Antiepileptic Drugs: A Current Assessment of Simultaneous Determination of Multiple Drug Therapy By Gas Liquid Chromatography-On Column Methylation

Abstract

A revised GC procedure for antiepileptic drugs yields rapid clinical analyses. A new internal reference standard 5-ethyl-5-tolylbarbituric acid is included in the toluene reference solutions. The method involves extracting buffered serum with toluene containing either 2 or 3 internal reference standards. Antiepileptic drugs in the toluene extract are concentrated in 25 µl TMH, 2M in methanol, an aliquot of which is injected into the GC. Methylated derivatives formed on-column require 20 min or 60 min analysis time depending on drug therapy and choice of oven temperatures. The resolution of nine drugs is shown in this method.