@article {BF-2407,
	title = {Eucalypt smoke and wildfires: Temperature dependent emissions of biogenic volatile organic compounds},
	journal = {International Journal of Mass Spectrometry},
	volume = {279},
	year = {2009},
	month = {01/2009},
	pages = {126 - 133},
	abstract = {Eucalypt contributions to biogenic sources of volatile organic compounds (VOCs) in Australia are estimated at teragram (Tg = 1012 g) amounts each year. Biogenic VOCs include plant-specific isoprenoids (isoprene and a range of terpenes) and other reactive organic compounds (i.e., acids, aldehydes and ketones). Atmospheric reactions of VOCs are numerous and many have significant environmental impact. Wildfires increase both the amounts of VOCs released and the complexity of their reactions. Proton-transfer reaction mass spectrometry (PTR-MS), gas chromatography mass spectrometry (GCMS) and direct analysis in real time (DART) mass spectrometry were applied to analyze release of VOCs as a function of temperatures ranging from ambient to combustion. PTR-MS enabled trace level analysis of VOCs from a complex forest atmosphere and revealed the release of terpenes associated with leaf damage during a storm. Temperature profile studies revealed ion abundances (i.e., emissions of VOCs) could be correlated with boiling points and vapor pressures of specific compounds. PTR-MS analysis of VOCs resulting from heating fresh leaf (E. grandis) material suggested that emissions of protonated methanol (m/z 33) and protonated acetaldehyde (m/z 45) were greatest at not, vert, similar60 {\textdegree}C while m/z 137 and 153 (associated with a series of terpenes) showed monotonic increases in ion abundance over a wide temperature range from ambient to 200 {\textdegree}C. GCMS analysis of fresh and senescent leaves of E. grandis showed that a series of VOCs (ethylvinylketone, diethylketone, 2-ethylfuran, hexanal and hexenals) are present only in fresh leaves while several terpenes (α and β pinenes, α-phellandrene, eucalyptol, γ-terpinene) were common in both. DART analysis of fresh leaf and stem of E. sideroxylon identified tissue-specific VOCs (e.g., methanol and ethanol were more abundant in stems). PTR-MS combustion studies of senescent leaves (E. grandis) identified two distinct, temperature-dependent VOC compositions. Before the appearance of smoke, the composition of VOCs remained consistent and correlated well with various naturally occurring isoprenoids, as observed in temperature profile studies. Sampling of eucalypt smoke suggested ions (m/z 75, 85, 87, 99, 111 and 125) correlated with protonated mass of oxygenated aldehydes, ketones, furans and substituted benzenes, and were due to pyrolysis of polycarbohydrates (cellulose and lignin) that are common in many types of wood.},
	doi = {10.1016/j.ijms.2008.10.027},
	author = {Maleknia, Simin D. and Bell, Tina and Adams, Mark A.}
}
@article {BF-2408,
	title = {Temperature-dependent release of volatile organic compounds of eucalypts by direct analysis in real time (DART) mass spectrometry},
	journal = {Rapid Communications in Mass Spectrometry},
	volume = {23},
	year = {2009},
	month = {08/2009},
	pages = {2241 - 2246},
	abstract = {A method is described for the rapid identification of biogenic, volatile organic compounds (VOCs) emitted by plants, including the analysis of the temperature dependence of those emissions. Direct analysis in real time (DART) enabled ionization of VOCs from stem and leaf of several eucalyptus species including E. cinerea, E. citriodora, E. nicholii and E. sideroxylon. Plant tissues were placed directly in the gap between the DART ionization source skimmer and the capillary inlet of the time-of-flight (TOF) mass spectrometer. Temperature-dependent emission of VOCs was achieved by adjusting the temperature of the helium gas into the DART ionization source at 50, 100, 200 and 300{\textdegree}C, which enabled direct evaporation of compounds, up to the onset of pyrolysis of plant fibres (i.e. cellulose and lignin). Accurate mass measurements facilitated by TOF mass spectrometry provided elemental compositions for the VOCs. A wide range of compounds was detected from simple organic compounds (i.e. methanol and acetone) to a series of monoterpenes (i.e. pinene, camphene, cymene, eucalyptol) common to many plant species, as well as several less abundant sesquiterpenes and flavonoids (i.e. naringenin, spathulenol, eucalyptin) with antioxidant and antimicrobial properties. The leaf and stem tissues for all four eucalypt species showed similar compounds. The relative abundances of methanol and ethanol were greater in stem wood than in leaf tissue suggesting that DART could be used to investigate the tissue-specific transport and emissions of VOCs},
	doi = {10.1002/rcm.4133},
	author = {Maleknia, Simin D. and Vail, Teresa M. and Cody, Robert B. and Sparkman, David O. and Bell, Tina and Adams, Mark A.}
}
@article {BF-1096,
	title = {Impact of volatile organic compounds from wildfires on crop production and quality},
	journal = {Aspects of Applied Biology },
	number = {88},
	year = {2008},
	month = {12/01/2008},
	pages = {93-97},
	author = {Maleknia, Simin D. and Adams, Mark A.}
}
@article {BF-2363,
	title = {PTR-MS analysis of reference and plant-emitted volatile organic compounds},
	journal = {International Journal of Mass Spectrometry},
	volume = {262},
	year = {2007},
	month = {05/2007},
	pages = {203 - 210},
	abstract = {Proton transfer reaction-mass spectrometry (PTR-MS) was applied to the analysis of a series of volatile organic compounds (VOCs) that emit from various plants. These include a group of alcohols (methanol, ethanol and butanol), carbonyl-containing compounds (acetic acid, acetone and benzaldehyde), isoprene, acetonitrile, tetrahydrofuran (THF), pyrazine, toluene and xylene and a series of terpenes (p-cymene, camphene, 2-carene, limonene, β-myrcene, α-pinene, β-pinene, γ-tepinene and terpinolene) and oxygen-containing terpenes (1,8-cineole and linalool). These mass spectral data were compared to an electron ionization (EI) database identifying that not all PTR-MS fragments were common to EI. PTR-MS studies of these reference compounds were utilized to identify VOCs emitted from Eucalyptus grandis leaf at a temperature range of 30{\textendash}100 {\textdegree}C. In addition to protonated molecules (M + H)+, abundant proton-bound dimers or trimers were detected for alcohols, acetone, acetonitrile and THF. Abundant fragment ions attributed to the loss of water from these proton-bound clusters were also observed. The stability of butyl (C4H9+ m/z 57) and acetyl (CH3CO+ m/z 43) fragment ions directed the proton-transfer reactions of butanol and acetic acid. Abundant (M + H)+ ions were detected for pyrazine, THF, toluene and xylene, as well as for all terpenes except those containing oxygen. For linalool and 1,8-cineole, the loss of water generated an abundant fragment ion at m/z 137. PTR-MS fragmentation patterns for terpenes were proposed for m/z 81 (C6H9+), 93 (C7H9+), 95 (C7H11+), 107 (C8H11+), 109 (C8H13+), 119 (C9H11+), 121 (C9H13+) and 137 (loss of water for oxygen-containing terpenes; C10H17+). The relative abundances of (M + H)+ and fragments for all terpenes (except linalool) were dependent on the drift tube voltage and the optimum voltage for detection of molecular ions was different for various terpenes.},
	doi = {10.1016/j.ijms.2006.11.010},
	author = {Maleknia, Simin D. and Bell, Tina and Adams, Mark A.}
}
