Development and use of in-situ mass spectrometers
R. Timothy Short. Ph.D.
University of South Florida
Wednesday, June 28, 2006
Pacific Forum – 3:00 pm
The University of South Florida’s Center for Ocean Technology (COT) has developed underwater mass spectrometers for in situ chemical analysis of aqueous systems. To date, all systems have employed membrane sampling interfaces that allow sensitive detection of volatile organic compounds and dissolved gases. Recent field deployments include diurnal monitoring of primary productivity in the Hillsborough River ( Tampa, FL) by continuous measurements of dissolved gases (e.g., oxygen and carbon dioxide) and measurements of dissolved-gas depth profiles to 500 m in the Gulf of Mexico. Construction of a new underwater mass spectrometer system extends deployments to depths in excess of 1000 m. COT scientists and engineers have also been using micro-electromechanical systems (MEMS) techniques to fabricate micro-mass spectrometers in silicon and other novel materials. In particular, miniature and micro-cylindrical ion trap (CIT) mass spectrometers have been constructed using a variety of substrates. Array-based techniques are also being investigated to increase sensitivity.