Monitoring water-polluting pesticides in Hungary

A 5-year survey of pesticide active ingredients and residues in Hungarian surface water samples was carried out within the framework of a national monitoring program. Based on physicochemical and ecotoxicological properties of currently registered pesticide active ingredients, a range of analytes was selected to cover compounds that potentially contaminate surface waters due to their solubility properties or mode of use. Target analytes thus included acetochlor, atrazine, carbofuran, diazinon, fenoxycarb, metribuzin, phorate, prometryn, terbutryn, and trifluralin. During the sampling campaign these pesticides were monitored in Hungarian surface waters including streams, rivers and lakes. Samples were obtained annually in two runs: before and after pesticide sprayings in spring and early summer. Samples were prepared for analysis by solid-phase extraction and solid-phase microextraction. Target analytes were monitored by gas chromatography - mass spectrometry, using electron impact and chemical ionization techniques. Spatial distribution monitoring of the surface water pollutants indicated two heavily contaminated point sources, as well as a wide range of non-point contamination. One or more pesticide active ingredients above the detection limit of the instrumental method used were measured in 209 samples, giving the result that 59% of the samples collected during the sampling campaign contained pesticide residues.