[Isolation of blood caffeine as a model substance by enzymatic hydrolysis].

Organic solvent extraction of toxic compounds from blood either directly or following precipitation of serum proteins yields only free fractions. It is proposed to dissociate toxin-protein complexes in blood samples by enzymatic hydrolysis. Model caffeine complexes in an albumin solution were treated by tripsin, chemotripsin, and papain. The best results were obtained using chemotripsin and papain with which 70.4 +/- 1.6% and 62.2 +/- 1.2% of the caffeine was isolated from blood compared with 45.6% by direct extraction. Validation characteristics of the proposed method are specified.