HALLUCINOGENIC SPECIES IN AMANITA-MUSCARIA - DETERMINATION OF MUSCIMOL AND IBOTENIC ACID BY ION-INTERACTION HPLC

Ibotenic acid and muscimol are considered the principal components res ponsible of the hallucinogenic properties of Amanita muscaria. In this paper a sensitive ion-interaction HPLC method is presented which perm its the simultaneous determination of ibotenic acid and muscimol. A Cl s reverse phase is the stationary phase and the mobile phase is an aqu eous solution of 5.0 mM octylammonium o-phosphate. A spectrophotometri c comparative detection performed at 230 and 254 nm is employed. Detec tion limits are of 18 mu g/L for ibotenic acid and of 30 mu g/L for mu scimol. Different sample pretreatment processes were compared. The hig hest recovery yields together with the minimum matrix effect were obta ined by a procedure which only consists in the sonication of the fresh sample and its squeezing. The extract obtained is then diluted as req uired and filtered (0.2 mu m) before injection. This preparation offer s the further advantage to maximally preserve the native composition. The method was applied in the analysis of Amanita muscaria and permitt ed to evaluate the content of muscimol and ibotenic acid in heads and stems of the mushrooms. The same analysis performed for samples of Ama nita citrina confirmed the absence in this species of both ibotenic ac id and muscimol.