title: Comparison of derivatization/ionization techniques for liquid chromatography tandem mass spectrometry analysis of oxylipins.
abstract: The performance of two derivatization and ionization techniques for the quantitative reversed phase liquid chromatography (LC)- mass spectrometry (MS) analysis of hydroxy fatty acids (OH-PUFA) in plasma was evaluated: One used AMPP (N-(4-aminomethylphenyl)pyridinium chloride) leading to a positive charged amid-derivate which can be detected by electrospray ionization (ESI)-MS. Second yielded penta fluorobenzyl bromide (PFB) ester derivates allowing detection in electron capture atmospheric pressure chemical ionization (ecAPCI)-MS. The sensitivity of detection of a comprehensive set of hydroxy fatty acids of n6- and n3- poly unsaturated fatty acids was investigated. On the SCIEX3200 MS the applied PFB derivatization led to poor limits of detection (LOD) of 10-100nM (0.1-1pmol/0.03-0.3ng on column). By contrast, AMPP derivatization led to a similar sensitivity compared to the standard ESI(-) of non derivatized analytes (LOD about 1nM (10fmol/3pg on column)). For several analytes, including 9-HETE, 11-HETE and 17-HDHA the AMPP derivatization improved sensitivity enabling their detection in human plasma. However, precision was reduced by AMPP derivatization and variation in IS recovery indicated a strong matrix influence on the MS-signal. In sum, with the instrumentation used, neither of these derivatization methods improves in our hands the LC-MS based quantification of oxylipins.
authors.affiliation: Chair of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany; Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK.
authors.forename: Sven W
authors.initials: SW
authors.lastname: Meckelmann
authors.affiliation: Chair of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hellhake
authors.affiliation: Chair of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany.
authors.forename: Maryvonne
authors.initials: M
authors.lastname: Steuck
authors.affiliation: Chair of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Krohn
authors.affiliation: Chair of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany; Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany. Electronic address: nils@schebb-web.de.
authors.forename: Nils Helge
authors.initials: NH
authors.lastname: Schebb
mesh_terms: D001774:Blood Chemical Analysis; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D054883:Oxylipins / Q000037:antagonists & inhibitors* / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D054883:Oxylipins
keywords: AMPP; Derivatization; Eicosanoids; Lipidomics; Liquid chromatography mass spectrometry; Oxylipins