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.