title: Determination of total cholesterol in serum by liquid chromatography-isotope dilution mass spectrometry.
abstract: We have developed a liquid chromatography-isotope dilution mass spectrometry procedure to quantify total cholesterol in serum. A particle-beam interface was used for coupling the liquid chromatograph and the mass spectrometer. After electron impact ionization the ions m/z = 386 and m/z = 389 were used for selective ion monitoring of cholesterol and the internal standard [25,26,27-(13)C]cholesterol. The sample preparation steps required for serum materials are alkaline hydrolysis and an extraction of the cholesterol into the cyclohexane phase. Imprecision for the determination of cholesterol in control materials is typically <1.0%. The deviation from the certified reference values was <0.75% for all control materials tested. A method comparison of the results obtained by this method with those obtained by gas chromatography-isotope dilution mass spectrometry for n = 28 pooled human sera derived from samples analyzed in our routine laboratory did not show differences >2.5%.
authors.affiliation: Institute for Clinical Chemistry and Pathobiochemistry, Medical Faculty, University of Technology Aachen, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Kock
authors.forename: B
authors.initials: B
authors.lastname: Delvoux
authors.forename: H
authors.initials: H
authors.lastname: Greiling
mesh_terms: D016477:Artifacts; D002784:Cholesterol / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002784:Cholesterol