Knighton Research Projects
To continue to refine and improve drift tube reaction mass spectrometry for the analysis of selected hydrocarbons in challenging measurement environments. The analysis of complex mixtures directly by chemical ionization spectrometry techniques like the PTR-MS is often complicated by ion fragmentation and ionization of interfering compounds. Two important air toxic compounds 1,3-butadiene and acrolein are listed as emission components in aircraft exhaust. Presently there are no existing technologies capable of reliably measuring these components in aircraft exhaust. Knowledge about the emissions of compounds from aircraft is important towards understanding the influence that commercial aircraft may have on human health. While the PTR-MS provides a response to both 1,3-butadiene and acrolein, interferences from other aircraft exhaust compounds notably water and the isomeric butenes makes the direct analysis of these componenets impossible. Funding from NSF and FAA is being used to work on a series of techniques to allow for the analysis of these compounds.
- Designing simple chemical scrubbers that selectively remove interfering compounds so that traditional PTR-MS techniques can be employed.
- Discovering and learning how to produce new reagent ions that react selectively with either 1,3-butadiene and acrolein but not the other interfering compounds.
- Develop MS/MS methods using a newly built triple quadrupole drift tube reaction mass spectrometer. The first study envisioned for this instrument is to use MS/MS to resolve mixtures of protonated acrolein C3H4OH+ and protonated butene C4H8H+.
E. Velasco, B. Lamb, H. Westberg, E. Allwine, J. L. Arriaga-Colina, B. T. Jobson, M. Alexander, P. Prazeller, W. B. Knighton, T. M. Rogers, M. Grutter, S. C. Herndon, C. E. Kolb, M. Zavala, B. de Foy, R. Volkamer, L. T. Molina, M. J. Molina, "Distribution, magnitudes, reactivities, ration of diurnal patterns of volatile organic compounds in the Valley of Mexico during the MCMA 2002 and 2003 field campaigns." Atmos. Chem. Phys. Discuss., 6, 7563 (2006)
M. Zavala, S. C. Herndon, R. S. Slott, E. J. Dunlea, L. C. Marr, J. H. Shorter, M. Zahniser, W. B. Knighton, T. M. Rogers, C. E. Kolb, L. T. Molina and M. J. Molina, "Characterization of on-road emissions in the Mexico City Metropolitan Area using a mobile laboratory in chase and fleet average modes during the MCMA-2003 field campaign." Atmos. Chem. Phys. Discuss., 6, 4689 (2006).
Scott C. Herndon, Todd Rogers, Edward J. Dunlea, John T. Jaynes, RIchard miake-Lye and Berk Knighton, "Hydrocarbon emissions from in-use commercial aircraft during airport operations.." Environ. Sci. Technol. 40, 4406 (2006).
T. M. Rogers, E. P. Grimsrud, S. C. Herndon, J. T. Jayne, C. E. Kolb, E. Allwine, H. Westburg, B. K. Lamb, M. Zavala, L. T. Molina, M. J. Molina and W. B. Knighton, "On-road measurements of volatile organic compounds in the Mexico City metropolitan area using proton transfer reaction mass spectrometry." Int. J. Mass Spec., 252, 26 (2006)
Scott C. Herndon, John T. Jayne, Mark S. Zahniser, Douglas R. Worsnop, Berk Knighton, Eugene Allsine, Brian K. Lamb, Miguel Zavala, David D. nelson, J. Barry McManus, Joanne H. Shorter, Manjulas R. Canagaratna, Timothy B. Onash and Charles E. Kolb, "Characterization of urban pollutant emisssion fluxes and ambient concentration distributions using a mobile laboratory with rapid response instrumentation." Faraday Discuss., 130, 1 (2005)
M. Jiang, L. C. Marr, E. J. Dunlea, S. C. Herndon, J. T. Jayne, C. E. Kolb, W. B. Knighton, T. M. Rogers, M. Zavala, L. T. Molina, M. J. Molina, "Mobile laboratory measurements of black carbon, polycyclis aromatic hydrocarbons and other vehicle emissions in Mexico City." Atmos. Chem. Phys., 5, 3377 (2005)
David Ezra, Justin Jasper, Todd Rogers, Berk Knighton, Eric Grimsrud and Gary Strobel, "Proton transfer reaction-mass spectrometry as a technique to measure volatile emissions of Muscodor albus." Plant Science, 166, 1471 (2004)
Jennifer B. Mei, Gary A. Reineccius, W. Berk Knighton and Eric P. Grimsrud, "The Influence of Strawberry Yogurt Composition on Aroma Release." J. Agric. and Food Chem., 52, 6267 (2004)
Brad Fritz, Brian Lamb, Hal Westberg, Richard Folk, Berk Knighton and Eric Grimsrud, "Pilot- and full-scale measurements of VOC emissions from lumber drying on Inland Northwest species." Forest Prod. J., 54(6), 50 (2004)