DETERMINATION OF THIABENDAZOLE RESIDUES IN WATERS BY SOLID-PHASE SPECTROFLUOROMETRY

A new, sensitive and simple spectrofluorometric method for the determi nation of thiabendazole (TBZ) residues was studied. TBZ on Sephadex G- 15 gel, pH 4.70 acetate buffer, is fixed to give fluorescence. The flu orescence of the gel-TBZ system, packed in a 1-mm quartz cell was meas ured directly using a solid-surface attachment. The applicable concent ration range was 1.5-10.0 ng.mL-1 with a relative standard deviation o f 1.4 % and a detection limit of 0.1 ng.mL-1. The method was applied t o the determination of thiabendazole in natural, waste, sea, and resid ual waters (98-100 % recovery). The method is more sensitive and selec tive than other methods described in the literature. The presence of o ther fluorescent pesticides (dichlone, carbaryl, morestan, o-phenylphe nol) with similar spectral features (lambda(exc) and lambda(em) neighb oring to excitation and emission wavelengths of the TBZ) did not cause interference.