Determination of free 3-methoxy-4-hydroxyphenylglycol with several other monoamine metabolites in plasma by high-performance liquid chromatography with amperometric detection.

A reversed-phase liquid chromatographic method with amperometric detection has been developed for determining free 3-methoxy-4-hydroxyphenylglycol in plasma. The method is based on a simple and rapid extraction procedure employing a small C18 column. Vanillyl alcohol was used as an internal standard to obtain a good reproducibility. The 3-methoxy-4-hydroxyphenylglycol concentrations measured with the present method were in reasonable agreement with recently published data using high-performance liquid chromatography with amperometric detection and gas chromatography with mass spectrometry. The additional advantage of the present assay is that it can be performed in parallel with the quantification of other monoamine metabolites in plasma.