UHPLC Determination of Residual Amount of Thiram in Vegetables

A method for the determination of residual amount of thiram in vegetables by UHPLC was proposed. The sample was extracted with a mixed solution of methanol and H2O (40+60), and the extract was purified by dispersive solid phase extraction. The eluate obtained were separated on Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm), using a mixture of methanol and H2O (15+85) as mobile phase. PDA at the wavelength of 254 nm was adopted for the determination. Linear relationship between values of peak areas and mass concentration of thiram was kept in the range of 0.002 5-1.0 mg·L-1, with detection limit (3S/N) of 0.02 mg·kg-1. The proposed method was used in the analysis of samples of vegetables, i.e. cowpea, eggplant, tomato, and cucumber; and values of recovery found by standard addition method were in range of 73.3%-96.3% with RSD′s (n=6) in the range of 0.6%-6.2%.