Chromatography Research Today is a free monthly online journal that collates and summarizes the latest research about Chromatography, including details on column chromatography, gas chromatography (gc), liquid chromatograpy, hplc.

Liquid chromatography-tandem mass spectrometry determination of plasma 24S-hydroxycholesterol with chromatographic separation of 25-hydroxycholesterol.

DeBarber AE, Lütjohann D, Merkens L, Steiner RD

Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239, USA. debarber@OHSU.edu

Concentrations of circulating 24S-hydroxycholesterol (24SOHChol) are of interest as a practical measure of cholesterol efflux from the human brain. The current method of choice for 24SOHChol quantification is with gas chromatography-mass spectrometry (GC-MS). Liquid chromatography-mass spectrometry (LC-MS) methods to detect 24SOHChol have been described, but they lack rigorous high-performance liquid chromatography (HPLC) separation of a closely eluting isomeric oxysterol, 25-hydroxycholesterol. This is important because 25-hydroxycholesterol can be present in significant amounts and tandem mass spectrometry (MS/MS) cannot completely differentiate 24SOHChol. We describe an LC-MS method with rapid chromatographic separation of the oxysterols to permit accurate determination of plasma 24SOHChol. The availability of an LC-MS method offers advantages such as simplified sample work-up and analysis.

Published 18 August 2008 in Anal Biochem, 381(1): 151-3.
Full-text of this article is available online (may require subscription).

© 2005-2009 Chromatography Research Today. All Rights Reserved.