BS 1747-13-1994 Methods for measurement of air pollution - Determination of the particulate lead content of aerosols collected on filters atomic absorption spectrometric method《空气污.pdf

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1、BRITISH STANDARD BS1747-13: 1994 ISO9855:1993 Methods for Measurement of air pollution Part 13: Determination of the particulate lead content of aerosols collected on filters: atomic absorption spectrometric method UDC 614.71:543.42:546.815BS1747-13:1994 This British Standard, having been prepared u

2、nder the directionof the Environment andPollution Standards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 15 February1994 BSI10-1999 The following BSI references relate to the work on this standard: Committee reference EPC/35 Draft for comment91/56

3、613 DC ISBN 0 580 22905 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Environment and Pollution Standards Policy Committee (EPC/-) to Technical Committee EPC/35, upon which the following bodies were represented: Association of Consul

4、ting Scientists BCIRA British Cement Association British Coal Corporation British Gas plc Combustion Engineering Association Department of Health Department of the Environment (Her Majestys Inspectorate of Pollution) Department of Trade and Industry (Laboratory of the Government Chemist) Department

5、of Trade and Industry (Warren Spring Laboratory) Engineering Equipment and Materials Users Association European Resin Manufacturers Association GAMBICA (BEAMA Ltd.) Health and Safety Executive Institute of Petroleum Institution of Environmental Health Officers Institution of Gas Engineers National S

6、ociety for Clean Air Royal Society of Chemistry The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Asbestosis Research Council British Steel plc Department of Trade and Industry (National Physical Laboratory) Fibre Cement Manufacturers Assoc

7、iation Institute of Energy Lead Development Association Amendments issued since publication Amd. No. Date CommentsBS1747-13:1994 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative references 1 3 Principle 1 4 Reagents 1 5 Apparatus 1 6 Sa

8、mpling 1 7 Procedure 2 8 Expression of results 3 9 Performance of methods 3 10 Interferences 3 11 Test report 3 Annex A (normative) Filter digestion by reflux with nitric acid and hydrochloric acid 4 Annex B (normative) Filter digestion with nitric acid and hydrogen peroxide 4 Annex C (normative) Fi

9、lter digestion under pressure with nitric acid 5 List of references Inside back coverBS1747-13:1994 ii BSI 10-1999 National foreword This Part of BS1747, which has been prepared under the direction of the Environment and Pollution Standards Policy Committee, is identical with ISO9855:1993 Ambient ai

10、r Determination of the particulate lead content of aerosols collected on filters Atomic absorption spectrometric method, published by the International Organization for Standardization (ISO) with the active participation and approval of the UK. This Part of BS1747 is one of a series relating to air

11、quality arising from UK participation in the work of ISO/TC146. Methods for the determination of particular constituents of ambient air will be published as further Parts of this British Standard. Topics relating to air quality characteristics will be published as Parts of BS6069 Characterization of

12、 air quality. The Technical Committee has reviewed the provisions of ISO648:1977, ISO6879:1983 and ISO6955:1982, to which normative reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. NOTETypographical error. InB.2, line1, “on” should be

13、 “of”. 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 British Standard does not of itself confer immunity from legal obligations. Cross-references International Sta

14、ndard Corresponding British Standard ISO1042:1983 BS1792:1982 Specification for one-mark volumetric flasks (Identical) ISO4793:1980 BS1752:1983 Specification for laboratory sintered or fritted filters including porosity grading (Identical) Summary of pages This document comprises a front cover, an i

15、nside front cover, pagesi andii, pages1 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS1747-13:1994 BSI 10-1999 1 1 Scope This Internat

16、ional Standard specifies a method based on acid digestion and atomic absorption spectrometry for the chemical analysis of lead samples collected on filters from ambient air. The method is applicable to ambient air samples with particulate lead contents, such that the amount of deposited particulate

17、lead collected on the filter of the sampling equipment is greater than14g if the final determination is made by flame atomic absorption spectrometry. Final determination by graphite furnace atomic absorption spectrometry allows measurement of quantities of less than14g, but is only applicable after

18、experimental validation of detection limits. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revi

19、sion, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO648:1977, Laboratory glas

20、sware One-mark pipettes. ISO1042:1983, Laboratory glassware One-mark volumetric flasks. ISO4793:1980, Laboratory sintered (fritted) filters Porosity grading, classification and designation. ISO6879:1983, Air quality Performance characteristics and related concepts for air quality measuring methods.

21、ISO6955:1982, Analytical spectroscopic methods Flame emission, atomic absorption, and atomic fluorescence Vocabulary. 3 Principle Particulate material collected on a filter is digested with acid. Any lead present is solubilized and the sample solution analysed by atomic absorption spectrometry. 4 Re

22、agents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity (as in4.1). It is essential that the lead contents of reagents are constant so that reproducible blank values can be obtained. 4.1 Distilled or deionized water, with a

23、lead content less than0,014g/ml and an electrical conductivity less than0,2mS/m(24S/cm), or an electrical resistivity greater than5k7m. 4.2 Nitric acid (HNO 3 ), concentrated, 20 =1,42g/ml, redistilled with a lead content less than0,014g/ml. 4.3 Nitric acid, dilute, approximately0,1mol/l. Add10ml of

24、 concentrated nitric acid(4.2) to500ml of water(4.1) and dilute to1litre with water(4.1). 4.4 Lead standard solution, corresponding to10004g of Pb per millilitre. Use commercial standard solutions at a concentration of10004g/ml, or prepare a lead standard solution as follows. Dissolve1,598g 0,001g o

25、fleadnitrate Pb(NO 3 ) 2 previously dried to constant mass at110 C and cooled in a desiccator, in dilute nitric acid(4.3). Quantitatively transfer the solution to a1000ml one-mark volumetric flask(5.1.2) and make up to the mark with dilute nitric acid(4.3). 5 Apparatus Ordinary laboratory apparatus

26、and 5.1 Glassware, borosilicate. NOTE 1It is preferable to reserve a set of glassware for the determination of lead by this method, to ensure that problems do not arise from incomplete removal of contamination. 5.1.1 One-mark pipettes, complying with ISO648. 5.1.2 One-mark volumetric flasks, of capa

27、cities from10ml to1000ml, complying with ISO1042. 5.2 Atomic absorption spectrometer, set up and operated according to the manufacturers instructions and equipped with: a burner for use with an air/acetylene flame and/or a graphite furnace with auto-injection, a lead hollow cathode lamp or an electr

28、odeless discharge lamp, and a capability for correction of non-specific attenuation (see ISO6955) by using a deuterium lamp or Zeeman or Smith-Hieftje background correction systems. 5.3 Sampling equipment. Filters for analysis shall be of a membrane or glass-fibre type. Unexposed filters shall have

29、a maximum lead content considerably lower than the minimum quantity measurable by the atomic absorption procedure used. 6 Sampling The sampling time shall be sufficient for the amount of lead collected to be large enough for quantitative analysis.BS1747-13:1994 2 BSI 10-1999 7 Procedure 7.1 Cleaning

30、 of glassware 7.1.1 Before use, soak all glassware for24h in a mild detergent solution to remove any residual grease or chemicals. 7.1.2 After the initial cleaning(7.1.1), clean all glassware other than pipettes(5.1.1) and volumetric flasks(5.1.2) with hot concentrated nitric acid(4.2) and thoroughl

31、y rinse with water(4.1). 7.1.3 After the initial cleaning(7.1.1), clean the pipettes(5.1.1) and volumetric flasks(5.1.2) by soaking in dilute nitric acid(4.3) for several days, and then finally rinse with water(4.1). Clean glassware which has been through the whole cleaning procedure, and which has

32、been reserved for analysis of lead by this method, by rinsing thoroughly with dilute nitric acid(4.3) and then with water(4.1). 7.2 Calibration 7.2.1 Preparation of calibration solutions Prepare a calibration blank solution and at least five calibration solutions to cover the range of expected conce

33、ntrations of the test solutions, within the linear operating range of the atomic absorption spectrometer(5.2), by dilution of the lead standard solution(4.4). These calibration solutions shall be prepared so that they contain acid concentrations equivalent to those in the final sample solutions obta

34、ined using the chosen digestion method (see7.3.2). 7.2.2 Spectrometric measurements Set up the atomic absorption spectrometer(5.2) according to the manufacturers instructions, and optimize the setting of parameters including lamp current and monochromator slit width. For flame atomic absorption spec

35、trometry, optimize burner height, fuel and oxidant flow rates and nebulizer flow rate. For graphite furnace atomic absorption spectrometry, establish the optimum temperature programme to avoid losses of lead, especially during the ashing phase of the temperature programme. Do not use graphite furnac

36、e atomic absorption spectrometry without auto-injection. In all cases, correction for non-specific attenuation shall be used. 7.2.3 Plotting the calibration curve Prepare a calibration graph by plotting the absorbance of each calibration solution with respect to the absorbance of the calibration bla

37、nk solution, versus the concentration of lead in the calibration solutions, in micrograms per millilitre (or, if graphite furnace atomic absorption spectrometry is used, in micrograms per litre). 7.3 Determination 7.3.1 Blank filter Analyse at least one unexposed filter with each batch of exposed te

38、st filters. 7.3.2 Acid digestion of filters Carry out the digestion of sample and blank filters using one of the methods specified in Annex A to Annex C. The method specified in Annex A (digestion with nitric acid and hydrochloric acid) is the reference method. Use the method specified in Annex B (d

39、igestion with nitric acid and hydrogen peroxide) or the method specified in Annex C (digestion with nitric acid under pressure) only after demonstrating that these methods achieve complete analytical recovery. NOTE 2This demonstration should be based on measuring the recoveries obtained by using the

40、 method specified in Annex B or Annex C on equivalent samples to those being analysed, and then comparing the results with those obtained using the reference method specified in Annex A. The reference method should always be used where incomplete recovery is indicated by measurements or visual evide

41、nce of undissolved residues. 7.3.3 Spectrometric measurement Determine the concentration of lead in the sample solutions(7.3.2) using either flame or graphite furnace atomic absorption spectrometry, by measuring the absorbance at a wavelength of217,0nm or283,3nm, with correction for non-specific att

42、enuation. The sample concentration is related to the absorbance, and can be determined from the appropriate calibration graph(7.2.3). Use only the linear part of the calibration curve and dilute the test solutions whose response falls outside this region with an appropriate volume of dilute nitric a

43、cid(4.3). Record the dilution factor used. For the graphite furnace procedure, use the same final sampling volume for both analysis and calibration. 7.3.4 Blank solutions Analyse all of the blank solutions(7.3.1), and subtract the mean lead concentration of the blank solutions from the lead concentr

44、ation of the sample solutions. Where sample solutions are diluted into the linear operating range of the atomic absorption spectrometer, an equivalent dilution shall be made of the blank solutions; and the mean lead concentration of this diluted blank solution subtracted from the lead content of the

45、 diluted sample solutions. Use standardized statistical methods (see ISO6879) to determine the detection, limit, based on the standard deviation of the lead concentration in a minimum of six solutions obtained by dissolution of blank filters.BS1747-13:1994 BSI 10-1999 3 8 Expression of results Expre

46、ss the mass concentration of lead Pb , in micrograms per cubic metre, in the air sample to the nearest0,14g/m 3 , using the equation 9 Performance of methods The application of this International Standard to blank membrane and glass-fibre filters has demonstrated that a detection limit of14g is achi

47、evable using either of the three specified digestion methods. When the digestion method specified in Annex A (the reference method) was applied to filters spiked with an urban particulate reference material, the recovery of lead relative to the certified value was99,2% 4,3% for the spiked membrane f

48、ilters and101,0% 6,0% for the spiked glass-fibre filters. 10 Interferences The method may not be suitable for samples with high ratios between an interfering element and lead. The nature and extent of interferences depends on whether flame or graphite furnace atomic absorption spectrometry is used.

49、The only major spectral interference which is likely to occur is due to antimony when a wavelength of217,0nm is used. Where high concentrations of sodium are present in sample solutions, efficient correction of non-specific background absorbance is essential. 11 Test report The test report shall include at least the following information: a) all details necessary for the complete identification of the air sample, including details of the type of sampling equipment used; b) a reference to this International Standard; c) which sample digestion method