Comparison of cholesterol oxidation product preparation methods for subsequent gas chromatographic analysis

An evaluation was made of the stability of cholesterol hydroperoxides (CHPs) under the analytical conditions and preparation methods commonly used for determination and quantification of cholesterol oxidation products (COPs). CHPs were prepared by photoxidation and separated by silica thin-layer chr...

Full description

Saved in:
Bibliographic Details
Published in:Journal of AOAC International 2004-03, Vol.87 (2), p.474-480
Main Authors: Rodriguez-Estrada, M.T, Costa, A, Pelillo, M, Caboni, M.F, Lercker, G
Format: Article
Language:English
Subjects:
Analytical biochemistry: general aspects, technics, instrumentation
Analytical, structural and metabolic biochemistry
Biological and medical sciences
cholesterol
Cholesterol - metabolism
cholesterol hydroperoxides
cholesterol oxidation products
Chromatography, Gas
Chromatography, Liquid
food analysis
foods
Fundamental and applied biological sciences. Psychology
gas chromatography
Mass Spectrometry
oxidation
Oxidation-Reduction
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:An evaluation was made of the stability of cholesterol hydroperoxides (CHPs) under the analytical conditions and preparation methods commonly used for determination and quantification of cholesterol oxidation products (COPs). CHPs were prepared by photoxidation and separated by silica thin-layer chromatography. CHPs were individually collected by normal-phase liquid chromatography and then subjected either to reduction or to cold saponification. The corresponding hydroxyl derivatives were generated by reduction, whereas cold saponification gave rise predominantly to 7-ketocholesterol. In another test, silylated and non-silylated CHPs were separately injected into a gas chromatograph at 310 degrees C, collected, and reinjected into a gas chromatography-mass spectrometry system. The silylated CHPs were more stable than the non-silylated ones, giving 7-ketocholesterol, 7alpha- and 7beta-hydroxycholesterol as main degradation products. Two unknown degradation peaks were detected in both silylated and nonsilylated CHPs, having 384 as main m/z fragment. The study of their mass spectra led to the conclusion that peaks A and B correspond to 6alpha- and 6beta-hydroxycholesterol, respectively.
ISSN:1060-3271
1944-7922
DOI:10.1093/jaoac/87.2.474