title: Feasibility of desorption atmospheric pressure photoionization and desorption electrospray ionization mass spectrometry to monitor urinary steroid metabolites during pregnancy.
abstract: Steroids have important roles in the progress of pregnancy, and their study in maternal urine is a non-invasive method to monitor the steroid metabolome and its possible abnormalities. However, the current screening techniques of choice, namely immunoassays and gas and liquid chromatography-mass spectrometry, do not offer means for the rapid and non-targeted multi-analyte studies of large sample sets. In this study, we explore the feasibility of two ambient mass spectrometry methods in steroid fingerprinting. Urine samples from pregnant women were screened by desorption electrospray ionization (DESI) and desorption atmospheric pressure photoionization (DAPPI) Orbitrap high resolution mass spectrometry (HRMS). The urine samples were processed by solid phase extraction for the DESI measurements and by enzymatic hydrolysis and liquid-liquid-extraction for DAPPI. Consequently, steroid glucuronides and sulfates were detected by negative ion mode DESI-HRMS, and free steroids by positive ion mode DAPPI-HRMS. In DESI, signals of eleven steroid metabolite ions were found to increase as the pregnancy proceeded, and in DAPPI ten steroid ions showed at least an order of magnitude increase during pregnancy. In DESI, the increase was seen for ions corresponding to C18 and C21 steroid glucuronides, while DAPPI detected increased excretion of C19 and C21 steroids. Thus both techniques show promise for the steroid marker screening in pregnancy.
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: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 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: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 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: Tiina J
authors.initials: TJ
authors.lastname: Kauppila
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 166 10 Prague 6, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Cvačka
authors.affiliation: Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland. Electronic address: risto.kostiainen@helsinki.fi.
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
mesh_terms: D001274:Atmospheric Pressure; D005240:Feasibility Studies; D005260:Female; D005865:Gestational Age; D020719:Glucuronides / Q000737:chemistry; D006801:Humans; D007477:Ions / Q000737:chemistry; D008027:Light; D011247:Pregnancy; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization; D013256:Steroids / Q000302:isolation & purification / Q000378:metabolism / Q000652:urine*; D013431:Sulfates / Q000737:chemistry
chemical_list: D020719:Glucuronides; D007477:Ions; D013256:Steroids; D013431:Sulfates
keywords: Desorption atmospheric pressure photoionization; Desorption electrospray ionization; Mass spectrometry; Metabolism; Pregnancy; Steroid