Determination by the radioactive indicator method of the retention and stability of thiabendazole in treated Valencia oranges

Abstract

Thiabendazole residues were determined by the radioactive indicator method in peel and pulp of oranges which had been dipped in a 0.1% aqueous suspension of the fungicidal agent thiabendazole, and then stored for periods up to four weeks. Whole peel from these oranges retained an average of ≃46 μg of thiabendazole/g after four weeks of storage. Inner peel contained only 8–21% of these levels, suggesting a slow inward diffusion of drug. The edible portion was virtually free of thiabendazole. Practically all of the applied agent was still present as intact thiabendazole after four weeks of storage.