Trace-level determination of triazines and several degradation products in environmental waters by disk solid-phase extraction and micellar electrokinetic chromatography

An analytical method combining disk solid-phase extraction with micellar electrokinetic chromatography has been developed for the determination of atrazine, simazine, hydroxyatrazine, deisopropylatrazine, deethylatrazine, propazine and prometryn in water samples. The influence of the buffer and sodium dodecyl sulfate (SDS) concentration, pH and organic modifier on the separation has been studied. Baseline separation of the seven triazines was achieved under the following conditions: 10 mM borate buffer, 60 mM SDS, 20% methanol and pH 9.2. C18-bonded silica and poly(styrene–divinylbenzene) (PS–DVB) disks were evaluated for solid-phase extraction of the selected pesticides (1 l of water sample). Using two PS–DVB disks, quantitative recoveries were obtained for all pesticides tested. The method was successfully applied for the determination of the seven triazines in drinking and well water at the 0.1 μg l−1 and 0.5 μg l−1 concentration levels, respectively. The detection limits for these analytes using the proposed analytical method were within the 0.02–0.06 μg l−1 range in drinking water and the 0.06–0.30 μg l−1 range in well water.