Determination of catecholamines and their metabolites in human plasma using liquid chromatography with coulometric multi-electrode cell-design detection

A solid-phase extraction method (SPE) combined with liquid chromatography with coulometric multi-electrode detection for the analysis of the main endogenous catecholamines and its metabolites in plasma samples has been developed. For this purpose, the influence of various parameters on chromatography performance, such as the pH and composition of the mobile phase, and the potentials of oxidation and reduction process, was investigated. The SPE procedure developed, following catecholamine complexation with diphenylborate, enables yields for all analytes limits of detection of 0.01-0.05 ng l(-1) lower than their plasma levels. The recovery of the compounds averaged 61-99%. Relative standard deviation values for repeatability were less than 3%. This novel and rapid method can be employed in a routine clinical setting. (C) 2001 Elsevier Science B.V. All rights reserved.