CEN/TR 10362:2014

SLOVENSKI STANDARD
01-februar-2015
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Chemical analysis of ferrous materials - Determination of selenium in steels -
Electrothermal atomic absorption spectrometric method
Chemische Analyse der Eisen und Stahlwerkstoffe - Bestimmung des Selengehaltes in
Stahl
Analyse chimique des produits ferreux - Détermination du sélénium dans les aciers -
Méthode par spéctrométrie d'absorption atomique éléctrothermique
Ta slovenski standard je istoveten z: CEN/TR 10362:2014
ICS:
77.040.30 Kemijska analiza kovin Chemical analysis of metals
77.080.20 Jekla Steels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 10362
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
November 2014
ICS 77.040.30; 77.080.20
English Version
Chemical analysis of ferrous materials - Determination of
selenium in steels - Electrothermal atomic absorption
spectrometric method
Analyse chimique des produits ferreux - Détermination du Chemische Analyse von Eisenwerkstoffen - Bestimmung
sélénium dans les aciers - Méthode par spectrométrie von Selen in Stahl - Spektrometrisches Verfahren mit
d'absorption atomique électrothermique 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, 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, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR 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 Ref. No. CEN/TR 10362:2014 E
worldwide for CEN national Members.

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) 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 from the precision test . 14
Bibliography . 19

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 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.
1 Scope
This Technical Report specifies an electrothermal atomic 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 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 volumetric 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 electrothermal 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 reagents of recognised analytical grade and only grade 3 water, as specified in
EN ISO 3696.
4.1 Nitric acid, HNO (ρ = 1,40 g/ml)
3 20
4.2 Hydrochloric acid, HCl (ρ = 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 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 in 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 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 solution with 15 ml of the 1 mg/ml nickel
solution. This solution contains 700 μg/ml Pd and 300 μg/ml Ni.
4.3.2 Palladium-magnesium modifier
Prepare a PdCl solution by dissolving 500 mg of PdCl in 100 ml of hot water and 1 ml of nitric acid (4.1).
2 2
Prepare a Mg(NO ) solution by dissolving 350 mg of Mg(NO ) . 6H O in 100 ml of water and 1 ml of nitric
3 2 3 2 2
acid (4.1).
Mix equal volumes of the PdCl solution and the Mg(NO ) solution.
2 3 2
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)], 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 solution 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 120 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 calibrated, 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 μl to 50 μl
5.2 Atomic absorption spectrometer and electrothermal atomizer
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 L’vov platform, mounted in a pyrolytically coated graphite 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.
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 Mass of the test portion
the test sample (mg)
(μg/g)
x < 15 2 000
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 Preparation 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 at 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 mark 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 water 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 Concentration of selenium
solution volume in the test addition
solutions
μl
μg/ml
S1 0 0
S2 200 0,04
S3 400 0,08
S4 600 0,12
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 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 Concentration of selenium
solution volume in the test addition
solutions
μl
μg/ml
B1 0 0
B2 200 0,04
B3 400 0,08
B4 600 0,12
8 Measurements
Set the required instrument parameters and align the electrothermal atomiser according to the manufacturer's
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 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 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 μl of each of the solutions 7.5 and 7.4 and add to each solution 10 μl of the matrix
modifier (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 Plotting of the standard addition graphs
Plot the absorbances corresponding to the blank standard addition solutions against the concentration of
selenium added, expressed in μg/ml.
Plot the absorbances corresponding to the test standard addition solutions against the concentration of
selenium added, expressed in μg/ml.
Use least squares regression method to calculate the lines for the blank standard addition solutions and for
the test standard addition solutions.
SIST-TP CEN
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