My research interests involve the development of instrumentation and methods to monitor biological processes in tissue cultures in real-time. The instrument incorporates a cell incubation device with a cryofocusing inlet suitable for use with high-speed gas chromatography (GC). High-speed GC is capable of separating complex mixtures in one-tenth the time of conventional GC, on the order of seconds rather than minutes. These short analysis times make real-time monitoring of biological systems possible. The focus is on the detection and quantitation of the products of lipid peroxidation in model systems and tissue cultures. These products include alkanes, n-alkanals, alk-2-en-als, and 4-hydroxyalkenals. Direct monitoring is accomplished by focusing and concentrating gaseous products in the headspace of tissue cultures for injection into a time of flight (TOF) mass spectrometer. The high scanning rates of TOF instruments are compatible with high-speed GC, and the second dimension of data facilitates positive identification of analytes. This is a decided advantage for complex and dynamic biological systems.
CHEM 481 and 381 lab Instrumental Analysis
CHEM 281–282 Quantitative Analysis
CHEM 121–124 General Chemistry
Publications and Presentations
Measurement of Hexanal Production by Myoglobin-Induced Lipid Peroxidation Using a Miniature Incubator and Cryofocusing Inlet System with Gas Chromatography and Time-of-Flight Mass Spectrometry. Clifford, C.; Gutman, P.; Amunugama, M; Karunaratne, S.; Soltani, M.; Venkatachalam, K.; Pernecky, S.; Holmes, H. Chromatographia, in press, August, 2004.
Using Stationary Points on Potential Energy Surfaces to Model Intermolecular Interactions and Retention in Gas Chromatography. Knox, J. E.; Hratchian, H. P.; Trease, N.; Struble, J.; Schlegel, H. B.; Holmes, H. Chromatographia, 2004, 59, 329–334.
Speciated Hydrocarbon Emissions and the Associated Local Ozone Production from an Automotive Gasoline Engine. Bohac, S. V.; Assanis, D. N.; Holmes, H. L. S. Int. Journal of Engine Research, 2004, 5, 53–70.
Vector Model for Window-Diagram Optimization of Tunable Column Ensembles for High-Speed GC. Smith (Holmes), H. L.; Sacks, R. D. J. Sep. Sci., 1998, 25, 37–44.