Instrumentation for the Analysis of Biogenic Organic Compounds

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This award supports the purchase of a gas chromatograph-mass spectrometer (GC-MS) and proton transfer reaction-mass spectrometer (PTR-MS) for studies of the ecology, evolution and biochemistry of biogenic volatile organic compounds by seven investigators. While the GC-MS is often called the "gold standard" of chemical identification, its use is time consuming, often taking 45 min to analyze one sample completely. Thus the instrument does not lend itself to determination of rapidly changing dynamics in biosynthesis, emission or turnover, especially for volatile organic compounds. However, the PTR-MS can detect volatile compounds in a flowing air sample and can operate continuously for months, allowing for long-term, continuous measurements. Because this instrument lacks the ability to discriminate between two compounds of identical mass, its use often requires parallel use of GC-MS for compound validation. The research projects to be supported by the instruments include: (1) studies of volatile organic compound emissions from forest ecosystems, including their impact on ozone formation in the atmosphere, and subsequent deposition of ozone back to the forest; (2) biogenic volatile organic compounds as barometers of plant cellular metabolism and forest tree response to increasing atmospheric carbon dioxide; (3) studies of iridoid glycosides as deterrents of herbivory, including the possible role of metabolized glycosides as volatile cues for attracting parasites and predators of herbivores; (4) studies of the population genetics of terpene synthesis in plants and of the possible role of terpenes (which are typically associated with plant defense) as pollinator attractants; and (5) studies of the evolutionary co-option of surface waxes in eusocial bees for purposes of nestmate recognition and other forms of communication. The instruments will be used in research training of graduate and postdoctoral students. Additionally, the instruments are expected to serve a central role in supporting undergraduate training activities, including an NSF-funded Research Experiences for Undergraduates Program in which faculty users participate.