Skip to Main Content
 

Global Search Box

 
 
 

ETD Abstract Container

Abstract Header

Development of Ambient Mass Spectrometry for Protein/Peptide Characterization, Solvent-Free Analysis, and Electrochemical Reaction Monitoring

Liu, Pengyuan
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1419335862

Abstract Details

2015, Doctor of Philosophy (PhD), Ohio University, Chemistry (Arts and Sciences).
Ambient mass spectrometry (MS) refers to directly ionizing or analyzing samples with no or little preparation under ambient conditions. In this dissertation, three different ambient ionization techniques, including liquid sample desorption electrospray ionization (DESI), probe electrospray ionization (PESI), and nanospray DESI (nano-DESI), and one ambient ion dissociation method, atmospheric pressure thermal dissociation (APTD) have been developed. Liquid sample DESI generally uses one DESI probe to spray solvent to pick up and ionize samples in solution. When a certain ligand is sprayed to an injected protein solution instead of blank solvent, protein-ligand complex is formed during the fast DESI mixing and ionization process, providing a unique platform to study protein-ligand interactions. Furthermore, the fast mixing and direct sampling feature of liquid sample DESI also makes it possible to efficiently ionize phosphopeptides from a solution containing strong acids in which their deprotonation is inhibited, thus significantly increasing the ionization efficiency. Furthermore, online H/D exchange is also realized during the DESI fast mixing process by spraying deuterated solvents. PESI, another ambient ionization technique, employing a metallic probe to directly ionize samples on its tip, solvent-freely analyzes neat liquid and intact solid samples with thermally assisted probe, providing a useful way to ionize moisture-sensitive compounds. It is also applied to probe solvent-free reactions for the reaction monitoring and mechanism elucidation. Nano-DESI, a novel ambient ionization method which can be used for surface analysis, is used for online coupling with electrochemistry (EC). Especially, an interdigitated array (IDA) electrode is coupled for the first time. This novel coupling enables MS analysis of products of electrochemical reactions that take place on electrode surfaces. APTD involves the process in which precursor ions are directed into a heated coiled tube at atmospheric pressure to undergo dissociation. In addition to directly analyzing the fragment ions emitted from the APTD tube by MS, the fragment ions are also collected for a synthetic purpose. This novel preparative MS has much higher yield than in vacuum preparative MS methods. In particular, peptide b2 ions produced by APTD are collected, purified, and further analyzed by NMR, making the uncertain gas phase structure clearly elucidated. Furthermore, liquid sample DESI is coupled with APTD to post ionize the neutral fragments emitted from the heating tube of APTD apparatus, which are otherwise blind to MS and, thus, enhance the structural information obtained by APTD and elucidate gas phase fragmentation mechanisms.
Hao Chen (Advisor)
Tadeusz Malinski (Committee Member)
Peter Harrington (Committee Member)
Jeffrey Rack (Committee Member)
John Kopchick (Committee Member)
315 p.
Analytical Chemistry; Biochemistry; Chemistry
Ambient mass spectrometry; liquid sample desorption electrospray ionization; probe electrospray ionization; nanospray desorption electrospray ionization; atmospheric pressure thermal dissociation; proteomics; solvent-free; electrochemistry

Recommended Citations

Citations

  • Liu, P. (2015). Development of Ambient Mass Spectrometry for Protein/Peptide Characterization, Solvent-Free Analysis, and Electrochemical Reaction Monitoring [Doctoral dissertation, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1419335862

    APA Style (7th edition)

  • Liu, Pengyuan. Development of Ambient Mass Spectrometry for Protein/Peptide Characterization, Solvent-Free Analysis, and Electrochemical Reaction Monitoring. 2015. Ohio University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1419335862.

    MLA Style (8th edition)

  • Liu, Pengyuan. "Development of Ambient Mass Spectrometry for Protein/Peptide Characterization, Solvent-Free Analysis, and Electrochemical Reaction Monitoring." Doctoral dissertation, Ohio University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1419335862

    Chicago Manual of Style (17th edition)

ohiou1419335862
1,121
© 2015, all rights reserved.
This open access ETD is published by Ohio University and OhioLINK.