Development of Novel Electrospray Ionization Techniques for the Investigation of Multi-valent ionic clustering at elevated Temperatures

Models for the behaviour of electrolytic solutions are becoming more and more based on the molecular nature of the solutions. To date, however, fundamental theoretical models cannot predict the thermodynamic or thermaochemical properties of aqueous electrolytic solutions from supercooled to supercritical because of the complex nature of such calculations although great strdes are being made. In addition, however, great advances are being made in gas-phase chemistry such as fundamental cluster chemistry at Berkeley (especially for moderately sized water clusters). Our experimental program into the electrosprayed creation of ions is aimed at helping to bridge the gap between our HPMS thermochemical and spectroscopic measurements on low-ligand number univalent ions to high-ligand number multivalent ions over wide ranges of temperature. This program was born in cooperation with Professor Kebarle at Alberta and relies heavily on advances made in his and other laboratories.
We have modified a standard VG Trio-3 triple-quadrupole mass spectrometer by replacing the source housing with our own very large high-pump capacity source housing shown above. This is equipped with a 2300 L/s diffusion pump and a very large working area. Electrospray experimental voltages come from our home-made electronics distribution unit made by Sasha. While we await for our Equilibrium Electrospray ion source being machined since 1996, we are investigating the electrolytics solutions using the simplified ion source shown schematically on the left. Here instead of a "clean" manner in which to deliver the ions, we have adopted the early Kebarle design of a simple deflector plate, focussing, and reaction chamber. Early experiments are promising and underway. Inititial non-equilibrium measurements carried out on an earlier version of the ion source led us to design a siginificantly improved experiment with required high ion sensitivity using a home made hexapole filter. Our main experiment will employ 2 such units to bring ions gently into the first mass filter and subsequent CID chamber. Watch here for results of our new experiments currently in progress.
Long term uses in addition to the elucidation of fundamental reaction schemes are involved with the development of new theoretical approaches for the prediction of high temperature and pressure properties of various important geological species in water.
A few pics from the ESI lab

• Overall ESI experimental representation with labels
• The electronics console showing multi-channel scalar, Sasha's voltage provider, state of the art pdp-11/53 microcomputers.
• The early happy group

People and Contacts:

	Dr. Jamey K. Hovey Ion-cluster Laboratory Leader.
	Prof. Terry Seward Geochemistry Group Leader.		Dr. Oleg Suleimenov Postdoctoral Fellow (plans to start working with us soon ....

Email contacts:

Supported By:

• Swiss National Science Foundation,
• ETH Research Commission,
• Micromass, The Mass Spectrometry People

A collaborative effort including:

• Professor Paul Kebarle, Chemistry Department, The University of Alberta
• Dr. Alan Hogg and ALL of the people in the Mass Spectrometry Laboratory, Chemistry Department, The University of Alberta
• Professor Terry McMahon, Chemistry Department, The University of Waterloo
• The machinists and electronics personel here in the IMP workshop at the ETH ( Bruno Zürcher, Urs Graber, IMP; Urs Menet, IGMR).