title: Localization of double bonds in triacylglycerols using high-performance liquid chromatography/atmospheric pressure chemical ionization ion-trap mass spectrometry.
abstract: A method for localizing double bonds in triacylglycerols using high-performance liquid chromatography-tandem mass spectrometry with atmospheric pressure chemical ionization (APCI) was developed. The technique was based on collision-induced dissociation or pulsed Q collision-induced dissociation of the C3H5N(+•) adducts ([M + 55](+•)) formed in the presence of acetonitrile in the APCI source. The spectra were investigated using a large series of standards obtained from commercial sources and prepared by randomization. The fragmentation spectra made it possible to determine (i) the total number of carbons and double bonds in the molecule, (ii) the number of carbons and double bonds in acyls, (iii) the acyl in the sn-2 position on the glycerol backbone, and (iv) the double-bond positions in acyls. The double-bond positions were determined based on two types of fragments (alpha and omega ions) formed by cleavages of C-C bonds vinylic to the original double bond. The composition of the acyls and their positions on glycerol were established from the masses and intensities of the ions formed by the elimination of fatty acids from the [M + 55](+•) precursor. The method was applied for the analysis of triacylglycerols in olive oil and vernix caseosa.
authors.affiliation: Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 128 43, Prague 2, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Háková
authors.forename: Vladimír
authors.initials: V
authors.lastname: Vrkoslav
authors.forename: Radka
authors.initials: R
authors.lastname: Míková
authors.forename: Karolina
authors.initials: K
authors.lastname: Schwarzová-Pecková
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Bosáková
authors.forename: Josef
authors.initials: J
authors.lastname: Cvačka
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D001274:Atmospheric Pressure; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D013058:Mass Spectrometry / Q000379:methods*; D000069463:Olive Oil / Q000737:chemistry; D014280:Triglycerides / Q000032:analysis*; D014708:Vernix Caseosa / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D000069463:Olive Oil; D014280:Triglycerides; C032159:acetonitrile