Enantioselective determination of triazole fungicide tebuconazole in vegetables, fruits, soil and water by chiral liquid chromatography/tandem mass spectrometry.

A novel and sensitive method was developed for the determination of tebuconazole enantioselectively using reversed-phase LC-MS/MS. The separation and determination were performed using on an amylose-based chiral stationary phase, a Lux 3u Amylose-2 column (150 mm×2.0 mm), under isocratic conditions at 0.3 mL/min flow rate. A series of chiral stationary phases were investigated and the effect of mobile phase composition on the enantioseparation was discussed. Parameters including the matrix effect, linearity, precision, accuracy and stability were evaluated. Under optimal conditions, the overall mean recoveries for two enantiomers from the soil, tomato, cucumber, pear and apple samples were 79.3-101.1% with 2.8-11.5% intra-day relative standard deviations (RSDs) and 4.1-8.6% inter-day RSDs at 5, 25 and 50 μg/kg levels; the mean enantiomer recoveries from the water samples were 89.6-101.9% with 3.3-10.2% intra-day RSDs and 5.1-7.7% inter-day RSDs at 0.25, 0.5 and 2.5 μg/kg levels. The limits of detection (LODs) for all enantiomers in tomato, cucumber, pear, apple, soil and water were less than 0.6 μg/kg, whereas the limit of quantification (LOQ) did not exceed 2.0 μg/kg. The results indicate that this proposed method is convenient and reliable for the enantioselective determination of tebuconazole enantiomers in foods and environment samples.