Development of a gas chromatography–mass spectrometry method for the determination of pesticides in gaseous and particulate phases in the atmosphere

A reliable multi-residue method for determining gaseous and particulate phase pesticides in atmospheric samples has been developed. This method, based on full scan gas chromatography–mass spectrometry (GC–MS), allowed the proper determination of sixteen relevant pesticides, in a wide range of concentrations and without the influence of interferences. The pesticides were benfluralin, bitertanol, buprofezin, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, ethalfluralin, fenthion, lindane, malathion, methidathion, propachlor, propanil, pyriproxifen, tebuconazol and trifluralin. Comparisons of two types of sampling filters (quartz and glass fibre) and four types of solid-phase cartridges (XAD-2, XAD-4, Florisil and Orbo-49P) showed that the most suitable supports were glass fibre filter for particulate pesticides and XAD-2 and XAD-4 cartridges for gaseous pesticides (>95% recovery). Evaluations of elution solvents for ultrasonic-assisted extraction demonstrated that isooctane is better than ethylacetate, dichloromethane, methanol or a mixture of acetone:hexane (1:1).Recovery assays and the standard addition method were performed to validate the proposed methodology. Moreover, large simulator chamber experiments allowed the best study of the gas-particle partitioning of pesticides for testing the sampling efficiency for the validation of an analytical multiresidue method for pesticides in air. Satisfactory analytical parameters were obtained, with a repeatability of 5 ± 1%, a reproducibility of 13 ± 3% and detection limits of 0.05–0.18 pg m−3 for the particulate phase and 26–88 pg m−3 for the gaseous phase. Finally, the methodology was successfully applied to rural and agricultural samples in the Mediterranean area.

Figure optionsDownload as PowerPoint slideHighlights
► An efficient method for the determination of sixteen pesticides in atmospheric samples.
► XAD-4 is an interesting support for collecting gas-phase pesticides, with similar performances than the conventional XAD-2.
► The ultrasonic extraction is cheaper, less aggressive and time-consuming with excellent analytical parameters.
► The method has been successfully tested by using high volume atmospheric simulation chamber and field campaigns.