Mildiomycin Residue Analysis by Ion-Pair Reversed-Phase High Performance Liquid Chromatography with Fluorometric Detection

Abstract

A microanalytical method of mildiomycin for residue analysis in cucumber fruits, tobacco leaves and soil was developed. Mildiomycin in cucumber fruits and tobacco leaves was extracted with water and cleaned up by CM-Sephadex column chromatography. Mildiomycin in soil was hardly extracted with water, but sufficiently with saturated sodium pyrophosphate solution. The extract was desalted and cleaned up by CG-50 column chromatography. Mildiomycin reacted at pH 8.0 with fluorescamine, a reagent for the fluorometric quantitation of primary amine, and was determined by ion-pair reversed-phase high performance liquid chromatography with fluorometric detection. The limits of detection in cucumber fruits, tobacco leaves and soil were 0.06ppm, 0.2ppm and 0.7ppm respectively. The recoveries of mildiomycin from cucumber fruits, tobacco leaves and soil at respective fortification levels of 1.2, 3 and 10ppm were over 70%.