Trace determination of triazine herbicides by means of coupled-column liquid chromatography and large volume injection

Abstract

Coupled-column liquid chromatography (LC-LC) with ultraviolet detection was used for the trace-level determination of simazine, atrazine, terbuthylazine and terbutryn in environmental water samples. A sample volume of 2 ml was directly injected in the Chromatographic system, using two reversed-phase C 18 coupled columns. The mobile phases consisted of two mixtures CH 3CN/H 2O, one with 40% of acetonitrile (M-1) and one with 70% (M-2). As a result, a rapid procedure with detection limits down to 0.1 μg 1 −1 was developed. The method was validated by means of recovery experiments. Drinking and surface water samples were spiked at 4 and 0.4 μg 1 −1 yielding average recoveries between 86–104% ( n = 5) with coefficients of variation between 1–6%. The overall procedure allowed a sample throughput of up to 60 samples per day. Surface water samples from a wet area of Castellón (Spain) were analyzed by means of the proposed LC-LC procedure, thus simazine, terbuthylazine and terbutryn were detected at sub-μg 1 −1 levels. Lower detection limits, between 0.02–0.05 μg 1 1, were reached by preconcentration of 100 ml of water samples on C 18 bonded phase solid phase extraction (SPE) cartridges. Drinking water samples spiked at 0.1 μg 1 −1 were preconcentrated and analyzed by LC-LC yielding average recoveries between 84–103% ( n = 3) with coefficients of variation between 2–5%.