Abstract
An optimized HPLC method for the analysis of selected pesticides (Atrazine, Diuron, Dichloran, Methiocarb, Folpet, Triazophos, Vinclozolin, Tetradifon and Carbophenothion) is developed by applying a solvent elution programme with two steps, isocratic and gradient mode, both in reverse phase (RP). In the isocratic step, the mobile phase is optimized by a grid search procedure over an water-acetonitrile-methanol solvent triangle. Off-line solid-phase extraction (SPE) has been combined with HPLC using a photodiode array detector (DAD) to isolate, recover and quantify the selected pesticides from water samples at ppb levels. The recoveries are higher than 75% in all cases except for atrazine in sea water (50%) and ground water (64%). 1,5–7.7% and most polar pesticide, Atrazine was only recovered between 50% (sea water) to 85% (drinking water) with CV of 8.3 and 5.0% respectively (Table 2).