Cilësia e ajrit të mjedisit – Metoda standarde për matjen e përqëndrimeve të benzenit – Pjesa 2 : Marrja e mostrës me pompim e pasuar me desorbim në tretës dhe gazkromatografi.

Ambient air quality - Standard method for measurement of benzene concentrations - Part 2 : Pumped sampling followed by solvent desorption and gas chromatography

Asnjë informacion i shtuar.

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.