Evaluation of specific high-performance liquid-chromatographic determinations of urinary adrenaline and noradrenaline by comparison with isotope dilution mass spectrometry.
A method for the determination of metadrenaline (MA), normetadrenaline (NMA) and 3-methoxytyramine (3-MT) in human urine using high-performance liquid chromatography followed by electrochemical detection (ECD) was validated primarily by comparing the results with those obtained by a gas chromatography-mass spectrometry (GC-MS) reference method. Correlation coefficients of 0.93, 0.94 and 0.91 were obtained for MA, NMA and 3-MT, respectively, in a group of healthy controls consisting of 30 women and 30 men. A systematic difference was detected only for 3-MT (-16%). Further tests of accuracy (linearity and recovery) and precision demonstrated that the described method must be considered to be a reliable approach to assess urinary metadrenalines in the diagnosis of phaeochromocytoma. At lower concentrations (MA, 248 nmol/L; NMA, 434 nmol/L; 3-MT, 402 nmol/L), within-assay coefficients of variation were close to 5% or less (5.3, 4.6 and 2.2%, respectively) and between-assay coefficients of variation were 8.9, 11.2 and 12.3%, respectively, for the same low levels. This raises the possibility that this method can also be applied to assess urinary free, unconjugated metanephrines. Sex differences were detected for MA and NMA excretion when expressed in nmol per 24 h and nmol/mmol creatinine, respectively, by both ECD and GC-MS methods.
Willemsen
J J
JJ
Department of Chemical Endocrinology, University Medical Centre Nijmegen, The Netherlands.
Ross
H A
HA
Wolthers
B G
BG
Sweep
C G
CG
Kema
I P
IP
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003404:Creatinine / Q000652:urine; D004298:Dopamine / Q000031:analogs & derivatives* / Q000652:urine; D004563:Electrochemistry / Q000379:methods; D004837:Epinephrine / Q000652:urine*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000652:urine*; D009647:Normetanephrine / Q000652:urine; D012016:Reference Values; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D009647:Normetanephrine; D003404:Creatinine; C001746:3-methoxytyramine; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine