Pesticides in ground water beneath Loukkos perimeter, Northwest Morocco

This study assesses pesticide occurrence in the ground water beneath the Loukkos area (Northwest Morocco). The inhabitants and farmers depend on ground water supplies for drinking water, crop irrigation and other uses. The plain provides ideal conditions for agriculture and thus the use of pesticides was increasing during the past decade. The 23 investigated pesticides belong to the endosulfan isomers and their degradation products, the triazines and the phenyl-ureas. The analyses were done using chromatographic techniques and solid-phase extraction. The analytical determination was optimized by selecting the best clean-up procedure to reach the highest pesticide recovery rate. So, clean-up with Florisil was applied for endosulfan and its metabolites. For the triazines and phenyl-ureas clean-up with LiChrolut EN was used. Endosulfan isomers and their degradation products both were detected in ground water samples of which the latter presents the highest concentrations. No herbicides (triazines and phenyl-ureas) were detected, what can be explained by the low use of these compounds in the area. With the exception of endosulfan ether, the results did not exceed the current drinking water quality established by the European Union.