1、CEN ENt27627-4 93 W 3404589 0047387 600 W EUROPEAN STANDARD EN 27627-4 NORME EUROPENNE EUROPAISCHE NORM April 1993 UDC 669.018.25 : 620.1 : 543.422 Descriptors: Powder metallurgy, hard metals, chemical analysis, determination of content, transition metals, molybdenum, titanium, vanadium, spectrometr
2、ic analysis, atomic absorption spectrophotometry English version Hardmetals - Chemical analysis by flame atomic absorption spectrometry - Part 4 : Determination of molybdenum, titanium and vanadium in contents from 0,Ol to 0,5 % (m/m) (IS0 7627-4 : 1983) Mtaux-durs - Analyse chimique par spectromtri
3、e dabsorption atomique dans la flamme - Partie 4: Dosages du molybdne, du titane et du vanadium des teneurs Hartmetalle - Chemische Analyse durch Flammenatomabsorptionsspektrometrie - %il 4: Bestimmung des Molybdn-, Titan- und Vanadiumgehaltes von 0,Ol bis 0,5 % (mh) comprises entre 0,Ol et 0,5 % (m
4、h) (IS0 7627-4 1983) (IS0 7627-4 : 1983) This European Standard was approved by CEN on 1993-04-02. CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-t
5、o-date lists and bibliographical references concerning such national standards may be obtained on application 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
6、 the responsibility of a CEN member into its own language and notified to the Central Secretariat has the 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, Netherlan
7、ds, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 0 1993 Copyright reserved to CEN members Ref. No. EN 27627-4 : 1993 E
8、 CEN ENx27627-4 93 3404589 0047L88 547 m Page 2 EN 27627-4 : 1993 Foreword In 1992, IS0 7627-4 : 1983 Hardmetals - Chemical analysis by flame atomic absorption spectrometry - Pbcrt 4: Detemnination of molybden, titanium and vanadium in contents fm O, O1 to O, 5 % (Wm) was submitted to the CEN Primar
9、y Questionnnaire procedure. Following the positive result of the CEN/CS Proposal IS0 7627-4 : 1983 was submitted to the CEN Formal Vote. The result of the Formal Vote was positive. This European Standard shall be given the status of a national standard, either by publication of an identical text or
10、by endorsement, at the latest by October 1993, and conflicting national standards shall be withdrawn at the latest by October 1993. According to the Internal Regulations of CENKENELEC, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France,
11、Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. NOTE. The European references to international publications are given in annex ZA (normative). Page 3 EN 27627-4 : 1993 1 Scope and field of application 4.2 Dissolution
12、 of the test portion This part of IS0 7627 specifies the method to be used for the determination of molybdenum, titanium and vanadium con- tents of hardrnetals within the range 0.01 to 0,5 % (mlm) by flame atomic absorption spectrometry. General requirements concerning the field of application, prin
13、- ciple, interfering elements, apparatus, sampling and test report are given in IS0 7627/1. Add 10 ml of water, 5 ml of the hydrofluoric acid (3.1). and then 5 ml of the nitric acid (3.2), drop by drop, to the beaker containing the test portion (4.1) and heat gently until the test portion is complet
14、ely dissolved. Add 10 ml of the caesium chloride solution (3.4) and 10 ml of the ammonium fluoride solution (3.3). Then transfer the solution totally to a 100 ml polypropylene one-mark volumetric flask and dilute to the mark. 2 Reference 4.3 Dilution volume IS0 7627/1, Hardmetals - Chemical analysis
15、 by fiame atomic absorption spectrometry - Part I: General requirements. Prepare the relevant dilution volume for the analysis according to table i as follows: 3 3.1 3.2 Reagents Hydrofluoric acid, e 1,12 g/ml. Nitric acid, e 1,42 g/ml. 4.3.1 Dilution volume 100 ml: use the solution in 4.2. 4.3.2 Th
16、e concentration of the solution may be reduced by a factor of 10 for instruments of higher sensitivity by transferring 10 ml of the solution in 4.2 to a 100 ml polypropylene one-mark volumetric flask. Add 10 ml of the caesium chloride solution (3.4). Add 10 rnl of the ammonium fluoride solution (3.3
17、) and 3.3 Ammonium fluoride, 0,l g/ml colution. dilute to the mark. 3.4 Caesium chloride, 0,Ol g/ml solution. 4.4 Preparation of calibration and blank solutions 3.5 High-purity stock solutions, for calibration purposes for each element to be determined, containing 1,m g of the element per litre. NOT
18、E - This value is understood to establish a maximum limit of 1 ,o00 5 g and a minimum limit of 0,999 5 g. 4.4.1 Prepare at least Six SOlUtiOnS according to 4.2 with a matrix composition as similar as possible to the test portion to be analysed, but without making up to volume. Then add in- creasing
19、Voumes Of property diluted stock SOlUtiOnS Of the elements to be determined according to the concentration ranges to be covered. Make up to 100 ml and mix. 4 Procedure 4.1 Test portion 4.4.2 Also prepare calibration solutions with a diluted matrix in accordance with 4.3 for dilution volumes of 1 o00
20、 ml, if necessary. Weigh, to the nearest 0,001 g, approximately 1 g of the test sample. Transfer it to a 100 ml polytetrafluorethylene beaker or a beaker of other suitable material. Cover the beaker. 4.4.3 Prepare one or more blank solutions (see 4.4.1 1 without the addition of the relevant element
21、to be determined. CEN EN+27b27-4 93 3404589 0047390 LT5 m Reciprocal sensitivity, Oxidant Wavelength for 1 % absorption” nrn Cig/ml 313.3 0.3 313,3 6 364,3 1 ,o 318.4 03 NZO N2O NZO NZO Page 4 EN 27627-4 : 1993 Linear range” % 0,003 to 0.1 0,06 to 10,o 0.03 to 0.5 0,008 to 0,5 Table 1 - Instrumental
22、 parameters and characteristics of calibration functions Element Dilution volume VI for 1 g test portion” mi Mo Ti v Content % mlm) from 0.01 to O, 1 over 0,l to 0,5 100 100 100 100 Round to the nearest % imlm 0.01 0,m 1) Guidelines for information only. NOTES 1 Use a fuel-rich flame. 2 Adjust the b
23、urner head at right angles to the light beam or dilute the solutions appropriately. 3 Use of the triplet. 4.5 Adjustment of the atomic absorption spectrometer SAFETY PRECAUTION : Follow the manufacturers recommendation on igniting and extinguishing the flame. Optimize the response of the instrument
24、at the wavelength given for the element being determined. See table 1. Preheat the burner for about 5 min and then adjust the fuel and correct the burner to obtain maximum absorption while aspirating a calibration solution. Make sure that the absorbance reading is not drifting. Aspirate water and se
25、t the initial reading to zero absorbance. 5 Expression of results 5.1 Calculation The element content, expressed as a percentage by mass, is given by the formula cx v 104 x m where c is the concentration, in milligrams per litre, of the element of the test solution; V is the dilution volume, in mill
26、ilitres; m is the mass, in grams, of the test portion. 5.2 Permissible tolerances 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 water between each solution. Make at least two meas
27、urements 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 ab- sorbance values of the calibration solutions corrected for the blank against the concentration, i
28、n milligrams per litre, of the element. 4.6.3 Convert the absorbance values of the test solutions corrected for the blank to milligrams of the element per litre by means of the calibration curve. Notes 1 and 2 The deviations between three independent determinations shall not exceed 0,2 times the ele
29、ment content in per cent (absolute value). 5.3 Final result Report the arithmetical mean of acceptable determinations rounded to the nearest value as shown in table 2. If the element content is below 0,Ol % m/rn), report it as less than 0.01 % (m/m). CEN EN*27627-4 93 3404587 0047191 031 = Page 5 BS
30、 EN 27627-4 : 1993 Annex ZA (normative) Normative references to international publications 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 i
31、n the text and the publications are listed hereafter. For dated references, subsequent 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 IS0 7627-1 Hardmetals - Chemical analysis by flame EN 27627-1 atomic absorption spectrometry - Part 1 : General requirements i
