DETERMINATION OF PESTICIDES IN ENVIRONMENTAL WATERS BY AUTOMATED ONLINE TRACE-ENRICHMENT AND LIQUID-CHROMATOGRAPHY

Automated on-line trace-enrichment, liquid chromatographic analysis an d UV diode-array detection (DAD) were investigated for the determinati on of pesticides at the 0.1 mu g/l level in drinking and surface water s. The selection of the preconcentration parameters (sorbent, sample v olume, reproducibility) is discussed. Conditions are specified for qua ntification methods such as using calibration graphs constructed with spiked samples, standard addition methods and a calculation method inc luded in the DAD software depending on the sample nature. Detection li mits of 0.1 mu g/l were obtained using 150 ml of river waters without any clean-up.