A sensitive method for gas-chromatographic assay of barbiturates in body fluids.

The Authors present a gas-chromatographic method which allows for the rapid identification and assay of barbiturates and antiepileptics in body fluids. The Kupferberger procedure for extraction is used. The identification is obtained on two different columns: 10% Dexil 300 GC on Chromosorb W-HP and 3% OV 17 on Chromosorb G AW-DMCS (80-100 mesh). A considerable and interesting reduction of the barbiturates adsorption in the columns is obtained by preliminary conditioning with tetraethylorthosilicate. In this way, phenobarbital and cyclobarbital may also be assayed up to 1 microgram/ml in blood. For the simultaneous assay of therapeutic levels of phenobarbital and hydrantoins methylderivates are better employed: blood concentrations as low as 0.1 microgram/ml are easily detected.