title: Thin-Layer Chromatography/Desorption Atmospheric Pressure Photoionization Orbitrap Mass Spectrometry of Lipids.
abstract: Desorption atmospheric pressure photoionization (DAPPI) allows surface analysis in the open atmosphere and is thus an appropriate method for the direct coupling of thin-layer chromatography (TLC) and mass spectrometry (MS). Here, the capability of DAPPI-MS for ionizing and detecting lipids, namely, cholesterol, triacylglycerols, 1,2-diol diesters, wax esters, cholesteryl esters, and hydrocarbons, from TLC and high-performance thin-layer chromatography (HPTLC) plates in MS and MS2modes was tested. Limits of detection for lipid standards separated using normal-phase (NP)-TLC and NP-HPTLC were established. TLC/DAPPI-MS was applied for lipids of vernix caseosa, a white creamy proteolipid biofilm that progressively coats the fetus during the last trimester of the pregnancy, and plant oils including caraway, parsley, safflower, and jojoba oils. Various lipids were identified by means of high resolution/accurate mass measurement of Orbitrap and comparison of the retardation factors with standards. Lipid class separation was carried out on the NP-HPTLC plates, whereas individual triacylglycerol and wax ester species were separated on the reversed-phase HPTLC plates. DAPPI-MS was found to be a simple, rapid, and efficient approach for detecting lipids separated by TLC.
authors.affiliation: The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.|Department of Analytical Chemistry, Faculty of Science, Charles University in Prague , 128 43 Prague 2, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Rejšek
authors.affiliation: The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Vrkoslav
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, 00014 Helsinki, Finland.
authors.forename: Anu
authors.initials: A
authors.lastname: Vaikkinen
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, 00014 Helsinki, Finland.
authors.forename: Markus
authors.initials: M
authors.lastname: Haapala
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, 00014 Helsinki, Finland.
authors.forename: Tiina J
authors.initials: TJ
authors.lastname: Kauppila
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki , P.O. Box 56, 00014 Helsinki, Finland.
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
authors.affiliation: The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.|Department of Analytical Chemistry, Faculty of Science, Charles University in Prague , 128 43 Prague 2, Czech Republic.
authors.forename: Josef
authors.identifier: 0000-0002-3590-9009
authors.initials: J
authors.lastname: Cvačka