title: Enhancement of ionization efficiency of mass spectrometric analysis from non-electrospray ionization friendly solvents with conventional and novel ionization techniques.
abstract: Electrospray ionization mass spectrometry (ESI-MS) has significantly impacted the analysis of complex biological and petroleum samples. However ESI-MS has limited ionization efficiency for samples in low dielectric and low polarity solvents. Addition of a make-up solvent through a T union or electrospray solvent through continuous flow extractive desorption electrospray ionization (CF-EDESI) enable ionization of analytes in non-ESI friendly solvents. A conventional make-up solvent addition setup was used and a CF-EDESI source was built for ionization of nitrogen-containing standards in hexane or hexane/isopropanol. Factors affecting the performance of both sources have been investigated and optimized. Both the make-up solvent addition and CF-EDESI improve the ionization efficiency for heteroatom compounds in non-ESI friendly solvents. Make-up solvent addition provides higher ionization efficiency than CF-EDESI. Neither the make-up solvent addition nor the CF-EDESI eliminates ionization suppression of nitrogen-containing compounds caused by compounds of the same chemical class.
authors.affiliation: Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, AB T6G 2G2, Canada.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.affiliation: Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, AB T6G 2G2, Canada. Electronic address: charles.lucy@ualberta.ca.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Lucy
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D010578:Petroleum / Q000032:analysis*; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation*; D014867:Water / Q000737:chemistry*
chemical_list: D010578:Petroleum; D012997:Solvents; D014867:Water; D019342:Acetic Acid; D000432:Methanol
keywords: Continuous flow-extractive desorption electrospray ionization; Electrospray; Make up solvent addition; Mass spectrometry; Petroleum