BS EN 14662-5-2005 Ambient air quality - Standard method for measurement of benzene concentrations - Diffusive sampling followed by solvent desorption and gas chromatography《环境空气质量.pdf

1、BRITISH STANDARDBS EN 14662-5:2005Ambient air quality Standard method for measurement of benzene concentrations Part 5: Diffusive sampling followed by solvent desorption and gas chromatographyThe European Standard EN 14662-5:2005 has the status of a British StandardICS 13.040.20g49g50g3g38g50g51g60g

2、44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14662-5:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee

3、on 4 August 2005 BSI 4 August 2005ISBN 0 580 46134 3request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence

4、Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself co

5、nfer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 31 and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd.

6、 No. Date CommentsA list of organizations represented on this subcommittee can be obtained on present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European devel

7、opments and promulgate them in the UK.National forewordThis British Standard is the official English language version of EN 14662-5:2005. The UK participation in its preparation was entrusted by Technical Committee EH/2, Air quality, to Subcommittee EH/2/3, Ambient atmospheres, which has the respons

8、ibility to: aid enquirers to understand the text;EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14662-5May 2005ICS 13.040.20English versionAmbient air quality - Standard method for measurement ofbenzene concentrations - Part 5: Diffusive sampling followed bysolvent desorption and gas chromatograp

9、hyQualit de lair ambiant - Mthode pour le mesurage desconcentrations en benzne - Partie 5 : Echantillonnage pardiffusion suivi dune dsorption au solvant et dunechromatographie en phase gazeuseLuftbeschaffenheit - Standardverfahren zur Bestimmungvon Benzolkonzentrationen - Teil 5: Diffusionsprobenahm

10、emit anschlieender Lsemitteldesorption undGaschromatographieThis European Standard was approved by CEN on 21 March 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without

11、any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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

12、 translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece,

13、 Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de

14、 Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14662-5:2005: EEN 14662-5:2005 (E) 2 Contents Page Foreword 3 1 Scope .4 2 Normative References 4 3 Terms and definitions.4 4 Method description.6 4.1

15、 Principle.6 4.2 Reagents and Materials 7 4.3 Apparatus 9 4.4 Sampling10 4.5 Procedure 11 4.6 Calculations of mass concentration of benzene 12 4.7 Report 13 5 Determination of measurement uncertainty .13 5.1 Introduction.13 5.2 Parameters contributing to measurement uncertainty 14 6 Recommendations

16、for use .15 Annex A (informative) Suppliers of charcoal-based organic vapour diffusive samplers a.16 Annex B (informative) Specific information of sampler type A.17 Annex C (informative) Specific information of sampler type B.19 Annex D (informative) Assessment of performance indicators and uncertai

17、nty contributions.21 Annex E (informative) Performance characteristics 29 Bibliography.31 EN 14662-5:2005 (E) 3 Foreword This European Standard (EN 14662-5:2005) has been prepared by Technical Committee CEN/TC 264 “Air Quality”, the secretariat of which is held by DIN. This European Standard shall b

18、e given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2005, and conflicting national standards shall be withdrawn at the latest by November 2005. This document has been prepared under a mandate given to CEN by the European

19、Commission and the European Free Trade Association, and supports essential requirements of EU Directive 2000/69/EC and EU Directive 96/62 EC. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standa

20、rd: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14662-5:2005 (E) 4 1

21、Scope This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union for the determination of benzene in ambient air 1 for the purpose of comparison of measurement results with limit values with a one-year reference period. This part of EN 14662 gives

22、 general guidance for the sampling and analysis of benzene in air, by diffusive sampling, solvent desorption and capillary gas chromatography. This part of EN 14662 is valid for the measurement of benzene in a concentration range of approximately 0,5 g/m3to 50 g/m3in an air sample typically collecte

23、d over a period of several days or several weeks. A number of devices are recommended for the sampling of benzene, each device having a different range of applicability, particularly with regard to the optimum period of exposure. The upper limit of the useful range is set by the sorptive capacity of

24、 the activated charcoal and, subject to dilution of the analysed solution, by the linear dynamic range of the gas chromatograph column and detector or by the sample splitting capability of the analytical instrumentation used. The lower limit of the useful range depends on the noise level of the dete

25、ctor and on blank levels of benzene and/or interfering artefacts on the sampling devices or in the carbon disulphide. Alternative sorbents to activated charcoal may be used provided that the equivalence in performance characteristics of the procedure is demonstrated. Alternative desorption solvents

26、to carbon disulphide may be used provided that the equivalence in performance characteristics of the procedure is demonstrated. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For

27、undated references, the latest edition of the referenced document (including any amendments) applies. ENV 13005:1999, Guide to the expression of uncertainty in measurement EN 13528-2:2002, Ambient air quality - Diffusive samplers for the determination of concentrations of gases and vapours - Require

28、ments and test methods. Part 2: Specific requirements and test methods EN 13528-3:2003, Ambient air quality - Diffusive samplers for the determination of concentrations of gases and vapours Part 3: Guide for selection, use and maintenance EN ISO/IEC 17025:2000, General requirements for the competenc

29、e of testing and calibration laboratories (ISO/IEC 17025:1999) ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results - Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method ISO 5725-3:1995, Accuracy (trueness

30、and precision) of measurement methods and results - Part 3: Intermediate measures of the precision of a standard measurement method 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. EN 14662-5:2005 (E) 5 3.1 certified reference material A

31、reference material 3.7, accompanied by a certificate, one or more of whose property values are certified by a procedure which establishes its traceability to an accurate realisation of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncert

32、ainty at a stated level of confidence. ISO Guide 30:1992 3.2 combined standard uncertainty standard uncertainty of the result of a measurement when that result is obtained from the values of a number of other quantities, equal to the positive square root of a sum of terms, the terms being the varian

33、ces or covariances of these other quantities weighted according to how the measurement result varies with changes in these quantities ENV 13005:1999 3.3 desorption efficiency ratio of the mass of analyte desorbed from a sampling device to that applied EN 838:1995 3.4 Diffusive sampler a device which

34、 is capable of taking samples of gases or vapours from the atmosphere at a rate controlled by a physical process such as gaseous diffusion through a static air layer or a porous material and/or permeation through a membrane, but which does not involve the active movement of air through the device NO

35、TE 1 Active normally refers to the pumped movement of air. NOTE 2 This definition differs from that in EN 838:1995 by the addition of the words “or a porous material”. 3.5 Diffusive uptake rate rate at which the diffusive sampler collects a particular gas or vapour from the atmosphere, expressed in

36、picograms per parts per billion1 per minute (pg/ppb/min) or cubic centimetres per minute (cm3/min) NOTE 1 pg/ppb/min are equivalent to ng/ppm/min. NOTE 2 This definition differs from that in EN 838:1995 by the substitution of “picograms per parts per billion” for “nanograms per parts per million”. T

37、he expression is numerically the same, but ambient concentrations are usually in the ppb range. 3.6 expanded uncertainty quantity defining an interval about the result of a measurement that may be expected to encompass a large fraction of the distribution of values that could reasonably be attribute

38、d to the measurand ENV 13005:1999 NOTE 1 The fraction may be viewed as the coverage probability or level of confidence of the interval. NOTE 2 To associate a specific level of confidence with the interval defined by the expanded uncertainty requires explicit of implicit assumptions regarding the pro

39、bability distribution characterised by the measurement result and its combined 1ppb is volume fraction, ()=10-9; ppm is volume fraction, ()=10-6. EN 14662-5:2005 (E) 6 standard uncertainty. The level of confidence that can be attributed to the interval can be known only to the extent to which such a

40、ssumptions may be justified. NOTE 3 Expanded uncertainty is termed overall uncertainty in ENV 13005:1999. 3.7 reference material material or substance, one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessmen

41、t of a measurement method, or for assigning values to materials. ISO Guide 30:1992 3.8 repeatability conditions conditions where independent test results are obtained with the same method on identical test items in the same laboratory by the same operator using the same equipment within short interv

42、als of time ISO 3534-1:1993 3.9 standard uncertainty uncertainty of the result of a measurement expressed as a standard deviation ENV 13005:1999 3.10 uncertainty (of measurement) parameter, associated with the results of a measurement, that characterises the dispersion of values that could reasonabl

43、y be attributed to the measurand NOTE 1 The parameter may be, for example, a standard deviation (or given multiple of it), or the half width of an interval having a stated level of confidence. NOTE 2 Uncertainty of measurement comprises, in general, many components. Some of these components may be e

44、valuated from the statistical distribution of the results of a series of measurements and can be characterised by experimental standard deviations. The other components, which can also be characterised by standard deviations, are evaluated from assumed probability distributions based on experience o

45、r other information. NOTE 3 It is understood that the result of a measurement is the best estimate of the value of a measurand, and that all components of uncertainty, including those arising from systematic effects, such as components associated with corrections and reference standards, contribute

46、to this dispersion ENV 13005:1999. Attention is drawn to the fact that the terms Ambient Air and Limit Value are defined in Directive 96/62/EC 1. 4 Method description 4.1 Principle The diffusive sampler is exposed to air for a measured time period. The rate of sampling is determined by prior calibra

47、tion in a standard atmosphere (4.2.6) The benzene vapour migrates into the sampler by diffusion and is collected on the sorbent, normally activated carbon. The collected vapour is desorbed by a solvent, normally carbon disulphide, and the solution is analysed with a gas chromatograph equipped with a

48、 flame ionisation detector, mass spectrometer or other selective detector. The analysis is calibrated by means of vapour spiking onto a diffusive sampler or from calibration solutions of known amounts of benzene in carbon disulphide. Information on possible saturation of the sorbent, the effect of t

49、ransients and the effect of face velocity is given in EN 13528-3. This also explains the dependence of diffusion uptake rates on the concentration level of EN 14662-5:2005 (E) 7 pollutants and the time of diffusive sampling, for non-ideal sorbents, which results in different values being given in Annexes B and C. The theory of performance of diffusive samplers is also given in EN 13528-3. 4.2 Reagents and Materials During the analysis, use only reagents of known purity appropriate to the application. Use only volumetric glassware and s