RYAN S. DABELL, PAMELA M. CHU, GERALD T. FRASER, GEORGE C. RHODERICK and RICHARD D. SUENRAM, National Institute of Standards and Technology, 100 Bureau Dr., Stop 8393, Gaithersburg, MD  20899

In this work, the first illustration of Fourier transform microwave spectroscopy (FTMW) as a tool for detection and quantification of multiple components in a gas-phase mixture is presented.  Long-term stability of the instrument response has been investigated and improved, and the current status of quantitative analysis has also been evaluated.

There is a continuing need for new analytical chemistry techniques to measure the concentration of trace gases for monitoring automobile exhaust, factory emissions, chemical warfare agents release, etc.  The high spectral resolution of FTMW (10 kHz at 10 GHz) provides a quick and unambiguous method for identifying multiple analytes in the gas phase.  Prior to this investigation, however, the technique has been untested in the examination of multiple analytes in a "real world" matrix, such as air.  The presence of CO2, H2O, O2, and other compounds that may interact with the analytes within the supersonic molecular beam is an important issue to consider in the application of analytical FTMW spectroscopy.