HPLC Determination of Residual Carbamate Pesticides in Fruits and Vegetables with On-line Post-column Derivatization and Fluorescence Detection

Six residual carbamate pesticides in fruits and vegetables were determined by HPLC with on-line post-column derivatization and fluorescence detection.The sample was pounded,homogenized and extracted with acetonitrile,and purified by SPE column.The mixed solvent of methanol and dichloromethane(1+99) was used as eluant,and the eluates were collected and evaporated to dryness by N2-blowing.The residue was taken up with methanol and used for HPLC analysis.The Carbamate Analysis column (3.9 mm×150 mm,5 μm) was used as stationary phase and mixtures of methanol and H2O with various ratios were used as mobile phase in gradient elution.On-line post-column derivatization was carried out in the reactor into which 0.05 mol·L-1 NaOH solution and derivatizing agent,OPA solution were introduced at a flow-rate of 0.5 mL·min-1.Fluorescence detection was made at wavelengths of 339 nm (λex) and 445 nm (λem).Ranges of linearity for the 6 pesticides were found between 0.01-2.5 mg·L-1,with detection limits (3S/N) in the range of 0.5-3.0 μg·kg-1.Results of recovery test obtained were in the range of 86.4%-103.0%.