Psilocybin was quantitatively determined in methanolic extracts of dried fruiting-bodies of the basidiomycete Inocybe aeruginascens and its content was compared with that in Psilocybe bohemica and P. semilanceata. By menas of HPLC it was found that the content of psilocybin in Inocybe aeruginascens is lower than in Psilocybe species. Similarly to Psilocybe, the content of psilocybin in Inocybe decreased during storage of dried fruiting-bodies. The psilocybin content lalso depends on the origin of the fruiting-bodies. Atropine and scopolamine were assayed in leaf samples and cultured cells of Atropa belladonna L. by capillary gas chromatography. The samples were extracted and purified before the gas chromatographic analysis by passage through disposable extraction columns of reversed phase type. Deviation among the analyses was 4.0% for atropine and 2.9% for scopolamine at 50 mg/I. The limit of detection was 5 mg/I for both alkaloids