Clinical Chemistry, Vol 17, 587-591, Copyright © 1971 by the American Association for Clinical Chemistry

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

¹ Medical Research Laboratories, Veterans Administration Hospital, 3200 Vine St., Cincinnati, Ohio 45220, and the Departments of Biological Chemistry and Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio. 45219.

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.