Photodissociation of rhodamine ions in a quadrupole ion trap

PHYS 399

Nicholas A. Sassin,, Stephanie C. Everhart, Kent M. Ervin, and Joseph I. Cline. Department of Chemistry and Chemical Physics Program, University of Nevada, Reno, 1664 N. Virginia St./216, Reno, NV 89557
An electrospray/quadrupole ion trap/time-of-flight tandem mass spectrometer is used to study the photodissociation of rhodamine cations. The ions are formed in the electrospray source, trapped in the quadrupole, and irradiated with an argon ion laser at 514 nm. The laser beam enters through the ring electrode of the quadrupole ion trap. The reactant ions can be isolated in the trap and stored for predetermined amounts of time at a variable helium buffer gas pressure. Photodissociation processes are compared with collision-induced dissociation performed by exciting the ions kinetically in the trap. The results indicate that the interaction time with the laser, laser intensity, and buffer gas pressure inside the trap all affect the rates of dissociation. Mechanisms for the photodissociation process are considered using kinetic models.

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006