Simultaneous liquid chromatographic determination of thiabendazole, o-phenylphenol, and diphenyl residues in citrus fruits, without prior cleanup.

A simple, rapid, efficient method has been developed for determining thiabendazole, o-phenylphenol, and diphenyl in citrus fruits by using high performance liquid chromatography, with fluorescence or ultraviolet detection. The compounds are extracted with ethyl acetate and separated from soluble fruit components on a LiChrosorb RP-8 column. Recovery of these compounds added to citrus fruits at 5 or 50 ppm levels was greater than 93%; the limit of detection for the compounds is 1 ppm.