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

The sampling and analysis of organic compounds in air remain a challen ge. Air is a matrix very difficult to handle. In addition, the polluta nts are usually present at very low concentrations; so, their detectio n and quantitation require a preconcentration step. This paper describ es 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 p rocedure is expensive and time-consuming. The adsorption of pollutants on adsorbents faces a growing interest, despite the difficulty to cho ose the appropriate support in order to obtain quantitative yields. To overcome this problem, two or three types of adsorbents may be used i n series for collecting a wide range of analytes. In addition, the min iaturization of these techniques (i.e. microtraps and solid-phase micr oextraction) is also very promising: easy to handle, low cost, no solv ent required, detection limits at the ppt level when sensitive detecto rs are used.