This study aimed at developing and validating a method for the simultaneous determination of triazines (ametryne, atrazine, prometryne and terbuthylazine), triazinones (metribuzin and hexazinone) and a triazole (flutriafol) in water by ultrasound vortex assisted dispersive liquid-liquid microextraction (USVADLLME) and GC-MS. The experimental conditions that provided the best results were: 5.00 mL of sample, 100 mL of extractor solvent (toluene), vortex agitation for 30 s and sonication for 1 min. at 240 W and 40 ºC. The USVADLLME provided recoveries ranging from 77.2% to 109%, with a repetitivity and intermediate precision varying from 1.4 to 9.0% and 2.9 to 15%, respectively. The method detection limits ranged between 0.10 and 2.71 µg L-1. The method was applied to different surface water samples and a matrix effect was not observed. Once validated, the proposed method was applied to ten water samples of an important agricultural region of Mato Grosso State/Brazil, but none of the studied analytes were detected. The USVADLLME is proposed as an efficient, fast, simple and non-expensive alternative technique for the simultaneous determination of multiclass pesticides in water.
Keywords:
method validation; herbicides; gas chromatography
