title: Analysis of acylcarnitines as their N-demethylated ester derivatives by gas chromatography-chemical ionization mass spectrometry.
abstract: A novel approach to the analysis of acylcarnitines has been developed. It involves a direct esterification using propyl chloroformate in aqueous propanol followed by ion-pair extraction with potassium iodide into chloroform and subsequent on-column N-demethylation of the resulting acylcarnitine propyl ester iodides. The products, acyl N-demethylcarnitine propyl esters, are volatile and are easily analyzed by gas chromatography-chemical ionization mass spectrometry. For medium-chain-length (C4-C12) acylcarnitine standards, detection limits are demonstrated to be well below 1 ng starting material using selected ion monitoring. Well-separated gas chromatographic peaks and structure-specific mass spectra are obtained with samples of synthetic and biological origin. Seven acylcarnitines have been characterized in the urine of a patient suffering from medium-chain acyl-CoA dehydrogenase deficiency.
authors.affiliation: MSU-NIH Mass Spectrometry Facility, Department of Biochemistry, Michigan State University, East Lansing 48824-1319.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Huang
authors.forename: D A
authors.initials: DA
authors.lastname: Gage
authors.forename: L L
authors.initials: LL
authors.lastname: Bieber
authors.forename: C C
authors.initials: CC
authors.lastname: Sweeley
mesh_terms: D042964:Acyl-CoA Dehydrogenase; D044944:Acyl-CoA Dehydrogenases / Q000172:deficiency; D000215:Acylation; D002331:Carnitine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000652:urine; D006801:Humans; D008052:Lipid Metabolism, Inborn Errors / Q000652:urine; D015394:Molecular Structure; D016339:Spectrometry, Mass, Fast Atom Bombardment / Q000379:methods
chemical_list: D044944:Acyl-CoA Dehydrogenases; D042964:Acyl-CoA Dehydrogenase; D002331:Carnitine