HPLC Determination of Residual Amounts of Carbendazim,Thiabendazole,Thiophanate-methyl and Thiophanate in Orange

HPLC was applied to the determination of residual amounts of carbendazim,thiabendazole,thiophanate-methyl and thiophanate in orange.The sample was extracted with acetonitrile and the extract was purified on Carb/NH2 SPE column.The eluate was separated by gradient elution with methanol-water mixed solutions of different ratio on ZORBAX Extend-C18 (150 mm×4.6 mm,5 μm) column,and determined with UV detection at the wavelength of 267 nm.Linear relationship between values of peak areas and mass concentrations of the 4 pesticides were obtained in the range of 0.1-10.0 mg·L-1,with their detection limits (3S/N) of 0.05 mg·kg-1.The values of average recovery of four pesticides found were in the range from 75.0% to 98.7%,with RSD′s (n=7) in the range of 3.2%-14.3%.