Determination of Thiabendazole Residues in Pears by Solid-Phase Spectrofluorimetry

Abstract

Abstract An analytical procedure for determination of thiabendazole (TBZ) residues in pears is described. The method involves extracting the chemical from the chopped fruit with buffer solution (acetic acid–acetate, pH 4.6), use of Sephadex G-15 dextrantype gel as a solid support, and determination of TBZ by solid-phase spectrof luorimetry (SPF). The relative fluorescence intensity of the Sephadex G- 15 gel–TBZ system, packed in a 1 mm-thickness silica cell, was measured directly at λex = 303 nm and λem = 350 nm with a solid-phase attachment. The applicable concentration range was 5.0–20.0 ppb with a detection limit of 0.5 ppb. Recoveries were from 98.7 to 102.0% when 15.0 ppb of TBZ was added to the fruit.