2A: Continued development of the High-Resolution Time-of-Flight version of the TOGA instrument

The ACOM Trace Organic Gas Analyzer (TOGA) is a fast gas chromatography - mass spectrometer used for in situ quantification of volatile organic compounds (VOCs), including those containing oxygen, sulfur and halogens. The instrument has been deployed on numerous field campaigns (particularly airborne campaigns sponsored by both NSF and NASA), and provides ambient data on roughly 70 species with 1 ppt sensitivity and 2-minute time resolution.

Recently, with the support of NSF special funds, TOGA has been coupled with a specialized time-of flight (TOF) mass spectrometer (MS) that is faster and produces a higher amount of data with more molecular information than the quadrupole mass spectrometer previously used. In fact, the technique provides much faster and more comprehensive analyses than any current competing technique allows and is positioned to revolutionize the organic gas analyses being done across different sub-disciplines by allowing for better peak separation based on mass defect, and increased, improved, and retroactive species identification from constant full spectra chromatograms. The instrument has the ability to detect and discover previously unmeasured chemicals in the atmosphere and to provide a comprehensive analysis of the complex organic gas chemistry of polluted air masses in cities, industrial zones, and forest fires as well as more pristine air over oceans and in forests. Figure 1 below shows the TOGA-TOF instrument as currently configured.

Figure 1. The TOGA-TOF instrument.
Figure 1. The TOGA-TOF instrument. TOF MS is on the left and the TOGA sample preparation system is on the right.