NEW METHOD FOR THE RAPID-DETERMINATION OF TRIAZINE HERBICIDES AND SOME OF THEIR MAIN METABOLITES IN WATER BY USING COUPLED-COLUMN LIQUID-CHROMATOGRAPHY AND LARGE-VOLUME INJECTION

Coupled-column liquid chromatography with ultraviolet detection was ap plied to the trace-level determination of simazine, atrazine, terbuthy lazine and terbutryn, as well as the main atrazine metabolites, deisop ropylatrazine, deethylatrazine and hydroxyatrazine, in environmental w ater samples rendering a very sensitive and rapid method which does no t require any preconcentration step of the water sample. A sample volu me of 2 ml, previously buffered with ammonium acetate for the determin ation of metabolites, was directly injected in the chromatographic sys tem using two reversed-phase C-18 coupled columns. Detection limits be tween 0.1 and 0.5 mu g l(-1) were directly reached for both the parent pesticides and the polar metabolites. All these compounds were succes sfully recovered from different environmental waters. Drinking and sur face water samples were spiked at different concentration levels (1-20 mu g l(-1)) yielding average recoveries between 86 and 104% (n=5) wit h coefficients of variation between 1 and 7%. If necessary, lower dete ction limits, between 0.02 and 0.1 mu g l(-1), were easily reached by preconcentration of 100 ml of water samples using SPE cartridges. Reco very experiments were performed on drinking water samples spiked at 0. 1 and 0.5 mu g l(-1) yielding average recoveries between 84 and 103% w ith coefficients of variation between 1 and 6%. (C) 1997 Elsevier Scie nce B.V.