A modification of imazalil residue analysis in treated grapefruit

Residues of imazalil, 1-[2-(2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl]-1H-imidazole, a fungicide that prevents decay of citrus, were determined in treated grapefruit. The method consists of a simplified heptance-isoamyl extraction solvent, acid-base clean-up, and direct gas chromatographic analysis with electron-capture detection.