This project furthers the development of Solid Phase Micro-Extraction (SPME) techniques for the sampling and analysis of biogenic sesquiterpenes (SQTs) emitted to the atmosphere from terrestrial vegetation. SQTs are an important precursor to secondary organic aerosols (SOAs), whose sources are poorly characterized even though SOAs are critical in influencing global climate. SPME is a simple and relatively inexpensive sampling technique that limits contact between analyte compounds and surfaces relative to other gas phase sampling and analysis techniques. This is important for the analysis of SQTs due to their relatively low volatility and tendency to be lost to surfaces. The research employs laboratory plant enclosures and leaf cuvettes to determine SQT emissions rates. Experiments control for environmental conditions including light, temperature, humidity, and ambient carbon dioxide. SPME technology is tested systematically with respect to the analysis of SQTs and other biogenic volatile organic compounds (BVOCs). Emphasis is on determining the appropriate type of SPME fiber to use for sampling and analysis of various BVOCs, calibration using SPME, and storage of SPME fibers between sampling and analysis.
The project supports one Master's degree student and one undergraduate student throughout the period of the grant, giving these students at a non Ph.D. granting institution an opportunity to be involved in research and have meaningful data to present at regional and national conferences. The research work improves the resources available to students in teaching labs, and aids development of new lab experiments for undergraduate courses involving SPME and atmospheric chemistry. A new gas chromatography - mass spectrometry instrument is used for sample analysis and is also available to other users, thus constituting a new departmental resource. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
