DETERMINATION OF THIABENDAZOLE RESIDUES IN WHITE AND SWEET-POTATOES BY LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

A liquid chromatographic (LC) method was developed for determination o f thiabendazole (TBZ) residues in or on whole, unwashed white potatoes (Solanum tuberosum) and sweet potatoes (Ipomoea batatas), TBZ is extr acted from the potato homogenate with ethyl acetate and the extract pu rified and concentrated on a cation-exchange, solid-phase extraction c olumn, The extract is analyzed for TBZ residues by column LC with a ca tion-exchange column and fluorescence detection. Recoveries of TBZ fro m whole white potatoes fortified with TBZ at 0.05-20 ppm and from whol e sweet potatoes fortified with TBZ at 0.005-0.1 ppm averaged 100 and 94%, respectively, The method is also applicable for quantitation of T BZ residues in white potato waste (dried peel) used as an animal feed additive, The present method for monitoring TBZ residues in white and sweet potatoes and white potato waste (dried peel) is simple, rapid, a nd sensitive.