Determination of thiabendazole in fruits and vegetables by capillary electrophoresis

A capillary electrophoresis method was developed to quantify thiabendazole in various fruits and vegetables. Thiabendazole was extracted by adding 20 mL of methylene chloride to a 5 gram sample followed by homogenization and centrifugation. A 5 mL aliquot of the supernatant was removed and evaporated under nitrogen. The residue was reconstituted in 1 mL of HPLC grade water acidified with phosphoric acid (pH 3). Quantitation was performed using UV photodiode detection at 298 nm. Intra-assay and inter-assay reproducibility studies run at concentrations from 0.88 ppm to 20.88 ppm indicated the procedure was reproducible. A comparison was made between CE and HPLC for thiabendazole. The linear regression was y = 1.0927 x -0.3631 with a correlation coefficient of 0.91. The detection limit is 0.40 ppm.