title: Analysis of oxysterols and vitamin D metabolites in mouse brain and cell line samples by ultra-high-performance liquid chromatography-atmospheric pressure photoionization-mass spectrometry.
abstract: We have developed an ultra-high-performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometric (UHPLC-APPI-MS/MS) method for the simultaneous quantitative analyses of several oxysterols and vitamin D metabolites in mouse brain and cell line samples. An UHPLC-APPI-high resolution mass spectrometric (UHPLC-APPI-HRMS) method that uses a quadrupole-time of flight mass spectrometer was also developed for confirmatory analysis and for the identification of non-targeted oxysterols. Both methods showed good quantitative performance. Furthermore, APPI provides high ionization efficiency for determining oxysterols and vitamin D related compounds without the time consuming derivatization step needed in the conventionally used electrospray ionization method to achieve acceptable sensitivity. Several oxysterols were quantified in mouse brain and cell line samples. Additionally, 25-hydroxyvitamin D3 was detected in mouse brain samples for the first time.
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014, Finland. Electronic address: linda.ahonen@helsinki.fi.
authors.forename: Linda
authors.initials: L
authors.lastname: Ahonen
authors.affiliation: Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands. Electronic address: f.b.r.maire@lacdr.leidenuniv.nl.
authors.forename: Florian B R
authors.initials: FB
authors.lastname: Maire
authors.affiliation: Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014, Finland. Electronic address: mari.savolainen@helsinki.fi.
authors.forename: Mari
authors.initials: M
authors.lastname: Savolainen
authors.affiliation: Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014, Finland. Electronic address: jaakko.kopra@helsinki.fi.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kopra
authors.affiliation: Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands; Netherlands Metabolomics Centre, Leiden University, P.O. Box 9502, 22300 RA Leiden, The Netherlands. Electronic address: r.vreeken@lacdr.leidenuniv.nl.
authors.forename: Rob J
authors.initials: RJ
authors.lastname: Vreeken
authors.affiliation: Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands; Netherlands Metabolomics Centre, Leiden University, P.O. Box 9502, 22300 RA Leiden, The Netherlands. Electronic address: hankemeier@lacdr.leidenuniv.nl.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hankemeier
authors.affiliation: Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014, Finland. Electronic address: timo.myohanen@helsinki.fi.
authors.forename: Timo
authors.initials: T
authors.lastname: Myöhänen
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014, Finland. Electronic address: petri.kylli@helsinki.fi.
authors.forename: Petri
authors.initials: P
authors.lastname: Kylli
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014, Finland. Electronic address: risto.kostiainen@helsinki.fi.
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
mesh_terms: D000818:Animals; D001274:Atmospheric Pressure; D001923:Brain Chemistry; D002112:Calcifediol / Q000032:analysis; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005240:Feasibility Studies; D006801:Humans; D051379:Mice; D013261:Sterols / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods; D014807:Vitamin D / Q000032:analysis* / Q000378:metabolism
chemical_list: D013261:Sterols; D014807:Vitamin D; D002112:Calcifediol
keywords: Atmospheric pressure photoionization; Cell line samples; Liquid chromatography–mass spectrometry; Mouse brain samples; Oxysterols; Vitamin D