Preconcentration, thermal desorption & analysis of volatile organic compounds
Résumé
Volatile organic compounds ("VOC") cover a large number of compounds, of which some are toxic (benzène, 1,3-butadiene...) and others are involved in atmospheric chemistry, such as the so-called "ozone precursors". Both benzène and ozone precursors are now covered by European daughter directives. VOC represent a complex mixture and are present in ambient air at low concentrations: from tens of ppbv to sub-ppbv concentration levels. Therefore, their measurement requires preconcentration and high resolution separation. The precise sampling and measurement technique depends on the kind of compounds to be measured. However thé principle of the measurement remains the same and can be presented as in Figure 1. Solvent extraction of samples taken on activated carbon will not be covered by this paper, as this procedure is less sensitive and the solvents used are harmful to the environment.
Domaines
Sciences de l'environnement
Origine : Fichiers produits par l'(les) auteur(s)