High pressure liquid chromatographic determination of imazalil residues in citrus fruit.

A high pressure reverse phase liquid chromatographic method is described for determining the fungicide imazalil (1-[2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl]-1H-imidazole) residues in whole citrus fruit, peel, and pulp. Imazalil is extracted from the fruit with ethyl acetate, partitioned into acid and back into ethyl acetate for cleanup, and detected by ultraviolet absorbance at 202 nm. Recovery from whole ground fruit of known amounts of imazalil applied to the surface of intact fruit averaged 84% 24 hr after application and 80% after the fruit had been stored 4 weeks at 15 degrees C.