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

Abstract

Coupled-column liquid chromatography with ultraviolet detection was applied to the trace-level determination of simazine, atrazine, terbuthylazine and terbutryn, as well as the main atrazine metabolites, deisopropylatrazine, deethylatrazine and hydroxyatrazine, in environmental water samples rendering a very sensitive and rapid method which does not require any preconcentration step of the water sample. A sample volume of 2 ml, previously buffered with ammonium acetate for the determination of metabolites, was directly injected in the chromatographic system using two reversed-phase C 18 coupled columns. Detection limits between 0.1 and 0.5 μg l −1 were directly reached for both the parent pesticides and the polar metabolites. All these compounds were successfully recovered from different environmental waters. Drinking and surface water samples were spiked at different concentration levels (1–20 μg l −1) yielding average recoveries between 86 and 104% ( n = 5) with coefficients of variation between 1 and 7%. If necessary, lower detection limits, between 0.02 and 0.1 μg l −1, were easily reached by preconcentration of 100 ml of water samples using SPE cartridges. Recovery experiments were performed on drinking water samples spiked at 0.1 and 0.5 μg l −1 yielding average recoveries between 84 and 103% with coefficients of variation between 1 and 6%.