A method for determination of subpicomole concentrations of tetrahydropapaveroline in rat brain by high-performance liquid chromatography with electrochemical detection

A sensitive and selective method for detection of tetrahydropapaveroline (THP) in rat brain has been developed. The procedure employs a multiple-stage separation scheme that selectively isolates THP from rat brain tissue and utilizes the sensitivity and resolution of reversed-phase high-performance liquid chromatography with electrochemical detection to provide an analysis with high specificity for THP. The mean (±SD) recovery of THP from rat brain homogenates, fortified at levels ranging from 0.25 to 3.0 pmol per whole brain, was 43.4 ± 3.5%. The concentration of THP in brains of rats pretreated with l-dopa was 0.44 ± 0.14 (SD) pmol per gram. The limit of detection of THP was approximately 0.1 pmol (0.03 ng) per gram brain.