title: Quantification of pentafluorobenzyl oxime derivatives of long chain aldehydes by GC-MS analysis.
abstract: Negative ion mass spectrometric techniques, for compounds having good ionization properties, such as pentafluorobenzyl derivatives, are believed to be more sensitive than positive ion methods. Preparation of PFB oximes of fatty aldehydes from crude lipid extracts is problematic due to the release of free aldehydes from plasmalogens during derivatization. Accordingly, in these studies plasmalogens were removed by silicic acid column chromatography prior to pentafluorobenzyl derivatization. This simple purification step to remove plasmalogens is shown to facilitate the quantification of long-chain aldehydes by analysis of their pentafluorobenzyl oxime derivatives utilizing gas chromatography-mass spectrometry in the negative ion chemical ionization mode. The limit of detection for long chain fatty aldehydes using this method is 0.5 pmol and it is linear over two orders of magnitude. Silicic acid column chromatography followed by electrospray ionization mass spectrometry demonstrated that plasmalogens were removed (the detection limit for this analyses was <or=0.3 pmol). Furthermore, we have exploited the utility and sensitivity of this method to identify increases in hexadecanal and octadecanal in 3-amino-1,2,4-triazole treated human neutrophils.
authors.affiliation: Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, St Louis, MO 63104, USA.
authors.forename: Viral V
authors.initials: VV
authors.lastname: Brahmbhatt
authors.forename: Christopher
authors.initials: C
authors.lastname: Nold
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Albert
authors.forename: David A
authors.initials: DA
authors.lastname: Ford
mesh_terms: D000447:Aldehydes / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D005464:Fluorobenzenes / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D009504:Neutrophils / Q000737:chemistry; D010091:Oximes / Q000737:chemistry*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000447:Aldehydes; D005227:Fatty Acids; D005464:Fluorobenzenes; D010091:Oximes; C001634:fatty aldehyde; C001647:hexadecanal