High-performance liquid chromatographic method for the determination of moniliformin in corn

A high-performance liquid chromatographic method using UV absorption was developed for determining moniliformin in corn. The toxin was extracted with water containing 1% tetrabutylammonium hydrogen sulfate (w/v). Paired moniliformin was partitioned into dichloromethane, which was evaporated to dryness at 50 degrees C. The residue was dissolved in water and applied to a disposable strong-anion exchange solid-phase extraction tube. Adsorbed moniliformin was eluted from the tube with 0.05M sodium dihydrogen phosphate monohydrate (pH 5). It was determined by ion-pair reversed-phase chromatography and UV measurement at 229 nm. The minimum detectable amount of pure moniliformin was 0.25 ng/injection (signal-to-noise ratio = 3:1). The detector response was linear from 0.25 to at least 20 ng. The limit of determination was 0.025 microgram/g corn. Recoveries of moniliformin from corn spiked at 0.025, 0.05, 0.25, and 1.0 microgram/g averaged 96.5, 96.2, 97.2, and 97.8% respectively.