Screening method for pesticides in air by gas chromatography/tandem mass spectrometry.

A multiresidue method for determining more than 70 pesticides in air has been validated using a single injection with gas chromatography/tandem mass spectrometry (GC/MS/MS). The method validation considered both stages of sampling and analysis. The sampling method, based on active sampling using sorption in sorbent cartidges, was validated by generating standard atmospheres. Performance parameters of the method were evaluated, with a reduction in the limits of quantification by injecting a higher volume of sample extract, and increase of selectivity by the use of MS/MS detection mode. The method was based on solid-phase extraction, which permits a degree of automation. The best adsorbents were found to be Chromosorb 106 and Tenax TA. The retention capacity of these sampling sorbents allows up to 1440L of air to be sampled without any breakthrough for most of the compounds. Data were generated for assessing the potential exposure of bystanders. The application of the method to the analysis of the air in urban locations near agricultural areas showed that pesticides were present in most of the samples. Copyright # 2004 John Wiley & Sons, Ltd. There are widespread concerns about human exposure to pesticides, principally for the acute and chronic exposures which may occur in a working environment. However, more recently, concerns have arisen over the long-term chronic exposure of bystanders, due to the transport of pesticides in the air from locations where they are applied in neighbouring urban areas. Inhalation is an important route of environmental exposure for bystanders living in the neighbourhood of agricultural areas. However, the extent of the problem increases if the transfer of pesticides from the air to the food chain is also considered. The structure of a bioaccumulation model is quite simple, and includes human exposure via food, air and water. Within the agricultural food chain consideration needs to be given to exposure of non-target crops, with the uptake of pesticides from soil and air to grass, and further transfer to grazing cattle, for example.