[A simple method for determining antiepileptic preparations in biological fluids by using high-pressure liquid chromatography (HPLC)].

The authors suggest a simple HPLC method with ultraviolet detection at 200 nm for finding barbiturates, diphenine, etosuccimide, and carbamazepin in plasma and saline using an original technology of liquid-liquid extraction. It allows clear chromatograms with a minimal amount of interfering compounds, a high extraction percentage (90-100%) and sufficient sensitivity to be obtained. A method has also been worked out for detecting clonazepam on the basis of solid-phase extraction (cartridge "Diapak-C16") precolumn concentration, and ultraviolet detection at 200 and 215 nm. The suggested extraction technologies also make possible successful monitoring of antiepileptics in the saline, for which the plasma/saline coefficients are calculated and the dependence between the degree of phenobarbital extraction into the saline and its pH is demonstrated.