of the 1 mg/ml palladium solution 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 10362:2014 CEN/TR 10362:2014 (E) 5 4.3.2 Palladium-magnesium modifier Prepare a PdCl 2solution by dissolving 500 mg of PdCl 2in 100 ml of hot water and 1 ml
21、 of nitric acid (4.1). Prepare a Mg(NO 3 ) 2solution by dissolving 350 mg of Mg(NO 3 ) 2. 6H 2 O in 100 ml of water and 1 ml of nitric acid (4.1). Mix equal volumes of the PdCl 2solution and the Mg(NO 3 ) 2solution. 4.4 Selenium standard solution, 1 g/l Weigh , to the nearest 0,001 g, 1 g of high pu
22、rity selenium min 99,9 % (mass fraction), transfer 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 so
23、lution quantitatively into a 1 000 ml one-mark 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 1
24、20 ml of hydrochloric acid (4.2) and 40 ml of nitric 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 calibra
25、ted, in accordance with ISO 648 or ISO 1042 as 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 a
26、tomizer This shall be equipped with a selenium 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 gra
27、phite tube, supplied with argon as purge gas, is 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 10362:2014 CEN/TR 10362:201
28、4 (E) 6 7 Procedure 7.1 Test portion According to 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 00
29、0 15 x 35 1 000 35 x 75 400 75 x 150 200 150 x 200 100 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 Pre
30、paration of the test solution Transfer the test 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 a
31、t least two hours. Allow to cool. If necessary, 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 m
32、ark with water and mix. 7.4 Preparation of the standard 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 wat
33、er and mix. These solutions are labelled S1, S2, 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
34、/TR 10362:2014 CEN/TR 10362:2014 (E) 7 7.5 Preparation 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
35、mark with water and mix. These solutions are labelled 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
36、,12 8 Measurements Set the required instrument parameters 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
37、spectrometry vary considerably from an instrument 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 interlabora
38、tory test programme (see Clause10). Fill the auto 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 m
39、odifier (4.3.1 or 4.3.2). Measure the absorbance 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 Pl
40、otting of the standard addition graphs Plot the absorbances 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, e
41、xpressed in g/ml. Use least squares regression method to calculate the lines for the blank standard addition solutions and for the test standard addition solutions. PD CEN/TR 10362:2014 CEN/TR 10362:2014 (E) 8 9.2 Method of calculation Determine the concentrations of selenium, expressed in g/ml, in
42、the test solution and in the blank test C Sand C Bas the two intercepts on the concentration axis (see 9.1). The difference (C S- C B ) gives the net concentration of selenium in the test solution (solution S1). Calculate the selenium mass fraction, in per cent (%), as follows: S Se B( - ) x 2 x 250
43、 x 100x 1000 C W C m = where: W Seis the selenium mass fraction in per cent (%); C Sis the selenium concentration in the test solution, in micrograms per millilitre (g/ml); C Bis the selenium concentration in the blank test solution, in micrograms per millilitre (g/ml); m is the mass of the test por
44、tion, in milligrams (mg). 10 Precision Four laboratories in four 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 repeatabilit
45、y conditions as defined in ISO 5725-1, i.e. one operator, same apparatus, 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. Det
46、ails on the samples used are given in Annex C and the results obtained 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 ill
47、ustrative purposes. Annex D also provides some considerations on 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 operati
48、on not included in this Technical Report or in the document to which 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 10362:2014 CEN/TR 10362:2014 (E) 9 Annex A (informative) T
49、ypical operating parameters A.1 Typical conditions for the determination 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 temperat
