TRACE ENRICHMENT METHODS FOR THE DETERMINATION OF ORGANIC POLLUTANTS IN AMBIENT AIR

The sampling and analysis of organic compounds in air remain a challenge. Air is a matrix very difficult to handle. In addition, the pollutants are usually present at very low concentrations; so, their detection and quantitation require a preconcentration step. This paper describes the enrichment methods that may be used for the accurate monitoring of pollutants in ambient air. Many techniques can be used to collect air samples. The simplest way is to use special containers, but this procedure is expensive and time-consuming. The adsorption of pollutants on adsorbents faces a growing interest, despite the difficulty to choose the appropriate support in order to obtain quantitative yields. To overcome this problem, two or three types of adsorbents may be used in series for collecting a wide range of analytes. In addition, the miniaturization of these techniques (i.e. microtraps and solid-phase microextraction) is also very promising: easy to handle, low cost, no solvent required, detection limits at the ppt level when sensitive detectors are used.