Using Chemical Derivatization to Determine the Human Urinary Acidic Catecholamine Metabolites Quantitatively by Liquid Chromatography/Electrospray Ionization‐Tandem Mass Spectrometry

Abstract

AbstractBased on a 4,6‐dimethoxy‐2‐(methylsulfonyl)pyrimidine (DMMSP) labeling reagent, a sensitive method to determine acidic catecholamine metabolites homovanillic acid (HVA), vanillymandelic acid (VMA), 3,4‐dihydroxymandelic acid (DOMA) and 3,4‐dihydroxyphenylacetic acid (DOPAC) has been developed using simple chemical derivatization with liquid chromatography/electrospray ionization‐tandem mass spectrometry (LC/ESI‐MS/MS). Acidic catecholamine metabolites were converted to stable 4,6‐dimethoxypyrimidinyl (DMP) derivatives by one‐step derivatization. Because of bulky DMP group(s) introduced into the structures of these metabolites, subsequent analysis by LC/ESI‐MS/MS in positive ionization with multiple reaction monitoring (MRM) allowed specific detection of DMP derivatives of these metabolites with a wide linear relationship range. The limits of detection were in the range of 1–5 ng/mL. The mean recoveries determined were 100.2% –104.4%. Both relative standard deviation and error for intra‐ and inter‐day measurements were less than 10% for acidic catecholamine metabolites. This strategy enabled accurate and specific determination of acidic catecholamine metabolites in human urine.