Determination of Acidic Pesticides in the Drinking Water of Greece Using Capillary Gas Chromatography-Mass Spectrometry

There is no data currently available on acidic pesticides in the drinking water of Greece, although considerable quantities of them are in use. In this study, the occurrence of the six most important acidic herbicides in the drinking water of Greece was investigated. The target compounds studied include four chlorophenoxy herbicides, namely mecoprop, dichlorprop, MCPA and 2,4-D, and two other acidic herbicides, i.e. bromoxynil and bentazone. Analysis was carried out at a concentration level of 100 ng L−1 using capillary gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM). The method involved a pre-concentration with solid phase extraction and derivatization with pentafluorobenzyl bromide. Thirty-eight samples of drinking water from nine regions in Greece were screened. No herbicides were detected although fortification experiments with parallel water samples resulted in recovery rates better than 70%. The detection limits of the recovered compounds were found to be between 10 and 50 ng L−1.