Determination of diuron, terbuthylazine, and terbutryn in wastewater and soil by micellar liquid chromatography

An analytical method for the quantification of the herbicides and algaecides diuron, terbuthylazine, and terbutryn in wastewater and soil by micellar liquid chromatography was developed. The sample preparation was expedited to reduce the number of intermediate steps and the use of chemicals. The analytes in soils were recovered by ultrasonication in the mobile phase. The obtained supernatant and the water samples were directly injected, thus avoiding intermediate steps. The chromatographic behavior of the analytes, depending on the surfactant and alcohol was studied, in order to optimize the chromatographic run, by a chemometrical approach. The herbicides were resolved in <16 min using a C18 column and a mobile phase of 0.07 M sodium dodecyl sulfate/6% 1-pentanol phosphate buffered at pH 3, running under isocratic mode at 1 mL/min. The detection absorbance wavelength was set to 240 nm. The method was successfully validated in terms of selectivity, detection limit (0.06 mg/L in water and 0.3 mg/kg in soil), quantitation range (0.2-2 mg/L in water and 1-10 mg/kg in soil), trueness (-6.1 to +5.0%), precision (<9.4%), and ruggedness (<8.3%). The procedure was reliable, practical, easy-to-handle, available, short-time and ecofriendly and useful for routine analysis. Its applicability to real samples was evaluated by analyzing several wastewater, decorative reservoir, and soil samples from agricultural and urban sources.