Enzymic digestion of biosamples as a method of sample pretreatment before XAD-2 extraction.

Four proteolytic enzymes trypsin, protease type I, protease type V (Pronase AS) and protease type VIII (Subtilisin) were used for digestion of blood, brain, liver, and kidney in experimental poisonings of dogs with phenobarbital, amitriptyline, diazepam, and chlorpromazine. Enzymic digestion was used also in 21 forensic cases of fatal poisonings with hypnotic and psychotropic drugs. Each enzyme applied gave a similar yield. The efficienct of enzymic digestion varied according to the kind of drug, tissue, and individual. In general, enzymic hydrolysis proved useful in isolation of psychotropic drugs from liver and brain, being less effective in the case of blood. The mechanism of drugs liberation after enzymic treatment remains obscure.