Determination of metanephrines in plasma by liquid chromatography with electrochemical detection.

摘要: Metanephrines are O-methylated metabolites of catecholamines. We report the use liquid chromatography with electrochemical detection to determine plasma concentrations normetanephrine (NMN) and metanephrine (MN). Plasma NMN MN in 32 normal volunteers inpatients were compared 23 patients pheochromocytoma. adsorbed from onto a cation-exchange column eluted ammoniacal methanol. The dried residue was dissolved mobile phase injected reversed-phase column. Recoveries 1 mL averaged 50-70%, results varied linearly quantity over range 0.13-55 pmol. limit 25 fmol for 50 MN. Intra-assay CVs < 5%. In inpatients, ranged between 0.12 0.73 nmol/L (mean 0.38 nmol/L), 0.06 0.63 0.19 nmol/L). increased all pheochromocytoma (range 1-172 whereas 0.10-382 nmol/L) only 9 patients. assay method is reliable sensitive offers an approach examine extraneuronal metabolism may also be useful diagnosis