Premium
Quantitative determination of cholesterol sulphate in plasma by stable isotope dilution fast atom bombardment mass spectrometry
Author(s) -
Veares M. P.,
Evershed R. P.,
Prescott M. C.,
Goad L. J.
Publication year - 1990
Publication title -
biomedical and environmental mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0887-6134
DOI - 10.1002/bms.1200191002
Subject(s) - isotope dilution , chemistry , mass spectrometry , chromatography , cholesterol , fast atom bombardment , dilution , extraction (chemistry) , detection limit , biochemistry , physics , thermodynamics
A stable isotope dilution assay has been developed for the quantitative determination of cholesterol sulphate in plasma using negative ion fast atom bomardment (FAB) mass spectrometry. The assay is highly selective and avoids problems of contamination from free cholesterol and other conjugates of cholesterol present in plasma. (6,7,7‐ 2 H 3 )Cholesterol sulphate is used as the internal standard and solvent extraction and silica Sep‐Paks are employed to isolate plasma cholesterol sulphate. Limited‐range acceleration voltage scanning in FAB mass spectrometric analyses leads to sub‐microgram detection limits. Comparison of results obtained by FAB mass spectrometry of the intact cholesterol sulphate, and by gas chromatography/mass spectrometry selected ion monitoring of the free cholesterol, released by solvolysis of the cholesterol sulphate, showed that the latter approach probably overestimates plasma levels of cholesterol sulphate.