Thorsten Benter
School of Physical Sciences
PH.D., University of Kiel, Germany
321 Rowland Hall
Mail Code: 2025
Irvine, CA 92697
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.
https://faculty.uci.edu/profile/?facultyId=4506
10/04/2000