title: Effects of Solvent and Ion Source Pressure on the Analysis of Anabolic Steroids by Low Pressure Photoionization Mass Spectrometry.
abstract: Solvent and ion source pressure were two important factors relating to the photon induced ion-molecule reactions in low pressure photoionization (LPPI). In this work, four anabolic steroids were analyzed by LPPI mass spectrometry. Both the ion species present and their relative abundances could be controlled by switching the solvent and adjusting the ion source pressure. Whereas M•+, MH+, [M - H2O]+, and solvent adducts were observed in positive LPPI, [M - H]-and various oxidation products were abundant in negative LPPI. Changing the solvent greatly affected formation of the ion species in both positive and negative ion modes. The ion intensities of the solvent adduct and oxygen adduct were selectively enhanced when the ion source pressure was elevated from 68 to 800 Pa. The limit of detection could be decreased by increasing the ion source pressure. Graphical Abstract ᅟ.
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, China.
authors.forename: Chengyuan
authors.initials: C
authors.lastname: Liu
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, China.
authors.forename: Jiuzhong
authors.initials: J
authors.lastname: Yang
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, China.
authors.forename: Wan
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, University of California Davis, Davis, CA, 95616, USA.
authors.forename: Deen
authors.initials: D
authors.lastname: Lu
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, China. panyang@ustc.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Pan
keywords: Anabolic steroid; Low pressure photoionization; Mass spectrometry