1、BSI Standards PublicationBS EN 15991:2015Testing of ceramic andbasic materials Directdetermination of massfractions of impurities inpowders and granules ofsilicon carbide by inductivelycoupled plasma opticalemission spectrometry (ICPOES) with electrothermalvaporisation (ETV)BS EN 15991:2015 BRITISH
2、STANDARDNational forewordThis British Standard is the UK implementation of EN 15991:2015.It supersedes BS EN 15991:2011 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee RPI/1, Refractory products and materials.A list of organizations represented on this
3、committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 83140 9ICS 81.06
4、0.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 November 2015.Amendments/corrigenda issued since publicationDate Text affectedBS EN 15991:2015EUROPEAN STAND
5、ARD NORME EUROPENNE EUROPISCHE NORM EN 15991 November 2015 ICS 81.060.10 Supersedes EN 15991:2011English Version Testing of ceramic and basic materials - Direct determination of mass fractions of impurities in powders and granules of silicon carbide by inductively coupled plasma optical emission spe
6、ctrometry (ICP OES) with electrothermal vaporisation (ETV) Essais sur matriaux cramiques et basiques - Dtermination directe des fractions massiques dimpurets dans les poudres et les granuls de carbure de silicium par spectroscopie dmission optique plasma induit par haute frquence (ICP OES) avec vapo
7、risation lectrothermique (ETV) Prfung keramischer Roh- und Werkstoffe - Direkte Bestimmung der Massenanteile von Spurenverunreinigungen in pulver- und kornfrmigem Siliciumcarbid mittels optischer Emissionsspektroskopie mit induktiv gekoppeltem Plasma (ICP OES) und elektrothermischer Verdampfung (ETV
8、) This European Standard was approved by CEN on 3 October 2015. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical re
9、ferences concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a
10、CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedo
11、nia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPI
12、SCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15991:2015 EBS EN 15991:2015EN 15991:2015 (E) 2 Contents Page European foreword . 3 1 Sc
13、ope 4 2 Principle . 4 3 Spectrometry 4 4 Apparatus . 6 5 Reagents and auxiliary material 6 6 Sampling and sample preparation 7 7 Calibration . 7 8 Procedure. 8 9 Wavelength and working range . 9 10 Calculation of the results and evaluation . 9 11 Reporting of results . 10 12 Precision 10 12.1 Repeat
14、ability 10 12.2 Reproducibility . 10 13 Test report 10 Annex A (informative) Results of interlaboratory study 11 Annex B (informative) Wavelength and working range . 16 Annex C (informative) Possible interferences and their elimination 17 Annex D (informative) Information regarding the evaluation of
15、 the uncertainty of the mean value 20 Annex E (informative) Commercial certified reference materials 21 Annex F (informative) Information regarding the validation of an analytical method based on liquid standards in the example of SiC and graphite. 22 Bibliography . 24 BS EN 15991:2015EN 15991:2015
16、(E) 3 European foreword This document (EN 15991:2015) has been prepared by Technical Committee CEN/TC 187 “Refractory products and materials”, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text
17、or by endorsement, at the latest by May 2016 and conflicting national standards shall be withdrawn at the latest by May 2016. 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 ide
18、ntifying any or all such patent rights. This document supersedes EN 15991:2011. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republi
19、c, 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 the United Kingdom. BS EN 1
20、5991:2015EN 15991:2015 (E) 4 1 Scope This European Standard defines a method for the determination of the trace element concentrations of Al, Ca, Cr, Cu, Fe, Mg, Ni, Ti, V and Zr in powdered and granular silicon carbide. Dependent on element, wavelength, plasma conditions and weight, this test metho
21、d is applicable for mass contents of the above trace contaminations from about 0,1 mg/kg to about 1 000 mg/kg, after evaluation also from 0,001 mg/kg to about 5 000 mg/kg. NOTE 1 Generally for optical emission spectrometry using inductively coupled plasma (ICP OES) and electrothermal vaporization (E
22、TV) there is a linear working range of up to four orders of magnitude. This range can be expanded for the respective elements by variation of the weight or by choosing lines with different sensitivity. After adequate verification, the standard is also applicable to further metallic elements (excepti
23、ng Rb and Cs) and some non-metallic contaminations (like P and S) and other allied non-metallic powdered or granular materials like carbides, nitrides, graphite, soot, coke, coal, and some other oxidic materials (see 1, 4, 5, 6, 7, 8, 9 and 10). NOTE 2 There is positive experience with materials lik
24、e, for example, graphite, B4C, Si3N4,BN and several metal oxides as well as with the determination of P and S in some of these materials. 2 Principle The sample material, crushed if necessary, is evaporated in an argon- carrier-gas stream in a graphite boat in the graphite tube furnace of the ETV un
25、it. The evaporation products containing the element traces are transported as a dry aerosol into the plasma of the ICP-torch and there excited for the emission of optical radiation. In a simultaneous emission spectrometer in, for example Paschen-Runge- or Echelle-configuration, the optical radiation
26、 is dispersed. The intensities of suited spectral lines or background positions are registered with applicable detectors like photomultipliers (PMT), charge coupled devices (CCD), charge injection devices (CID), and serial coupled devices (SCD). By comparison of the intensities of the element-specif
27、ic spectral lines of the sample with calibration samples of known composition, the mass fractions of the sample elements are determined. 3 Spectrometry Optical emission spectrometry is based on the generation of line spectra of excited atoms or ions, where each spectral line is associated with an el
28、ement and the line intensities are proportional to the mass fractions of the elements in the analysed sample. Contrary to the wet chemical analysis from dilution in ICP OES the classical sample digestion is replaced by electrothermal vaporization at high temperatures in a graphite furnace. By a suit
29、able design of the furnace (see Figures 1 and 2) and a suited gas regime in the transition area graphite tube / transport tube (see Figure 1), it is ensured that the sample vapour is carried over into a form that is to transport effectively (see 5, 6, 7, 8, 10). Carbide forming elements, for example
30、 titanium, zirconium, that are incompletely or not evaporating need a suitable reaction gas (halogenating agent) to be converted into a form that is easy to transport (see 1, 3, 5 and 10.) Dichlorodifluoromethane (CCl2F2) shall be used as halogenating agent. Compared to other halogen containing carb
31、on compounds CCl2F2provides optimum analyte release and transport efficiency. CCl2F2is required for simultaneous determination of the elements listed in Clause 1. The results of the interlaboratory study (see Annex A) were obtained using CCl2F2as reaction gas. The dry aerosol is introduced into the
32、ICP plasma by the injector tube and there excited for the emission of light (see Figure 1, Figure 2 and Figure 3). BS EN 15991:2015EN 15991:2015 (E) 5 Key 1 graphite tube with boat and sample 5 bypass gas (Ar) 2 carrier gas (Ar) 6 aerosol 3 reaction gas (CCl2F2) 7 to the ICP torch 4 shield gas (Ar)
33、Figure 1 Schematic configuration of the ETV-gas regime with the gas flows carrier-gas, bypass-gas, reaction-gas and shield-gas Key 1 graphite tube furnace 6 bypass-gas (Ar) 2 pyrometer 7 aerosol 3 carrier gas (Ar) + reaction gas (CCl2F2) 8 transport tube 4 solid sample 9 ICP-torch 5 vapour 10 power
34、supply 0 A to 400 A Figure 2 Schematic design of the ETV-ICP-combination with an axial plasma (example) BS EN 15991:2015EN 15991:2015 (E) 6 Key 1 Al2O3-transport tube 5 carrier gas evaporated sample 2 Al2O3-transition ring 6 bypass gas 3 nozzle 7 gas mixture in laminar flow 4 graphite tube Figure 3
35、Schematic configuration of the transition area between graphite- and transport-tube NOTE Figure 1, Figure 2 and Figure 3 show a well-established commercial instrument. 4 Apparatus 4.1 Common laboratory instruments and laboratory instruments according to 4.2 to 4.7. 4.2 ICP-emission spectrometer, sim
36、ultaneous, preferably with the possibility to register transient emission signals and suited for the synchronised start of ETV vaporization cycle and signal registration. NOTE Especially for changing matrices the measurement of the spectral background near the analysis lines is beneficial, because b
37、y this the systematic and stochastic contributions of the analysis uncertainty can be decreased, the latter only by simultaneous measurement of the background. The use of spectrometers equipped with area- or array-detectors is an advantage in such cases as they allow a simultaneous background measur
38、ement, in addition to their possibility to save a lot of time in the analysis cycle. 4.3 Electrothermal vaporization system with graphite furnace with suited transition zone graphite tube / transport tube for optimised aerosol formation, to be connected to the injector tube of the ICP torch by a tra
39、nsport tube for example made of corundum, PTFE, PFA, PVC (cross-linked), with controlled gas flows (preferably with mass-flow-control) and furnace control (preferably with continuous online-temperature control of the graphite boat) for a reproducible control of the temperature development. 4.4 Tweez
40、ers, self-closing, made of a material preventing contamination. 4.5 Micro spatula, made of a material preventing contamination. 4.6 Microbalance, capable of reading to the nearest 0,01 mg. NOTE A microbalance with a direct reading of 0,001 mg is advantageous. 4.7 Mill or crusher, free of contaminati
41、on, for example mortar made of a material that does not contaminate the sample with any of the analytes to be determined. 5 Reagents and auxiliary material Only analytical grade reagents shall be used unless stated otherwise. BS EN 15991:2015EN 15991:2015 (E) 7 5.1 Sample boats of graphite (spectral
42、 grade) adapted in size to the graphite tube of the ETV, baked out for the necessary purity. 5.2 Calibration samples with well-defined mass fractions of trace-impurities, preferably certified reference materials (CRM). NOTE For silicon nitride, silicon carbide and boron carbide certified reference m
43、aterial is available for main-, minor- and trace-components. (For CRMs, see Annex E.) 5.3 Calibration solutions, made of tested stock solutions of the elements to be analysed. 5.4 Reaction gas, Dichlorodifluoromethane (CCl2F2) NOTE Dichlorodifluoromethane is the most effective reaction gas, some alt
44、ernative reaction gases have serious disadvantages. According to the EU-regulation (see 12) of materials influencing the ozone layer, this chemical product is allowed for laboratory use and for the use as a starting substance. CCl2F2is completely decomposed in the hot graphite furnace and in the dow
45、nstream inductively coupled plasma. The use of CCl2F2for laboratory and analysis purposes is subject to registration at the European Commission. 5.5 Argon purity 99,99 % (volume fraction). 6 Sampling and sample preparation Sampling shall be performed in a way that the sample to be analysed is repres
46、entative for the total amount of material, using for example ISO 5022 13, ISO 8656-1 14, EN ISO 21068-1 15, but this list is not exhaustive. If the sample is not received in a dry state, it shall be dried at (110 10) C until constant mass is achieved (0,5 % variation). The sample is then cooled down
47、 to room temperature and stored in a desiccator. NOTE Drying for 2 h is normally sufficient. It is critical that the sample material is on hand at a particle size of 50 m; eventually it shall be broken up and homogenized, if necessary. For this a crushing device suited for the analysis goal shall be
48、 applied. For porous materials, it shall be checked out if it is necessary to break them up. Breaking up is necessary if the transient analysis signals show an unusual long decay (tailing). 7 Calibration The calibration shall be performed for each measuring cycle with calibration samples with define
49、d analyte concentrations. The procedure shall be carried out in accordance with Clause 8. The calibration shall be carried out over a range adapted to the analytical task. NOTE 1 This can be achieved by different masses of the same calibration sample or same masses of different calibration samples with different analyte concentration or by a combination of both possibilities. Because of the low weights used and therefore the resulting spread, the number of (calibration) measurements should take account of the
