title: Determination of carnitine, its short chain acyl esters and metabolic precursors trimethyllysine and gamma-butyrobetaine by quasi-solid phase extraction and MS/MS detection.
abstract: For the investigation of the metabolism and biosynthesis of carnitine, sensitive determination of carnitine and its metabolic precursors, trimethyllysine and gamma-butyrobetaine, is required. We present here a new simplified method for the analysis of carnitine, its acetyl- and propyl esters, as well as trimethyllysine and gamma-butyrobetaine without need for derivatization reactions by means of normal-phase LC and electrospray ionization tandem mass spectrometry. The limits of quantification were between 5 nM for acetyl carnitine and 70 nM for carnitine. Relative standard deviations in a fivefold determination of standard solutions were between <2% for carnitine and <10% for trimethyllysine. Quantifying the formation of deuterated carnitine from deuterated gamma-butyrobetaine, this method is also suitable for the determination of the activity of gamma-butyrobetaine dioxygenase in tissues.
authors.affiliation: Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 2, 06120 Halle/S., Germany. frank.hirche@landw.uni-halle.de
authors.forename: Frank
authors.initials: F
authors.lastname: Hirche
authors.forename: Maren
authors.initials: M
authors.lastname: Fischer
authors.forename: Janine
authors.initials: J
authors.lastname: Keller
authors.forename: Klaus
authors.initials: K
authors.lastname: Eder
mesh_terms: D000818:Animals; D001622:Betaine / Q000031:analogs & derivatives* / Q000378:metabolism; D002331:Carnitine / Q000737:chemistry* / Q000378:metabolism; D004952:Esters / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000031:analogs & derivatives* / Q000378:metabolism; D008297:Male; D052616:Solid Phase Extraction / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013552:Swine; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D004952:Esters; D001622:Betaine; C003712:trimethyllysine; C002889:gamma-butyrobetaine; D008239:Lysine; D002331:Carnitine