[A simple gas chromatographic method for the determination of barbiturates in serum (author's transl)]

A simple gas chromatographic method for the determination of commercially available barbiturates used as hypnotics is presented. Saturated ammonium sulfate is added to the serum sample. The mixture is extracted three times with chloroform. The organic layer is dried over sodium sulfate and evaporated. The residue is dissolved in ethyl acetate/acetic acid (100 ml + 1 ml) and an aliquot is injected into the gas chromatograph. The precision in the series is between 3.0 and 7.2%; the recovery--with the exception of propallylonal--between 91 and 108%; the detection limit from 1.7 to 6.9 mumol/l. The specificity of the method was checked by comparing 1) the results obtained before and after additional purification of the extract by thin-layer chromatography, and 2) the retention times of about 100 drugs in the gas chromatographic systems that are used.