title: Analysis of 1,2-diol diesters in vernix caseosa by high-performance liquid chromatography - atmospheric pressure chemical ionization mass spectrometry.
abstract: Fatty acid diesters of long-chain 1,2-diols (1,2-DDE), or type II wax diesters, were analyzed in the vernix caseosa of a newborn girl. 1,2-DDE were isolated from the total lipid extract by the semipreparative TLC using plates coated with silica gel. Chromatographic separation of the 1,2-DDE molecular species was achieved on the non-aqueous reversed-phase HPLC with two Nova-Pak C18 columns connected in series (a total length of 45cm) and using an acetonitrile-ethyl acetate gradient. 1,2-DDE eluted from the column in the order of their equivalent chain number. The analytes were detected as ammonium adducts by an ion-trap mass spectrometer equipped with an atmospheric pressure chemical ionization source. Their structures were elucidated using tandem mass spectrometry with MS, MS(2) and MS(3) steps in a data-dependent mode. More than two thousand molecular species of 1,2-DDE were identified in 141 chromatographic peaks. The most abundant 1,2-DDE were monounsaturated lipids consisting of a C22 diol and a C18:1 fatty acid together with C16:0, C14:0 or C15:0 fatty acids. The positions of double bonds were characterized by the fragmentation of [M+C3H5N](+) formed in the ion source.
authors.affiliation: Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 43 Prague 2, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Šubčíková
authors.affiliation: Institute of Organic Chemistry and Biochemistry v.v.i., Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Hoskovec
authors.affiliation: Institute of Organic Chemistry and Biochemistry v.v.i., Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Vrkoslav
authors.affiliation: Joachim Barrande Grammar School, Talichova 824, CZ-266 01 Beroun, Czech Republic.
authors.forename: Tereza
authors.initials: T
authors.lastname: Čmelíková
authors.affiliation: Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 43 Prague 2, Czech Republic; Institute of Organic Chemistry and Biochemistry v.v.i., Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Háková
authors.affiliation: Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 43 Prague 2, Czech Republic; Institute of Organic Chemistry and Biochemistry v.v.i., Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic.
authors.forename: Radka
authors.initials: R
authors.lastname: Míková
authors.affiliation: Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, CZ-128 43 Prague 2, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Coufal
authors.affiliation: Department of Obstetrics and Gynaecology, General Faculty Hospital and 1st Faculty of Medicine, Charles University in Prague, Apolinářská 18, CZ-128 00 Prague 2, Czech Republic.
authors.forename: Antonín
authors.initials: A
authors.lastname: Doležal
authors.affiliation: Department of Obstetrics and Gynaecology, General Faculty Hospital and 1st Faculty of Medicine, Charles University in Prague, Apolinářská 18, CZ-128 00 Prague 2, Czech Republic.
authors.forename: Richard
authors.initials: R
authors.lastname: Plavka
authors.affiliation: Institute of Organic Chemistry and Biochemistry v.v.i., Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic. Electronic address: cvacka@uochb.cas.cz.
authors.forename: Josef
authors.initials: J
authors.lastname: Cvačka
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D013058:Mass Spectrometry; D014708:Vernix Caseosa / Q000737:chemistry*
chemical_list: D005227:Fatty Acids
keywords: Double-bond position; Lipidomics; Mass spectrometry; Neutral lipids; Skin lipids