Quantitation of 3'-hydroxypentobarbital in serum using high-performance liquid chromatography

A quantitative method for the determination of 3'-hydroxypentobarbital (3'HP) in serum has been developed using reversed-phase high-performance liquid chromatography. A sensitivity limit of 0.5 micrograms/ml in 100 microliters serum was obtained by detection at 215 nm. Serum concentrations of 3'HP were measured in patients receiving high-dose pentobarbital therapy and pentobarbital:3'HP concentrations are discussed.