Simple and rapid gas chromatographic determination of valproic acid in plasma

Abstract

A specific and sensitive gas chromatographic method for monitoring valproic acid in plasma is described. The procedure involves a single solvent extraction of the drug from acidified plasma into chloroform containing cyclohexanecarboxylic acid as an internal standard. The extract is subsequently analysed on a gas chromatograph equipped with a flame ionisation detector. The extraction efficiency of the assay was 97.4±0.37% and the limit of detection was found to be 7 µg ml^–1.