Direct determination of 4-hydroxy-3-methoxyphenylacetic (homovanillic) acid in urine by high-performance liquid chromatography with amperometric detection.

The improvement of high-performance liquid chromatographic analysis with electrochemical detection for urinary homovanillic acid is described. The method permits the chromatographic resolution of authentic homovanillic acid from coeluting interfering compounds in human and nonhuman primate, and rat urine. The electrochemically derived results are compared with post-column derivatized fluorescence results, and quality-control checks necessary to maintain assay precision in automated analysis are described.