Quantitation of urinary normetanephrine and metanephrine by reversed-phase extraction and mass-fragmentographic analysis.
Hydrolyzed urine with added ring-trideuterated normetanephrine and metanephrine is applied to wet C18-reversed-phase minicolumns. The "metanephrines" are eluted, dried, derivatized with pentafluoropropionic anhydride, and analyzed with the gas chromatograph-mass spectrometer. Ions for the nondeuterated and trideuterated compounds are monitored at ml z 458 and 461, respectively. For both normetanephrine and metanephrine, the standard curve is linear over the range 10-2000 micrograms/L and the procedure has adequate precision both within-run (CV less than 3%) and between-day (CV less than 7%). Alkaline pH in the extraction is important for optimal analytical recovery. We have examined the potential value of untimed urine specimens for screening purposes and compared 24-h urine concentrations of these analyses in normotensive and hypertensive persons.
D002853:Chromatography, Liquid; D004837:Epinephrine / Q000031:analogs & derivatives*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006973:Hypertension / Q000652:urine; D008676:Metanephrine / Q000652:urine*; D009647:Normetanephrine / Q000652:urine*; D010673:Pheochromocytoma / Q000652:urine; D012016:Reference Values
D009647:Normetanephrine; D008676:Metanephrine; D004837:Epinephrine