Determination of urinary 5-hydroxytryptophol glucuronide by liquid chromatography-mass spectrometry.
5-Hydroxytryptophol glucuronide (GTOL) is the major excretion form of 5-hydroxytryptophol (5-HTOL), a minor serotonin metabolite under normal conditions. Because the concentration of 5-HTOL is markedly increased following consumption of alcohol, measurement of 5-HTOL is used as a sensitive biomarker for detection of recent alcohol intake. This study describes the development and evaluation of a liquid chromatography-electrospray ionization mass spectrometry (LC-MS) procedure for direct quantification of GTOL in human urine. Deuterium labelled GTOL (GTOL-(2)H(4)) was used as internal standard. GTOL was isolated from urine by solid-phase extraction on a C(18) cartridge prior to injection onto a gradient eluted Hypurity C(18) reversed-phase HPLC column. The detection limit of the method was 2.0 nmol/L and the measuring range 6-8500 nmol/L. The intra- and inter-assay coefficients of variation were <3.5% (n=10) and <6.0% (n=9), respectively. The new LC-MS method was highly correlated with an established GC-MS method for urinary 5-HTOL (r(2)=0.99, n=70; mean 5-HTOL/GTOL ratio=1.10). This is the first direct assay for quantification of GTOL in urine. The method is suitable for routine application.
Stephanson
Nikolai
N
Department of Medicine, Division of Clinical Pharmacology, Karolinska Institute and University Hospital, SE-17176 Stockholm, Sweden.
Dahl
Helen
H
Helander
Anders
A
Beck
Olof
O
D006916:5-Hydroxytryptophan / Q000031:analogs & derivatives* / Q000652:urine*; D000428:Alcohol Drinking / Q000652:urine*; D015415:Biomarkers / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D020719:Glucuronides / Q000652:urine*; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine; D006917:Hydroxytryptophol / Q000031:analogs & derivatives; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
C500750:5-hydroxytryptophol glucuronide; D015415:Biomarkers; D020719:Glucuronides; D006917:Hydroxytryptophol; D006897:Hydroxyindoleacetic Acid; D006916:5-Hydroxytryptophan