Rapid Identification and Quantitative Determination of Barbiturates and Glutethimide in Blood by Gas—Liquid Chromatography

Abstract

Abstract Barbiturates and glutethimide can be identified and measured in whole blood, plasma, or serum in 20 min. An internal standard containing known amounts of five common barbiturates is added to the sample, the sample is acidified, and the sedatives are extracted rapidly into toluene, then from the toluene into a small volume of aqueous tetraethylammonium hydroxide. An aliquot of this last extract is introduced directly into the gas chromatograph, where the barbiturates are converted to their ethyl derivatives and separated on a silicone column. They are identified by observing which of the internal standard peaks has increased and measured by measuring the extent of increase. Glutethimide can be determined on the same chromatogram. Mephobarbital and phenobarbital can be simultaneously determined.