Liquid chromatographic method for the determination of 3,4-dihydroxyphenylethylene glycol and 3,4-dihydroxymandelic acid in plasma.

A method is described for the simultaneous determination of the deaminated catecholamine metabolites 3,4-dihydroxyphenylethylene glycol (DOPEG) and 3,4-dihydroxymandelic acid (DOMA) in plasma by liquid chromatography with amperometric detection. The compounds are extracted from plasma by adsorption on alumina, then separated on a reversed-phase column coated with tributyl phosphate as the stationary liquid phase. It is a simple and selective method that permits the determination of basal levels of DOPEG and DOMA in plasma with a relative standard deviation of 3%.