M/257 - Benzene in ambiant air

This European Standard specifies a semi-continuous measurement method for the determination of the concentration of benzene present in ambient air based on automated sampling and analysis by gas chromatography. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate automated gas chromatograph (GC) by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass con¬centration of benzene present in ambient air in the range up to 50 µg/m3 benzene. This concentration range represents the certification range for the type approval test.
Other ranges may be used depending on the levels present in ambient air.
NOTE 1   When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of benzene in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources.
The results are expressed in µg/m3 (at 20 °C and 101,3 kPa).
NOTE 2   50 µg/m3 of benzene corresponds to 15,4 nmol/mol of benzene.
This European Standard contains information for different groups of users.
Clauses 5 to 7 and Annexes C and D contain general information about the principles of benzene measurement by automated gas chromatography and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of benzene analysers. These sections contain information about:
-   type-approval test conditions, test procedures and test requirements;
-   analyser performance requirements;
-   evaluation of the type-approval test results;
-   evaluation of the uncertainty of the measurement results of the benzene analyser based on the type-approval test results.
Clauses 9 to 11 and Annex F are directed towards monitoring networks performing the practical measurements of benzene in ambient air. These sections contain information about:
-   initial installation of the analyser in the monitoring network and acceptance testing;
-   ongoing quality assurance/quality control;
-   calculation and reporting of measurement results;
-   evaluation of the uncertainty of measurement results under practical monitoring conditions.

This part of EN 14662 is in accordance with the generic methodology 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 general guidance for the sampling and analysis of benzene in air by pumped 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 µg/m3  to 50 mg/m3 in an air sample of 1 m3 volume, typically collected over a period of 24 hours.
The upper limit of the useful range is set by the sorptive capacity of the sorbent and 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 detector and on blank levels of benzene and/or interfering artefacts on the sorbent and in the desorption solvent.
The method described here is based on sampling on sample tubes typically containing 100 mg of activated charcoal and desorption using 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 to carbon disulphide may be used provided that the equivalence in performance characteristics of the procedure is demonstrated.

This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union reference method 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 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 mg/m3 to 50 mg/m3 in an air sample typically collected 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 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 detector 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 to carbon disulphide may be used provided that the equivalence in performance characteristics of the procedure is demonstrated.

This part of EN 14662 gives general guidance for the sampling and analysis of benzene in air by pumped sampling, thermal desorption and capillary gas chromatography.
This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union reference method 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 is valid for the measurement of benzene in a concentration range of approximately 0,5 mg/m3 to 50 mg/m3 in an air sample typically collected over a period of 24 hours.
The upper limit of the useful range is set by the sorptive capacity of the sorbent and by the linear dynamic range of the gas chromatograph column and detector or by the sample splitting capacity of the analytical instrumentation used. The lower limit of the useful range depends on the noise level of the detector and on blank levels of benzene  and/or interfering artefacts on the sorbent. Artefacts are typically sub ng for sorbents, but  higher levels of aromatic hydrocarbons have been noted in other sorbents. The detection limit will be approximately 1/10 of the lower concentration range.

This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union reference method 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 general guidance for the sampling and analysis of benzene in air by diffusive sampling, thermal 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 mg/m3 to 50 mg/m3 in an air sample typically collected over a period of 14 days.
The upper limit of the useful range is set by the sorptive capacity of the sorbent and 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 detector and on blank levels of benzene and/or interfering artefacts on the sorbent. Artefacts are typically sub ng for sorbents such as graphitised carbon, but higher levels of aromatic hydrocarbons have been noted in other sorbents.

This part of EN 14662 gives general guidance for the sampling and analysis of benzene in air by pumped sampling, thermal desorption and capillary gas chromatography.
This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union reference method 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 is valid for the measurement of benzene in a concentration range of approximately 0,5 mg/m3 to 50 mg/m3 in an air sample typically collected over a period of 24 hours.
The upper limit of the useful range is set by the sorptive capacity of the sorbent and by the linear dynamic range of the gas chromatograph column and detector or by the sample splitting capacity of the analytical instrumentation used. The lower limit of the useful range depends on the noise level of the detector and on blank levels of benzene  and/or interfering artefacts on the sorbent. Artefacts are typically sub ng for sorbents, but  higher levels of aromatic hydrocarbons have been noted in other sorbents. The detection limit will be approximately 1/10 of the lower concentration range.

This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union reference method 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 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 mg/m3 to 50 mg/m3 in an air sample typically collected 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 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 detector 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 to carbon disulphide may be used provided that the equivalence in performance characteristics of the procedure is demonstrated.

This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union reference method 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 general guidance for the sampling and analysis of benzene in air by diffusive sampling, thermal 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 mg/m3 to 50 mg/m3 in an air sample typically collected over a period of 14 days.
The upper limit of the useful range is set by the sorptive capacity of the sorbent and 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 detector and on blank levels of benzene and/or interfering artefacts on the sorbent. Artefacts are typically sub ng for sorbents such as graphitised carbon, but higher levels of aromatic hydrocarbons have been noted in other sorbents.

This part of EN 14662 is in accordance with the generic methodology 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 general guidance for the sampling and analysis of benzene in air by pumped 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 µg/m3  to 50 mg/m3 in an air sample of 1 m3 volume, typically collected over a period of 24 hours.
The upper limit of the useful range is set by the sorptive capacity of the sorbent and 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 detector and on blank levels of benzene and/or interfering artefacts on the sorbent and in the desorption solvent.
The method described here is based on sampling on sample tubes typically containing 100 mg of activated charcoal and desorption using 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 to carbon disulphide may be used provided that the equivalence in performance characteristics of the procedure is demonstrated.

This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union Reference Method 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.
The standard describes guidelines for measurements with, and type approval of, automated gas chromatographs. The use of automated instruments gives this part a different structure compared to the other parts including the procedure for selecting an appropriate automated gas chromatograph by means of type approval tests.
Requirements for use in the field are also described.
The standard is applicable to measurements of airborne benzene vapour in the concentration range from 0 µg/m3 to 50 µg/m3 (Standardised to 101,3 kPa and 293 K). This concentration range represents the certification range for benzene in the type approval test.

This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union Reference Method 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.
The standard describes guidelines for measurements with, and type approval of, automated gas chromatographs. The use of automated instruments gives this part a different structure compared to the other parts including the procedure for selecting an appropriate automated gas chromatograph by means of type approval tests.
Requirements for use in the field are also described.
The standard is applicable to measurements of airborne benzene vapour in the concentration range from 0 µg/m3 to 50 µg/m3 (Standardised to 101,3 kPa and 293 K). This concentration range represents the certification range for benzene in the type approval test.