OCCURRENCE OF PESTICIDES IN DANISH SHALLOW GROUND-WATER

Shallow ground water from four different catchment areas, two sandy an d two clayey locations, were investigated for content of pesticides an d -degradation products. The samples were taken from screens in extrac tion wells placed from 1.5 to 5 meters below surface. 46 different com pounds were included in the study, and the analysis were performed wit h liquid chromatography mass spectrometry (LC-MS) with detection limit s below 0.01 mu g/L. In total more than 300 samples were analysed and the most frequently found compounds being atrazine and its degradation products, bentazone, MCPA, metamitron, isoproturon and simazine. 23 o ut of the 46 compounds were detected in one or more samples. Four diff erent sulfonylurea herbicides were included in the study as they to so me extent have substituted phenoxyacid herbicides in agricultural prac tice and in much lower dosage. Sulfonylurea herbicides did not occur i n any samples. (C) 1998 Elsevier Science Ltd. All rights reserved.