Hydrolysis of carbon-labeled cocaine in human serum

Hydrolysis of 14C-cocaine in human serum, separation of the metabolites on TLC, and subsequent identification on GLC is described. AT 1 H, 20 percent of the cocaine was metabolized to benzoylecgonine, ecgonine and ecgonine methylester. At this time interval the highest percent of product was in the form of the ecogonine methyl ester, a metabolite not previously reported in humans. After 4 h, 67 percent of the cocaine was hydrolyzed; of this, 45 percent was benzoylecgonine and ecgonine in a ratio of 1.6 to 1. The half-life for cocaine hydrolyzed in human serum was approximately 2.5 h.