[Photodensitometric determination of "PR-toxin", metabolite of Penicillium roqueforti (author's transl)].

Two methods are proposed for the determination of PR-toxin. One allows a direct quantitative estimation of the mycotoxin, the other utilizes an imine formation after reaction with ammonium hydroxide. In both cases a fluorodensitometric assay on thin-layer chromatographic plates is carried out after spraying with p-dimethylaminobenzaldehyde reagent. The two procedures can be applied to estimate the toxin in foodstuffs at levels as low as 10 and 1 microgram/kg, respectively.