1、BRITISH STANDARD BS EN 27627-6:1993 ISO 7627-6: 1985 Hardmetals Chemical analysis by flame atomic absorption spectrometry Part6: Determination of chromium in contents from0.01 to2% (m/m) The European Standard EN27627-6:1992 has the status of a BritishStandard UDC 669.018.25:620.1:543.422:546.76BSEN2
2、7627-6:1993 This BritishStandard, having been prepared under the directionof the Iron and Steel Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 15June1993 BSI 01-2000 The following BSI references relate to the work on this standard: Committe
3、e reference ISM/65 Special announcement in BSINews January1993 ISBN 0 580 21929 1 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austri
4、a Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland T
5、echnological Institute of Iceland Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade S
6、pain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom BritishStandards Institution Amendments issued since publication Amd. No. Date CommentsBSEN27627-6:1993 BSI 01-2000 i Contents Page Coope
7、rating organizations Inside front cover National foreword ii Foreword 2 1 Scope and field of application 3 2 Reference 3 3 Reagents 3 4 Procedure 3 5 Expression of results 4 Annex ZA (normative) Normative references to international publications with their relevant European publications 5 National a
8、nnex NA (informative) Committees responsible Inside back cover National annex NB (informative) Cross-reference Inside back cover Table 1 Test portion, instrumental parameters and characteristics of calibration functions 3 Table 2 Permissible tolerances 4 Table 3 Rounding of results 4BSEN27627-6:1993
9、 ii BSI 01-2000 National foreword This BritishStandard has been prepared under the direction of the Iron and SteelStandards Policy Committee and is the English language version of EN27627-6:1993 Hardmetals Chemical analysis by flame atomic absorption spectrometry Part6: Determination of chromium in
10、contents from0,01 to2%(m/m), published by the European Committee for Standardization (CEN). It is identical with ISO7627-6:1985, prepared by Technical Committee119, Powder metallurgy, of the International Organization for Standardization (ISO) with the active participation of the UK. This BritishSta
11、ndard supersedes BS5600-4.17.6:1986, which is withdrawn and from which it differs by the addition of Annex ZA. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a Britis
12、h Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had
13、 amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN27627-6 April1993 UDC 669.018.25:620.1:543.422:546.76 Descriptors: Powder metallurgy, hard metals, chemical analysis, determination of content, transi
14、tion metals, chromium, atomic absorption spectrophotometry English version Hardmetals Chemical analysis by flame atomic absorption spectrometry Part6: Determination of chromium in contents from0,01 to2% (m/m) (ISO7627-6:1985) Mtaux-durs Analyse chimique par spectromtrie dabsorption atomique dans la
15、flamme Partie6: Dosage du chrom des teneurs comprises entre0,01 et2% (m/m) (ISO7627-6:1985) Hartmetalle Chemische Analyse durch Flammenatomabsorptionsspektrometrie Teil6: Bestimmung des Chromgehaltes von0,01 bis2% (m/m) (ISO7627-6:1985) This European Standard was approved by CEN on1993-04-02. CEN me
16、mbers 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 references concerning such national standards may be obtained on applica
17、tion to the Central Secretariat 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 CEN member into its own language and notified to the Central Secretariat has the
18、 same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European Committee for Standardiz
19、ation Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1993 Copyright reserved to CEN members Ref.No.EN27627-6:1993EEN27627-6:1993 BSI 01-2000 2 Foreword In1992, ISO7627-6:1985 Hardmetals Chemical analysis by flame atomic absorpti
20、on spectrometry Part6: Determination of chromium in contents from0,01 to2% (m/m) was submitted to the CEN Primary Questionnnaire procedure. Following the positive result of the CEN/CS Proposal ISO7627-6:1985 was submitted to the CEN Formal Vote. The result of the Formal Vote was positive. This Europ
21、ean Standard shall be given the status ofa national standard, either by publication of anidentical text or by endorsement, at the latest by October1993, and conflicting national standards shall be withdrawn at the latest by October1993. According to the Internal Regulations of CEN/CENELEC, the follo
22、wing countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom.EN27627-6:1993 BSI 01-2000 3 1 Scope and field of application Th
23、is part of ISO7627 specifies the method to be used for the determination of the chromium content of hardmetals within the range0,01 to2%(m/m) by flame atomic absorption spectrometry. General requirements concerning the field of application, principle, interfering elements, apparatus, sampling and te
24、st report are given in ISO7627-1. 2 Reference ISO7627-1, Hardmetals Chemical analysis by flame atomic absorption spectrometry Part1:General requirements. 3 Reagents 3.1 Potassium pyrosulfate 3.2 Perchloric acid, 1,54 or1,67g/ml. 3.3 Ammonium citrate, solution. Dissolve100g of citric acid in1500ml of
25、 water and add400ml of ammonia solution( 0,91g/ml). 3.4 Hydrogen peroxide, 30%(m/m). 3.5 High purity stock solution, for calibration purposes, containing1,000g of chromium per litre. NOTEThis value is understood to establish a maximum limit of1,0005g and a minimum limit of0,9995g. 4 Procedure 4.1 Te
26、st portion Weigh, to the nearest0,001g, the relevant amount of the test sample indicated in Table 1. Transfer it to a100ml conical flask (preferably of quartz). NOTEIn this special case, the sample shall pass a0,18mm sieve. 4.2 Dissolution of the test portion Add5g of the potassium pyrosulphate(3.1)
27、 and a few drops of the perchloric acid(3.2) to the beaker containing the test portion(4.1) and heat gently until the test portion is completely dissolved. Add40ml of the ammonium citrate solution(3.3), and about0,5ml of the hydrogen peroxide(3.4). Then transfer the solution to a100ml polypropylene
28、one-mark volumetric flask and dilute to the mark. 4.3 Dilution volume Prepare the relevant dilution volume for the analysis according to Table 1 as follows: 4.3.1 Dilution volume100ml: use the solution in4.2. 4.3.2 Dilution volume500ml: transfer20ml of the solution in4.2 to a100ml polypropylene one-
29、mark volumetric flask and dilute to the mark. 4.4 Preparation of calibration and blank solutions 4.4.1 Prepare at least six solutions according to4.2 with a matrix composition as similar as possible to the test portion to be analysed, but without making up to volume. Then add increasing volumes of t
30、he properly diluted stock solution of chromium(3.5) according to the concentration range to be covered. Make up to100ml and mix. 4.4.2 Also prepare calibration solutions with a diluted matrix in accordance with4.3 for dilution volumes of500ml, if necessary. 4.4.3 Prepare a blank solution (see4.4.1)
31、without the addition of chromium. Table 1 Test portion, instrumental parameters and characteristics of calibration functions Content Test portion Dilution volume (V) for the test portion a Oxidant Wavelength Reciprocal sensitivity, for1% absorption a Linear range a % g ml nm 4g/ml % 0,01 to0,1 0,1 t
32、o0,5 0,1 to0,5 0,5 to2 0,500 0,500 0,100 0,100 100 500 100 500 N 2 O N 2 O N 2 O N 2 O 357,9 357,9 357,9 357,9 0,11 0,11 0,11 0,11 0 to0,12 0,1 to0,5 0,1 to0,5 0,4 to2 a Guidelines for information only.EN27627-6:1993 4 BSI 01-2000 4.5 Adjustment of the atomic absorption spectrometer SAFETY PRECAUTIO
33、N: Follow the manufacturers recommendation on igniting and extinguishing the flame. Optimize the response of the instrument at the wavelength given (see Table 1). Preheat the burner for about5min and then adjust the fuel and correct the burner to obtain maximum absorption while aspirating a calibrat
34、ion solution. Make sure that the absorbance reading is not drifting. Aspirate water and set the initial reading to zero absorbance. 4.6 Atomic absorbance measurements 4.6.1 Aspirate first the blank solution and then the calibration and test solutions consecutively and record the readings. Aspirate w
35、ater between each solution. Make at least two measurements for each solution. If a build-up of solids occurs on the burner slit, it will cause a decrease of sensitivity and must be removed. 4.6.2 Prepare a calibration curve by plotting the obtained absorbance values of the calibration solutions corr
36、ected for the blank against the concentration, in milligrams per litre, of chromium. 4.6.3 Convert the absorbance values of the test solutions corrected for the blank to milligrams of chromium per litre by means of the calibration curve. 5 Expression of results 5.1 Calculation The chromium content,
37、expressed as a percentage by mass, is given by the formula where c is the concentration, in milligrams per litre, of chromium in the test solution; V is the dilution volume, in millilitres; m is the mass, in grams, of the test portion. 5.2 Permissible tolerances The deviations between three independ
38、ent determinations shall not exceed the values shown in Table 2. Table 2 Permissible tolerances 5.3 Final result Report the arithmetical mean of acceptable determinations rounded to the nearest value as shown in Table 3. Table 3 Rounding of results If the chromium content is below0,01% (m/m), report
39、 it as less than0,01% (m/m). cV 10 4 m - Content %(m/m) Range % (m/m) from0,01 to0,20 over0,20 to2 0,012 0,06 (content) Content % (m/m) Round to the nearest % (m/m) from0,01 to0,20 over0,20 to2 0,01 0,05EN27627-6:1993 BSI 01-2000 5 Annex ZA (normative) Normative references to international publicati
40、ons with their relevant European publications This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent
41、amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). Publication Year Title EN/HD Year ISO7627-1 Hardmeta
42、ls Chemical analysis by flame atomic absorption spectrometry Part1: General requirements EN27627-16 blankBSEN27627-6:1993 BSI 01-2000 National annex NA (informative) Committees responsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Iron and Ste
43、el Standards Policy Committee (ISM/-) to Technical Committee ISM/65, upon which the following bodies were represented: British Hardmetal Association Federation of British Engineers (Test Manufacturers) Society of Motor Manufacturers and Traders Limited Coopted member National annex NB (informative)
44、Cross-reference Publication referred to Corresponding BritishStandard ISO7627-1:1983 BS EN27627 Hardmetals Chemical atomic absorption spectrometry Part1:1993 General requirementsBS EN 27627-6:1993 ISO 7627-6: 1985 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the ind
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