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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #80249
Title: QUANTIFICATION OF CHOLESTEROL TRACERS BY GAS CHROMATOGRAPHY-NEGATIVE ION CHEMICAL IONIZATION MASS SPECTROMETRY

Author
item OSTLUND, RICHARD - WASHINGTON UNIVERSITY
item HSU, FONG-FU - WASHINGTON UNIVERSITY
item BOSNER, MATTHEW - WASHINGTON UNIVERSITY
item STENSON, WILLIAM - WASHINGTON UNIVERSITY
item Hachey, David - Dave

Submitted to: Mass Spectrometry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: We describe a state-of-the-art method known as gas chromatography-negative ion chemical ionization mass spectrometry (GC-NCI-MS). This is a high-sensitivity method for the analysis of isotopically labeled cholesterol. The method is a potentially valuable tool because of its high sensitivity in regard to studies involving the metabolism of cholesterol. Much research is being conducted on that subject because too much "bad" cholesterol can cause human beings serious problems. For example, cholesterol plaque can clog the arteries, leading to heart disease with potentially fatal consequences. Researchers find it important to use the best techniques available to analyze what happens to foods containing different amounts and types of cholesterol as these foods are ingested and go through the body. In order to accomplish their objective, they label the cholesterol with markers called isotopes and use the most sensitive technology available to analyze the isotopically labeled cholesterol.

Technical Abstract: Because of its high sensitivity, gas chromatography negative ion chemical ionization mass spectrometry (GC-NCI-MS) is a potentially valuable analytical tool for the study of cholesterol metabolism. Of several derivatives prepared for potential use in tracer studies,pentafluorobenzoyl cholesterol was selected because it formed rapidly at ambient temperature and was stable for long periods, could be detected at a level of 1 fmol, and yielded a mass spectrum in which the molecular ion was the principal component. Hexadeuterated cholesterol tracer ((26,26,26,27,27,27- 2H6)cholesterol) could be detected in dilutions up to 2700 in unlabeled cholesterol by selected ion monitoring with a coefficient of variation averaging 3.2%. In seven normal subjects, tracer cholesterol was infused intravenously and plasma cholesterol enrichment was determined after 4 h. The measured rapidly miscible cholesterol pool was 391.0 +/- 38.6 mg cholesterol/kg. Negative ion mass spectrometry of pentafluorobenzoyl cholesterol will facilitate analysis of both small amounts of natural cholesterol and labeled cholesterol in applications where sensitivity is critical.