Beschreibung:
<jats:p> Blood samples from patients on long-term sodium valproate (Epilim) therapy were analysed for valproic acid by two procedures, enzyme immunoassay (EMIT)* and gas-liquid chromatography (GLC). A critical evaluation of the effects of anticoagulants added to specimens was performed in addition to studies on reagent specificity, accuracy, and precision. </jats:p><jats:p> EMIT valproic acid reagent showed high specificity, and there was a good correlation between results obtained by EMIT and GLC over a wide range of concentrations. The accuracy and precision of EMIT assay was good over the therapeutic range of valproic acid. The presence of the anticoagulant EDTA or of fluoride/oxalate produced a bias towards high results for valproic acid as compared with those obtained from the analysis of serum. </jats:p>