1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 14938-2:2010Copper and copper alloys Determination of bismuthcontentPart 2: Flame atomic absorptionspectrometric method (FAAS)BS EN 14938-2:2010 BRITISH STANDARDNational fo
2、rewordThis British Standard is the UK implementation of EN 14938-2:2010.It supersedes DD CEN/TS 14938-2:2006 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee NFE/34, Copper and copper alloys.A list of organizations represented on this committee can beobt
3、ained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 66407 6ICS 77.120.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This
4、British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2010Amendments issued since publicationDate Text affectedBS EN 14938-2:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14938-2 July 2010 ICS 77.120.30 Supersedes CEN/TS 14938-2:2006
5、English Version Copper and copper alloys - Determination of bismuth content - Part 2: Flame atomic absorption spectrometric method (FAAS)Cuivre et alliages de cuivre - Dtermination du bismuth - Partie 2: Mthode par spectromtrie dabsorption atomique dans la flamme (SAAF) Kupfer und Kupferlegierungen
6、- Bestimmung des Bismutgehaltes - Teil 2: Flammenatomabsorptionsspektrometrisches Verfahren (FAAS) This European Standard was approved by CEN on 12 June 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard th
7、e status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, Germ
8、an). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus
9、, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMI
10、T EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14938-2:2010: EBS EN 14938-2:2010EN 14938-2:2010 (E) 2 Contents Pag
11、e Foreword 31 Scope 42 Normative references 43 Principle 44 Reagents . 45 Apparatus . 56 Sampling . 57 Procedure . 58 Expression of results 89 Precision . 910 Test report 9Bibliography 11BS EN 14938-2:2010EN 14938-2:2010 (E) 3 Foreword This document (EN 14938-2:2010) has been prepared by Technical C
12、ommittee CEN/TC 133 “Copper and copper alloys”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2011, and conflicting national standards shall be w
13、ithdrawn at the latest by January 2011. 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. This document supersedes CEN/TS 14938-2:2006.
14、Within its programme of work, Technical Committee CEN/TC 133 requested CEN/TC 133/WG 10 “Methods of analysis“ to prepare the revision of the following document: CEN/TS 14938-2:2006, Copper and copper alloys Determination of bismuth content Part 2: FAAS method In comparison with the first edition of
15、CEN/TS 14938-2:2006, the following significant technical changes were made: Revision from a Technical Specification to a European Standard; Subclause 7.4.1.1 - text added; Clause 9 Precision - completely revised. This is one of two parts of the standard for the determination of bismuth content in co
16、pper and copper alloys. The other part is: EN 14938-1, Copper and copper alloys Determination of bismuth content Part 1: Spectrophotometric method Part 1 will be the subject of future work. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following coun-
17、tries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxem-bourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slo
18、venia, Spain, Sweden, Switzerland and United Kingdom. BS EN 14938-2:2010EN 14938-2:2010 (E) 4 1 Scope This European Standard specifies a flame atomic absorption spectrometric method (FAAS) for the determination of the bismuth content of copper and copper alloys in the form of unwrought, wrought and
19、cast products. The method is applicable to products having bismuth mass fractions between 0,01 % and 0,25 %. 2 Normative references The following referenced documents are indispensable for the application of this European Standard. For dated references, only the edition cited applies. For undated re
20、ferences, the latest edition of the referenced document (including any amendments) applies. ISO 1811-1, Copper and copper alloys Selection and preparation of samples for chemical analysis Part 1: Sampling of cast unwrought products ISO 1811-2, Copper and copper alloys Selection and preparation of sa
21、mples for chemical analysis Part 2: Sampling of wrought products and castings 3 Principle Dissolution of a test portion in a mixture of hydrochloric acid/hydrogen peroxide and nitric acid solutions followed, after suitable dilution, by aspiration into an air/acetylene flame of an atomic absorption s
22、pectrometer. Measurement of the absorption of the 223,1 nm line emitted by a bismuth hollow-cathode or electrodeless discharge lamp. 4 Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Hydrochloric acid, HCl ( =
23、 1,19 g/ml) 4.2 Nitric acid, HNO3( = 1,40 g/ml) 4.3 Hydrogen peroxide, H2O230 % (mass fraction) solution 4.4 Bismuth stock solution, 1,0 g/ l Bi Weigh (0,25 0,001) g of bismuth (Bi 99,999 9 %) and transfer it into a 250 ml beaker. Add 50 ml of nitric acid (4.2) and cover with a watch glass. Heat gen
24、tly until the bismuth is dissolved and then bring to the boiling point until the nitrous fumes have been expelled. Cool to room temperature and transfer the solution quantitatively into a 250 ml one-mark volumetric flask, dilute to the mark with water and mix well. 1 ml of this solution contains 1,0
25、 mg of Bi. 4.5 Bismuth standard solution, 0,1 g/l Bi Transfer 25,0 ml of the bismuth stock solution (4.4) into a 250 ml one-mark volumetric flask. Dilute to the mark with water and mix well. Prepare this solution immediately prior to use. 1 ml of this solution contains 0,1 mg of Bi. BS EN 14938-2:20
26、10EN 14938-2:2010 (E) 5 4.6 Copper base solution, 20 g/l Cu Into a 600 ml tall beaker weigh 10,0 g of bismuth-free copper (Bi 0,005 %). Add 50 ml of distilled water and, in small portions, 50 ml of nitric acid (4.2). Cover and heat gently until the copper is completely dissolved, then con-tinue heat
27、ing to the boiling point. Cool to room temperature. Wash the beaker cover and the sides of the beaker with water. Transfer the solution quantitatively into a 500 ml one-mark volumetric flask, dilute to the mark with water and mix well. 5 Apparatus 5.1 Atomic absorption spectrometer, fitted with an a
28、ir/acetylene burner. 5.2 Bismuth hollow-cathode or electrodeless discharge lamp. 6 Sampling Sampling shall be carried out in accordance with ISO 1811-1 or ISO 1811-2, as appropriate. Test samples shall be in the form of fine drillings, chips or millings with a maximum thickness of 0,5 mm. 7 Procedur
29、e 7.1 Preparation of the test portion solution 7.1.1 Test portion Weigh (1 0,001) g of the test sample. 7.1.2 Test portion solution Transfer the test portion (7.1.1) into a 250 ml beaker. Add 10 ml of distilled water, 0,5 ml of nitric acid (4.2), 0,5 ml of hydrogen peroxide (4.3) and 20 ml of hydroc
30、hloric acid (4.1). Cover with a watch glass and heat gently until the test portion is completely dissolved, then continue heating to the boiling point. Cool to room temperature. Wash the beaker cover and the sides of the beaker with water. Transfer the dissolved test portion into a 100 ml one-mark v
31、olumetric flask. Dilute to the mark with water and mix well. 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 omitting the test portion. 7.3 Check test Make a pre
32、liminary check of the apparatus by preparing a solution of a reference material or a synthetic sample containing a known amount of bismuth and of composition similar to the material to be analysed. Carry out the pro-cedure specified in 7.5. BS EN 14938-2:2010EN 14938-2:2010 (E) 6 7.4 Establishment o
33、f the calibration curve 7.4.1 Preparation of the calibration solutions 7.4.1.1 General In all cases, copper and chloride concentrations in the calibration solutions shall be similar to those of the test por-tion solutions. The presence of copper in the calibration solutions compensates for chemical
34、interaction effects of copper in the test solution. Normally no similar additions are required to compensate for the effect of alloying elements. If an al-loying element is present in the material to be analysed in mass fraction 10 %, an appropriate mass of this ele-ment shall be added to the calibr
35、ation solutions. The volumes of copper base solution added (4.6) have been cal-culated to compensate for chemical interaction effects of copper in test solutions of copper or high-copper alloys. Overcompensation may occur if the same volumes are added when the test samples are copper-based alloys wh
36、ere the percentage of copper is lower. In these cases the volumes of copper base solution shall be decreased to match the copper content of the test sample in solution. The bismuth concentration of the calibration solutions shall be adjusted to suit the sensitivity of the apparatus used, so that the
37、 curve of absorbance as a function of concentration is a straight line. NOTE The amount of HNO3in the sample solutions is different from that in the calibration solutions. This does not effect the measurement. 7.4.1.2 Bismuth mass fractions between 0,01 % and 0,05 % Into each of a series of five 100
38、 ml one-mark volumetric flasks, introduce 20,0 ml of hydrochloric acid (4.1) and the volumes of the bismuth standard solution (4.5) and of the copper base solution (4.6) shown in Table 1. Dilute to the mark with water and mix well. Table 1 Calibration for bismuth mass fractions between 0,01 % and 0,
39、05 % Bismuth Corresponding Corresponding Copper Corresponding Correspondingstandard bismuth bismuth base copper bismuthsolution volume mass concentration after solution volume mass mass fraction(4.5) final dilution (4.6) of sampleml mg mg/ml ml g % 0a0 0 50 1,000 0 1 0,10 0,001 0 50 1,000 0,010 2 0,
40、20 0,002 0 50 1,000 0,0203 0,30 0,003 0 50 1,000 0,030 5 0,50 0,005 0 50 1,000 0,050aBlank test on reagents for calibration curve. 7.4.1.3 Bismuth mass fractions between 0,050 % and 0,25 % Into each of a series of five 100 ml one-mark volumetric flasks, introduce 20,0 ml of hydrochloric acid (4.1) a
41、nd the volumes of the bismuth stock solution (4.4) and of the copper base solution (4.6) shown in Table 2. Dilute to the mark with water and mix well. BS EN 14938-2:2010EN 14938-2:2010 (E) 7 Table 2 Calibration for bismuth mass fractions between 0,05 % and 0,25 % Bismuth stock solution volume (4.4)
42、Corresponding bismuth mass Correspondingbismuth concentration after final dilution Copper base solution volume(4.6) Corresponding copper mass Correspondingbismuth mass fraction of sample ml mg mg/ml ml g % 0a0 0 50 1,00 0 0,5 0,50 0,005 50 1,00 0,050 1,0 1,00 0,010 50 1,00 0,101,5 1,50 0,015 50 1,00
43、 0,15 2,5 2,50 0,025 50 1,00 0,25aBlank test on reagents for calibration curve. 7.4.2 Adjustment of the atomic absorption spectrometer Fit the bismuth hollow-cathode or electrodeless discharge lamp (5.2) into the atomic absorption spectrometer (5.1), switch on the current and allow it to stabilize.
44、Adjust the wavelength in the region of 223,1 nm to minimum absorbance. Following the manufacturers instructions, fit the correct burner, light the flame and allow the burner temperature to stabilize. Taking careful note of the manufacturers instructions regarding the minimum flow rate of acetylene,
45、aspirate the calibration solution of highest concentration of analyte and adjust the burner configuration and gas flows to obtain maximum absorbance. 7.4.3 Spectrometric measurement of the calibration solutions Aspirate the relevant series of calibration solutions (see 7.4.1.2 or 7.4.1.3 depending o
46、n the expected bismuth content) in succession into the flame and measure the absorbance for each. Take care to keep the aspiration rate constant throughout the preparation of the calibration curve. Spray water through the burner after each measurement, see Note. NOTE For certain types of apparatus,
47、instead of water it is preferable to use a solution containing the attack reagents, in the same concentrations as in the test portion solutions. 7.4.4 Calibration curve Establish the calibration curve using measured absorbances and corresponding analyte amounts. Use appropriate spectrometer software
48、 or an off-line computer for regression calculations or prepare a graphical representation. 7.5 Determination 7.5.1 General The analyses shall be carried out independently, in duplicate. 7.5.2 Preliminary spectrometric measurement Carry out a preliminary measurement on the test portion solution (7.1
49、.2) following the procedure specified in 7.4.2 and 7.4.3 at the same time as the spectrometric measurements are carried out on the calibration solutions (see 7.4.1). Estimate the preliminary analyte amount by using the calibration curve (7.4.4). BS EN 14938-2:2010EN 14938-2:2010 (E) 8 7.5.3 Spectrometric measurements 7.5.3.1 Use of the calibration curve Repeat the measurements and determine the concentration directly using the appropriate calibration curve. 7.5.3.2 Use of bracketing method Carry
