Simultaneous analysis of homovanillic acid, 5-hydroxyindoleacetic acid, 3-methoxy-4-hydroxyphenylethylene glycol and vanilmandelic acid in plasma from alcoholics by high-performance liquid chromatography with electrochemical detection. Critical comparison of solid-phase and liquid-liquid extraction methods.

A method is described for the simultaneous determination of vanilmandelic acid, 3-methoxy-4-hydroxyphenylethylene glycol, 5-hydroxyindoleacetic acid, and homovanillic acid in a human plasma sample using reversed-phase high-performance liquid chromatography with column switching and amperometric detection. Two methods of sample preparation were tested. Liquid-liquid extraction yields better recoveries, is more selective and precise than solid-phase extraction and allows a shorter time of chromatographic analysis. Estimated plasma values of the metabolites from healthy controls are in good agreement with previously reported levels. Studies of alcoholics at the beginning of the delirium tremens provided different plasma levels of the metabolites, dependent on the different duration--and hence the severity--of the delirium.