Determination of 4-hydroxy-3-methoxyphenylethylene glycol 4-sulfate in human urine using liquid chromatography-tandem mass spectrometry.
A major metabolite of norepinephrine (NE) in brain is 4-hydroxy-3-methoxyphenylethylene glycol (MHPG). In many species, a large fraction of MHPG formed in brain is converted to the sulfate conjugate. Consequently, MHPG sulfate has been proposed as a biomarker for NE metabolism in the central nervous system. As part of the clinical trials of the monoamine oxidase inhibitor selegiline for treating cocaine addiction, we required a method for measuring urine concentrations of MHPG sulfate. Using a deuterium-labeled analogue as an internal standard, we developed a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/ MS) method for determination of MHPG sulfate in human urine. Sample preparation involves simply diluting 50 microL of urine with 1 mL of ammonium formate buffer and adding the internal standard. The sample is centrifuged, the supernate is transferred to an autosampler vial, and 10 microL is injected into the LC-MS/MS system. Standard curves from 50 to 10,000 ng/mL are generated. Only one sample of 277 clinical samples analyzed had a concentration outside of this range. Precision (coefficient of variation) ranged from 1.9 to 9.7%, and accuracy ranged from 97 to 103% of expected values for controls prepared by spiking sulfatase-treated urine with MHPG sulfate.
Jacob
Peyton
P
Division of Clinical Pharmacology, San Francisco General Hospital Medical Center, University of California, 94110, USA. peyton@itsa.ucsf.edu
Wilson
Margaret
M
Yu
Lisa
L
Mendelson
John
J
Jones
Reese T
RT
D001192:Arylsulfatases / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D007553:Isotope Labeling; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000652:urine*; D012015:Reference Standards; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization
D007202:Indicators and Reagents; C030284:3-methoxy-4-hydroxyphenylglycol sulfate; D008734:Methoxyhydroxyphenylglycol; D001192:Arylsulfatases