Thorsten Benter

Picture of Thorsten Benter
Assistant Professor, Chemistry
School of Physical Sciences
M.S., University of Kiel, Germany
PH.D., University of Kiel, Germany
Phone: 949 824 2373
Fax: 949 824 3168
Email: tbenter@uci.edu
University of California, Irvine
321 Rowland Hall
Mail Code: 2025
Irvine, CA 92697
Research Interests
Atmospheric and Analytical Chemistry
Appointments
Research Associate, University of Kiel, Germany.
Research Abstract


Studies in Atmospheric Chemistry are continuously challenging the analytical skills of researchers. The more insight is gained toward the detailed understanding of atmospheric processes the more sophisticated technology needs to be used to comprehend complex reaction pathways. Due to this complexity and the fact that atmospheric key compounds are often present only in trace amounts, critical parameters for modern analytical instrumentation in this field are high selectivity, sensitivity and temporal resolution.





The current research activities of the Benter Group focus on the development of laser ionization techniques for use in gas phase analytical chemistry. A very promising new method utilizes a combined atmospheric pressure inlet / ion source stage which enabled us to detect several atmospheric trace species at or below the pptV concentration level. Potential application fields are atmospheric laboratory and field studies, non-invasive medical diagnostics and combustion chemistry. In this approach, high spectral selectivity is achieved by means of resonance enhanced multiphoton ionization (REMPI). One or two color excitation pathways facilitate the resonant ionization processes. For mass selective detection time-of-flight analyzers are being used. This detection scheme allows for unequivocal identification of selected species in complex gas mixtures or reaction systems.





We have also employed two color pump probe REMPI MS methods to study the photodissociation dynamics of several oxygenated halogen species which play important roles in the chemistry of the stratosphere, e.g., the symmetric chlorine monoxide dimer, ClOOCl. Identification and quantification of primary products and the kinetic energy released into fragments upon photolysis provides very useful data towards a better understanding of the photochemistry of these compounds.





In addition to the above mentioned techniques, we use conventional electron impact ionization time of flight mass spectrometry for a variety of analytical gas phase determinations.

Publications
"Atmospheric Pressure Laser Ionization. An Analytical Technique for Highly Selective Detection of Ultralow Concentrations in the Gas Phase" Anal. Chem. 1999, 71, 3721.
"Photodissociation Dynamics of ClO Radicals in the Range (from 237 nm to 270 nm.) and at 205 nm and the Velocity Distribution of O(1D) atoms", S. Schmidt, Th. Benter, and R.N. Schindler; Chem. Phys. Lett. 1998, 282, 292.
"Identification of Nascent Products formed in the Laser Photolysis of CH3OCl and HOCl at 308 nm and around 235 nm. Total Cl-atom Quantum Yields and the State and Velocity Distributions of Cl(2Pj)". R.N. Schindler, M. Liesner, S. Schmidt, U. Kirchner, Th. Benter; J. Photochem. Photobiol. A: Chemistry 1997, 107, 9.
"Experimental Verification of Gas Phase Bromine Enrichment in Reactions of HOBr with Sea Salt Doped Ice Surfaces", U. Kirchner, Th. Benter, and R.N. Schindler; Ber. Bunsenges. Phys. Chem. 1997, 101, 975.
"UV/VIS-Absorption Spectra of HOBr and CH3OBr; Br(2P3/2) Atom Yields in the Photolysis of HOBr", Th. Benter, Feldmann, Chr., Kirchner, U., Schmidt, M., Schmidt, S., and Schindler, R. N.; Ber. Bunsenges. Phys. Chem. 1995, 99, 1144.
Professional Societies
ACS, Analytical Devision
Bunsengesellschaft fuer Physilaische Chemie (GER)
Last updated
10/04/2000