title: Isotope dilution ammonia chemical ionization mass fragmentographic analysis of urinary 3-O-methylated catecholamine metabolites. Rapid sample clean-up by derivatization and extraction of lyophilized samples.
abstract: We developed a method for simultaneous quantification of the urinary 3-O-methylated catecholamine metabolites 3-methoxytyramine, normetanephrine and metanephrine by stable isotope-dilution ammonia chemical ionization mass fragmentography. Prepurification of lyophilized samples was done by simultaneous deconjugation and pentafluoropropionylation, followed by extraction and rederivatization. Compared with our previously described method, based on acid hydrolysis, alkaline extraction, derivatization and electron-impact mass fragmentography, the present method was found to be less laborious, more sensitive and presumably more accurate. New urinary excretion values were established for apparently healthy adults. The present prepurification method may prove applicable for profiling of a variety of naturally occurring mono-, di- and polyamines in biological samples.
authors.affiliation: Central Laboratory for Clinical Chemistry, University Hospital of Groningen, Netherlands.
authors.forename: I P
authors.initials: IP
authors.lastname: Kema
authors.forename: G
authors.initials: G
authors.lastname: Meiborg
authors.forename: G T
authors.initials: GT
authors.lastname: Nagel
authors.forename: G J
authors.initials: GJ
authors.lastname: Stob
authors.forename: F A
authors.initials: FA
authors.lastname: Muskiet
mesh_terms: D000328:Adult; D000641:Ammonia / Q000737:chemistry; D004298:Dopamine / Q000031:analogs & derivatives* / Q000652:urine; D005612:Freeze Drying; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007554:Isotopes; D008676:Metanephrine / Q000652:urine*; D008875:Middle Aged; D009647:Normetanephrine / Q000652:urine*; D015203:Reproducibility of Results
chemical_list: D007554:Isotopes; D009647:Normetanephrine; D008676:Metanephrine; D000641:Ammonia; C001746:3-methoxytyramine; D004298:Dopamine