HPLC-MS/MS Determination of Residual Amount of Bensultap in Vegetables

HPLC-MS/MS was applied to the determination of residual amount of bensultap in vegetables. Homogenized pulp (10.00 g) of the sample was taken and extracted thrice with CH₃CN (20 mL each). The combined extract was evaporated to about 5 mL. The solution was then purified by passing through TPT SPE column. The eluate (main) was reserved. The SPE column was rinsed with 25 mL of a mixture of CH₃CN and toluene (3+1). The eluate was combined with the main eluate, and evaporated first to about 5 mL at 45℃ in a water bath and then to dryness by N₂-blowing at 35℃ in the water bath. The residue was taken up and made up to 10 mL with a mixture of formic acid-CH₃CN (0.1+99.9). The solution was then analyzed by HPLC-MS/MS under the condition described. Linear relationship between values of peak area and mass concentration of bensultap was kept in the range of 1-500 μg·L^-1, with detection limit (3S/N) of bensultap in different matrixes in the range of 0.1-0.4 μg·kg^-1. On the base of blank sample, test for recovery was made by standard addition method. Values of recovery found were in the range of 48.0%-97.7%, with RSD's (n=6) in the range of 1.8%-12%.