Fluorescence detection and determination of patulin by thin-layer chromatography of its aniline imine

A sensitive and simple procedure is descrobed for the analysis of the mycotoxin patulin. The method involves extraction of patulin from the sample, silica gel column chromatographic clean-up, preparation of the aniline imine, thin-layer chromatographic separation on silica gel, hydrogen chloride hydrolysis of the imine, and fluorophore formation from the liberated aniline with fluorescamine. A linear calibration curve was obtained for the 10-100 ng range and the limit of detection was 5 ng. Recoveries of patulin from samples of apple juice spiked at 50-500 ppb were quantitative.