A novel and simple supported ionic-liquid-based solid-phase extraction method for the determination of triazine herbicides in rice was developed. Glass slides were functionalized by an ionic liquid, 1-carboxyethyl-3-methylimidazolium chloride, and were used for the simultaneous extraction of seven triazine herbicides in rice samples. The effects of the type of extraction solvent, the extraction time, the type and volume of loading solvent, and the type of eluting solvent on the extraction efficiency were investigated and optimized. Under the optimum operation conditions, the limits of detection for seven triazine herbicides in rice samples obtained by high-performance liquid chromatography were 3.16-5.42 ng/g, which were lower than the maximum residue levels established by various organizations. The linear correlation coefficients were higher than 0.9975 in the concentration range of 0.015-1.08 μg/g for the seven triazine herbicides. The recoveries of the seven triazine herbicides at the two concentration levels of 0.15 and 0.45 μg/g are between 82.47 and 104.21%, with relative standard deviations of 0.69-9.19%. The intra- and inter-day (n = 5) precisions for all triazine herbicides at the spiked level of 0.30 μg/g were 1.72-11.71%.
Keywords: High-performance liquid chromatography; Ionic liquids; Solid-phase extraction; Triazine herbicides.
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