• 1 January 1981
    • journal article
    • research article
    • Vol. 3  (1) , 103-106
Abstract
A single high-recovery extraction process is described for rapid GLC determination of [the antiepileptic] valproic acid (VPA). The drug is extracted from acidified plasma into an equal volume (0.2 ml) of chloroform. Evaporation is avoided by extraction into a chloroform bed, from which an aliquot is analyzed by isothermal GLC employing a column packed with 10% DEGS. The reproducibility and accuracy of the method were good. In 100 plasma samples from patients, there was an excellent correlation (r = 0.98) between VPA levels determined concomitantly by this method and the technique of Kupferberg. Single plasma samples can be analyzed in 20 min, and 40 samples can easily be analyzed daily by a single technician. Ethosuximide concentrations can also be determined simultaneously. The method is suitable for emergency and routine use in drug monitoring laboratories.