Simultaneous determination of methionine and total homocysteine in human plasma by gas chromatography-mass spectrometry

Citation
Y. Shinohara et al., Simultaneous determination of methionine and total homocysteine in human plasma by gas chromatography-mass spectrometry, J CHROMAT B, 758(2), 2001, pp. 283-288
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis
Journal title
JOURNAL OF CHROMATOGRAPHY B
ISSN journal
1387-2273 → ACNP
Volume
758
Issue
2
Year of publication
2001
Pages
283 - 288
Database
ISI
SICI code
1387-2273(20010715)758:2<283:SDOMAT>2.0.ZU;2-U
Abstract
A gas chromatographic-mass spectrometric method for the simultaneous determ ination of methionine and total homocysteine in human plasma is described. DL-[H-2(4)]Methionine and DL-[H-2(8)]homocystine were used as internal stan dards. The method involved reduction of the disulfide bond with dithiothrei tol, purification by cation-exchange chromatography using a BondElut SCX ca rtridge and derivatization with isobutyl chlorocarbonate in water-ethanol-p yridine. Quantitation was performed by selected-ion monitoring of the quasi -molecular ions of N(O,S)-isobutyloxycarbonyl ethyl ester (IBC-OEt) derivat ives for methionine and [H-2(4)]methionine, respectively, and the fragment ions ([M+H-COOisoBu-COOEt](+)) for IBC-OEt derivatives for homocysteine and [H-2(4)]homocysteine. respectively. The sensitivity, specificity. accuracy and precision of the method were demonstrated to be satisfactory for measu ring concentrations of methionine and total homocysteine in human plasma. ( C) 2001 Elsevier Science B.V. All rights reserved.