Determination of penicillic acid and patulin by gas-liquid chromatography with an electron-capture detector.

Quantitative and concurrent determinations of penicillic acid and patulin have been achieved after separation of these compounds, as their trimethylsilyl derivatives, by gas-liquid chromatography with electron-capture detection and a column of 10% of DC-200 plus 15% of QF-1 on Gas-Chrom Q; the minimum determinable amounts of penicillic acid and patulin were 0.05 and 0.1 ng, respectively. The procedure devised for determining these compounds in grain involves extraction with solvents, followed by further clean-up by thin-layer chromatography; the detection limit of this procedure is about 0.02 ppm, and recovery at the level of 0.05 ppm is about 90%. The significant separation of penicillic acid and patulin produced in moldy rice is demonstrated on the gas chromatograms, and this makes possible a micro-assay for these toxic compounds in contaminated grain.