Separation and Detection of Bile Acid 24-Glucuronides in Human Urine by Liquid Chromatography Combined with Electrospray Ionization Mass Spectrometry

Autor: Naoaki Murao, Hiroko Okuyama, Shigeo Ikegawa, Junji Oohashi, Junichi Goto
Rok vydání: 1999
Předmět:
Zdroj: Analytical Sciences. 15:625-631
ISSN: 1348-2246
0910-6340
DOI: 10.2116/analsci.15.625
Popis: A method for the separation and determination of bile acid 24-glucuronides using liquid chromatography (LC)/electro-spray ionization (ESI)-mass spectrometry (MS) has been developed. In the ESI mode, 24-glucuronides were characterized by an intense deprotonated molecule [M-H]- with a fragment ion [M-H-176]- formed by elimination of the glucuronic acid moiety. The ratio of these negative ions was significantly influenced by the orifice-1 and the ring lens voltages. Bile acid 24-glucuronides in human urine were extracted with an OASIS HLB cartridge and then subjected to the LC/ESI-MS analysis employing an 18O-labeled internal standard. The simultaneous separation was attained on a Develosil ODS-HG-5 column using 20 mM ammonium acetate (pH 6.0)-acetonitrile (3:1→3:2, v/v, 35 min) in a linear gradient elution mode, where the 24-glucuronides were monitored with a characteristic negative ion [M-H]-; the limit of detection was 10 fmol. This newly developed method was applied to the quantitation of bile acid 24-glucuronides in human urine with satisfactory selectivity and reliability.
Databáze: OpenAIRE
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