Progress 04/01/02 to 03/31/07
Outputs
Three areas of research were involved: (a) laboratory studies of the atmospheric chemistry of volatile organic compounds (VOCs) emitted into the atmosphere from biogenic sources, (b) laboratory studies of the kinetics and products of the gas-phase reactions of a series of alkyl phosphates, phosphonates, phosphorothioates and phosphonothioates which serve as model compounds for in-use pesticides, and (c) reviews and evaluations of kinetic and mechanistic literature data as part of an International Union of Pure and Applied Chemistry (IUPAC) data evaluation panel. We have used Solid Phase MicroExtraction fibers coated with a derivatizing agent to allow on-fiber derivatization of carbonyl compounds, which otherwise could not be analyzed by gas chromatography, to identify and quantify hydroxyaldehydes from the reactions of biogenic VOCs (including from isoprene, the most abundant biogenic VOC). These measurements have enabled us to obtain carbon balances for the reaction
products formed from the dominant daytime hydroxyl radical reaction for isoprene, 2-methyl-3-buten-2-ol and cis-3-hexene-1-ol. This on-fiber derivatization technique has also allowed us to investigate the kinetics of the further reactions of primary products formed from these biogenic VOCs. In addition, we have investigated the formation of hydroxyl radicals from the reactions of a series of monoterpenes with ozone and the products arising from the hydroxyl radical reaction of alpha-pinene. We have investigated the kinetics of the potential atmospheric reactions of a series of organophosphorus compounds, and shown that the only important gas-phase atmospheric reaction is with the hydroxyl radical and that the atmospheric lifetimes of these organophosphorus compounds are typically a few hours or less during daytime. Using in situ Fourier transform infrared spectroscopy and direct air sampling atmospheric pressure ionization tandem mass spectrometry, for the first time we have
identified, and in some cases quantified, the reaction products of these OH radical reactions. For the alkyl phosphorothioates and phosphonothioates studied, conversion of the P=S bond to a P=O bond was found to occur to a significant extent. The products observed allow reaction mechanisms to be derived for these alkyl phosphates, phosphonates, phosphorothioates and phosphonothioates, and these reaction mechanisms can be used to predict the first-generation atmospheric reaction products formed from actual in-use pesticides. Our results on the atmospheric reactions of biogenic VOCs and organophosphorus compounds have been published in the peer-reviewed literature. In addition, the isoprene and 2-methyl-3-buten-2-ol results are now included in the IUPAC data evaluations, which are freely available on the world-wide web (http://www.iupac-kinetic.ch.cam.ac.uk/) and in peer-reviewed journal publications. One of the PIs is a member of the IUPAC subcommittee on data evaluation for
atmospheric chemistry and these IUPAC evaluations facilitate the transfer of literature data, including ours, into chemical models which are used to predict urban and regional ozone and secondary particle formation.
Impacts
Our research provides for the first time a complete accounting of the products formed from the dominant daytime hydroxyl radical reactions of the most important biogenic emissions, including isoprene, 2-methyl-3-buten-2-ol and cis-3-hexene-1-ol. These data and additional information concerning the kinetics of the further reactions of primary products formed from these compounds have been published in the peer-reviewed literature. Through one of the PI's membership on the IUPAC subcommittee on data evaluation for atmospheric chemistry, literature data, including ours, is evaluated and recommendations made available to chemical modelers for input into models which are used to predict urban and regional ozone and secondary particle formation. Furthermore, reaction mechanisms derived from our kinetic and product studies of the atmospherically relevant reactions of alkyl phosphates, phosphonates, phosphorothioates and phosphonothioates can be used to predict the atmospheric
reaction products formed from actual in-use pesticides.
Publications
- Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J. and Troe, J. 2007. Evaluated kinetic and photochemical data for atmospheric chemistry: volume III reactions of inorganic halogens, Atmos. Chem. Phys., 7: 981-1191.
- Reissell, A., Aschmann, S. M., Atkinson, R. and Arey, J. 2002. Products of the OH radical and ozone-initiated reactions of myrcene and ocimene. J. Geophys. Res., 107 (D12), 10.1029/2001JD001234, ACH 3-1 to 3-6.
- Aschmann, S. M., Atkinson, R. and Arey, J. 2002. Products of the reaction of OH radicals with alpha-pinene. J. Geophys. Res., 107 (D14), 10.1029/2001JD001098, ACH 6-1 to 6-7.
- Aschmann, S. M., Arey, J. and Atkinson, R. 2002. OH radical formation from the gas-phase reactions of O3 with a series of terpenes. Atmos. Environ. 36: 4347-4355.
- Atkinson, R. and Arey, J. 2003. Gas-phase tropospheric chemistry of biogenic volatile organic compounds: a review. Atmos. Environ., 37 (Suppl. 2) S197-S219.
- Reissell, A., MacDonald, C., Roberts, P. and Arey, J. 2003. Characterization of biogenic volatile organic compounds and meteorology at Azusa during the SCOS97-NARSTO. Atmos. Environ. 37 (Suppl. 2): S181-S196.
- Reisen, F., Aschmann, S. M., Atkinson, R. and Arey, J. 2003. Hydroxyaldehyde products from hydroxyl radical reactions of z-3-hexen-1-ol and 2-methyl-3-buten-2-ol quantified by SPME and API-MS. Environ. Sci. Technol. 37: 4664-4671.
- Baker, J., Arey, J. and Atkinson, R. 2004. Kinetics of the gas-phase reactions of OH radicals, NO3 radicals and O3 with three C7-carbonyls formed from the atmospheric reactions of myrcene, ocimene and terpinolene. J. Atmos. Chem. 48: 241-260.
- Baker, J., Arey, J. and Atkinson, R. 2004. Rate constants for the gas-phase reactions of OH radicals with a series of hydroxyaldehydes at 296 +/- 2 K. J. Phys. Chem. A. 108: 7032-7037.
- Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J. and Troe, J. 2004. Evaluated kinetic and photochemical data for atmospheric modeling: volume 1 gas-phase reactions of Ox, HOx, NOx and SOx species. Atmos. Chem. Phys. 4: 1461-1738.
- Baker, J., Arey, J. and Atkinson, R. 2005. Formation and reaction of hydroxycarbonyls from the reaction of OH radicals with 1,3-butadiene and isoprene. Environ. Sci. Technol. 39:4091-4099.
- Aschmann, S. M., Tuazon, E. C. and Atkinson, R. 2005. Atmospheric chemistry of diethyl methylphosphonate, diethyl ethylphosphonate, and triethyl phosphate. J. Phys. Chem. A. 109: 2282-2291.
- Aschmann, S. M., Tuazon, E. C. and Atkinson, R. 2005. Atmospheric chemistry of dimethyl phosphonate, dimethyl methylphosphonate, and dimethyl ethylphosphonate. J. Phys. Chem. A. 109: 11828-11836.
- Aschmann, S. M., Long, W. D. and Atkinson, R. 2006. Temperature-dependent rate constants for the gas-phase reactions of OH radicals with 1,3,5-trimethylbenzene, triethyl phosphate, and a series of alkylphosphonates, J. Phys. Chem. A, 110: 7393-7400.
- Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J. and Troe, J. 2006. Evaluated kinetic and photochemical data for atmospheric chemistry: volume II gas phase reactions of organic species. Atmos. Chem. Phys., 6: 3625-4055.
- Aschmann, S. M. and Atkinson, R. 2006. A kinetic and product study of the gas-phase reactions of OH radicals, NO3 radicals and O3 with (C2H5O)2P(S)CH3 and (C2H5O)3PS, J. Phys. Chem. A, 110: 13029-13035.
- Tuazon, E. C., Aschmann, S. M. and Atkinson, R. 2007. Products of the gas-phase reactions of OH radicals with (C2H5O)2P(S)CH3 and (C2H5O)3PS, J. Phys. Chem. A, 111: 916-924.
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Progress 01/01/06 to 12/31/06
Outputs
We have investigated the kinetics of the potential atmospheric reactions of a series of organophosphorus compounds, and shown that the only important gas-phase atmospheric reaction is with the hydroxyl radical and that the atmospheric lifetimes of these organophosphorus compounds are typically a few hours or less during daytime. Using in situ Fourier transform infrared spectroscopy and in situ direct air sampling atmospheric pressure ionization tandem mass spectrometry, for the first time we have identified, and in some cases quantified, the reaction products of these OH radical reactions. The products observed allow reaction mechanisms to be derived for these alkyl phosphates and phosphonates, and these reaction mechanisms can be used to predict the first-generation atmospheric reaction products formed from actual in-use pesticides. Our previously reported results on the atmospheric reactions of the biogenic VOCs, isoprene and 2-methyl-3-buten-2-ol, are now included
in the IUPAC data evaluations, which are freely available on the world-wide web (http://www.iupac-kinetic.ch.cam.ac.uk/) and in peer-reviewed journal publications. One of the PIs is a member of the IUPAC subcommittee on data evaluation for atmospheric chemistry and these IUPAC evaluations facilitate the transfer of literature data, including ours, into chemical models which are used to predict urban and regional ozone and secondary particle formation.
Impacts
Our study of the atmospheric chemistry of six organophosphorus compounds, which serve as model compounds for commonly used pesticides, provides important life-time and, for the first time, product data for this class of compounds. Our previously reported results on the atmospheric reactions of the biogenic VOCs, isoprene and 2-methyl-3-buten-2-ol, are now included in the IUPAC data evaluations, which are freely available on the world-wide web. This IUPAC evaluation facilitates the transfer of literature data, including ours, into chemical models which are used to predict urban and regional ozone and secondary particle formation.
Publications
- Aschmann, S. M., Long, W. D. and Atkinson, R. 2006. Temperature-dependent rate constants for the gas-phase reactions of OH radicals with 1,3,5-trimethylbenzene, triethyl phosphate, and a series of alkylphosphonates, J. Phys. Chem. A, 110: 7393-7400.
- Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J. and Troe, J. 2006. Evaluated kinetic and photochemical data for atmospheric chemistry: volume II. gas phase reactions of organic species. Atmos. Chem. Phys., 6: 3625-4055.
- Aschmann, S. M. and Atkinson, R. 2006. A Kinetic and product study of the gas-phase reactions of OH radicals, NO3 radicals and O3 with (C2H5O)2P(S)CH3 and (C2H5O)3PS, J. Phys. Chem. A, 110: 13029-13035.
- Aschmann, S. M., Tuazon, E. C. and Atkinson, R. 2005. Atmospheric chemistry of dimethyl phosphonate, dimethyl methylphosphonate, and dimethyl ethylphosphonate. J. Phys. Chem. A. 109: 11828-11836.
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Progress 01/01/05 to 12/31/05
Outputs
During the last year we have continued to utilize our environmental chambers and analytical equipment to investigate the atmospheric chemistry of selected volatile organic compounds, both anthropogenic and biogenic. 1,3-Butadiene and isoprene (2-methyl-1,3-butadiene) are emitted into the atmosphere in vehicle exhaust and from vegetation, respectively. We have investigated the formation and further reaction of products of their hydroxyl radical-initiated reactions using atmospheric pressure ionization mass spectrometry (API-MS) and Solid Phase MicroExtraction fibers pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine for on-fiber derivatization of carbonyl compounds, with subsequent analysis by thermal desorption and gas chromatography with flame ionization detection (SPME/GC-FID) or MS detection. Hydroxycarbonyls were observed from SPME/GC-FID analyses of the 1,3-butadiene and isoprene reactions as their oximes, together with acrolein, glycolaldehyde and
glyoxal from the 1,3-butadiene reaction. A rate constant for the reaction of OH radicals with 4-hydroxy-2-butenal of (5.7 +/- 1.4) x 10-11 cm3 molecule-1 s-1 at 298 +/- 2 K was derived, and formation yields of acrolein and 4-hydroxy-2-butenal from the 1,3-butadiene reaction of 58 +/- 10% and 25%, respectively, were determined. Analogous experiments showed that the two C5-hydroxycarbonyls formed from isoprene have rate constants for their reactions with OH radicals of (1.0 +/- 0.2) x 10-10 cm3 molecule-1 s-1 and (4 +/- 2) x 10-11 cm3 molecule-1 s-1 and a combined yield of 15%, although isomer-specific identification of the hydroxycarbonyls was not achieved. Rate constants for the gas-phase reactions of OH radicals, NO3 radicals and ozone with three model organophosphorus compounds were measured at room temperature. No reactions with ozone were observed and the reactions with NO3 radicals were slow. Reaction with OH radicals will, therefore, dominate in the atmosphere. Diethyl phosphate
was observed as the major phosphorus-containing product from the OH radical reaction with triethyl phosphate.
Impacts
We have now not only identified hydroxycarbonyl products from hydroxyl radical-initiated reaction of the most significant biogenic volatile organic compound, isoprene, but we have measured the rates of their further reactions. This new laboratory data and the IUPAC evaluated data (publication 2 below) will provide important new inputs for modelers of urban and regional air pollution. The study of the atmospheric chemistry of three organophosphorus compounds, which serve as model compounds for commonly used pesticides, provides important life-time and, for the first time, product data for this class of compounds.
Publications
- Baker, J., Arey, J. and Atkinson, R. 2005. Formation and reaction of hydroxycarbonyls from the reaction of OH radicals with 1,3-butadiene and isoprene. Environ. Sci. Technol. 39:4091-4099.
- Atkinson, R., Baulch, D.L., Cox, R.A., Crowley, J.N., Hampson, R.F., Hynes, R.G., Jenkin, M.E., Rossi, M.J. and Troe, J. 2005. Evaluated kinetic and photochemical data for atmospheric modeling: volume 2 reactions of organic species. Atmos. Chem. Phys. Discuss. 5: 6295-7168.
- Aschmann, S.M., Tuazon, E.C. and Atkinson, R. 2005. Atmospheric chemistry of diethyl methylphosphonate, diethyl ethylphosphonate, and triethyl phosphate. J. Phys. Chem. A. 109: 2282-2291.
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Progress 01/01/04 to 12/31/04
Outputs
Biogenic volatile organic compounds (BVOCs) are emitted from vegetation and on a global basis these BVOC emissions far exceed anthropogenic VOCs. The highly reactive nature of many BVOCs makes understanding their atmospheric reactions important to understanding tropospheric ozone and secondary aerosol formation. During the last year we have extended our studies of the atmospheric chemistry of BVOCs to include studies of the atmospheric reaction rates of selected products formed from BVOCs. In one instance we synthesized a series of carbonyl compounds we have previously identified as formed from the atmospheric reactions of the BVOCs, myrcene, z- and e-ocimene and terpinolene. We then measured their rate constants for gas-phase reaction with hydroxyl (OH) radicals, nitrate (NO3) radicals and with ozone. Additionally we measured the rate constants for gas-phase reactions of OH radicals with hydroxyaldehydes formed in situ from OH radical-initiated reactions of the
BVOCs, 2-methyl-3-buten-2-ol and z-3-hexen-1-ol. In these latter studies, we continued to exploit our capability to measure hydroxyaldehydes using sampling on solid phase microextraction (SPME) fibers coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxyl amine for on-fiber derivatization to the oxime followed by gas chromatography with mass spectrometry identification and flame ionization detection quantification. During this time period one of the investigators (R. Atkinson) participated in an International Union of Pure and Applied Chemistry (IUPAC) panel evaluating atmospheric reactions. This panel published, in a freely-accessible on-line journal, an extensive data base available to the atmospheric sciences community.
Impacts
Both tropospheric ozone and ambient particles have been shown to produce adverse health impacts. The highly reactive nature of many BVOCs makes understanding their atmospheric reactions important to understanding the formation of tropospheric ozone and secondary aerosols. Our work is the first to report on the atmospheric reaction rates of the carbonyl and hydroxyaldehyde compounds studied. This new laboratory data and the IUPAC evaluated data will be important inputs for those modeling -urban and regional air pollution.
Publications
- Baker, J., Arey, J. and Atkinson, R. 2004. Kinetics of the gas-phase reactions of OH radicals, NO3 radicals and O3 with three C7-carbonyls formed from the atmospheric reactions of myrcene, ocimene and terpinolene. J. Atmos. Chem. 48: 241-260.
- Baker, J., Arey, J. and Atkinson, R. 2004. Rate constants for the gas-phase reactions of OH radicals with a series of hydroxyaldehydes at 296 +/- 2 K. J. Phys. Chem. A. 108: 7032-7037.
- Atkinson, R., Baulch, D.L., Cox, R.A., Crowley, J.N., Hampson, R.F., Hynes, R.G., Jenkin, M.E., Rossi, M.J. and Troe, J. 2004. Evaluated kinetic and photochemical data for atmospheric modeling: volume 1-reactions of Ox, HOx, NOx and SOx species. Atmos. Chem. Phys. Discuss. 3: 6179-6699; Atmos. Chem. Phys. 4: 1461-1738.
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Progress 01/01/03 to 12/31/03
Outputs
During the last year we have completed analysis of data from ambient measurements of isoprene and its atmospheric reaction products in the Los Angeles Air Basin and collaborated with meteorologists to model the transport and chemistry of these species. We have continued experimental studies on the atmospheric reaction products of biogenic volatile organic compounds (BVOCs) with a focus on the identification and quantification of the polar products and on assessments of the further reactions of the primary products. We have developed a sampling technique for the identification and quantification of hydroxyaldehydes involving sampling on a solid phase microextraction (SPME) fiber coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxyl amine for on-fiber derivatization to the oxime followed by gas chromatography with mass spectrometry identification and flame ionization detection quantification. We have utilized this technique to study the products formed from the hydroxyl
radical-initiated reactions of Z-3-hexen-1-ol, 2-methyl-3-buten-2-ol, isoprene and 1,3-butadiene. We also used direct air sampling atmospheric pressure ionization mass spectrometry to study these reactions and confirmed the formation of hydroxyaldehydes and also observed the formation of dihydroxynitrates. In the isoprene and 1,3-butadiene reactions we also determined the kinetics of the reactions of the first generation hydroxyaldehydes with the hydroxyl radical. These first generation hydroxyaldehyde products were formed in situ and rate constants derived from consecutive reaction theory. During this time period an extensive review of the atmospheric chemistry of biogenic organic compounds was also prepared and published.
Impacts
Our studies of the OH radical-initiated reactions of Z-3-hexen-1-ol, 2-methyl-3-buten-2-ol, isoprene and 1,3-butadiene provide a detailed understanding of the reaction mechanisms and products formed. We have developed a novel method for investigating the kinetics and products of hydroxyaldehyde compounds which cannot be purchased commercially, by forming them in situ in our reaction chambers. Our recently published review of the atmospheric chemistry of a large number of biogenic compounds, including their reaction products, provides a critical data base for modeling urban and regional air pollution.
Publications
- Reissell, A., MacDonald, C., Roberts, P. and Arey, J. 2003. Characterization of biogenic volatile organic compounds and meteorology at Azusa during the SCOS97-NARSTO. Atmos. Environ. 37 (Suppl. 2): S181-S196.
- Atkinson, R. and Arey, J. 2003. Gas-phase tropospheric chemistry of biogenic volatile organic compounds: a review. Atmos. Environ. 37 (Suppl. 2): S197-S217.
- Reisen, F., Aschmann, S.M., Atkinson, R. and Arey, J. 2003. Hydroxyaldehyde products from hydroxyl radical reactions of Z-3-hexen-1-ol and 2-methyl-3-buten-2-ol quantified by SPME and API-MS. Environ. Sci. Technol. 37: 4664-4671.
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Progress 01/01/02 to 12/31/02
Outputs
We have continued experimental studies on the atmospheric reaction products of biogenic volatile organic compounds (BVOCs) with a focus on the identification and quantification of the polar products and on assessments of the further reactions of the primary products. We have developed a sampling technique for the identification and quantification of hydroxyaldehydes involving sampling on a solid phase microextraction (SPME) fiber coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxyl amine for on-fiber derivatization to the oxime followed by gas chromatography with mass spectrometry identification and flame ionization detection quantification and utilized this technique to study the products formed from the OH radical-initiated reactions of Z-3-hexen-1-ol and 2-methyl-3-buten-2-ol. We also used direct air sampling atmospheric pressure ionization mass spectrometry to study these reactions and confirmed the formation of hydroxyaldehydes and also observed the formation of
dihydroxynitrates.
Impacts
Our studies of the OH radical-initiated reactions of Z-3-hexen-1-ol and 2-methyl-3-buten-2-ol provides a detailed understanding of the reaction mechanisms and products formed. Our review of the atmospheric chemistry of a large number of biogenic compounds, including their reaction products, provides a critical data base for modeling urban and regional air pollution.
Publications
- Aschmann, S.M., Arey, J. and Atkinson, R. 2002. OH radical formation from the gas-phase reactions of ozone with a series of terpenes. Atmospheric Environment 36: 4347-4355.
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Progress 01/01/01 to 12/31/01
Outputs
Agricultural crops, as well as natural vegetation, emit non-methane organic compounds into the atmosphere. During this project we have investigated of the atmospheric chemistry of biogenic compounds and made ambient measurements of biogenic species. The biogenic compounds, and their atmospheric reaction products, whose atmospheric chemistry we have investigated include: isoprene, methyl vinyl ketone, methacrolein, 3-methylfuran, alpha- and beta-pinene, myrcene, ocimene, limonene, terpinolene, sabinene, 3-carene, gamma-terpinene, alpha-terpinene, camphor, camphene, 2-methyl-3-buten-2-ol, pinonaldehyde, caronaldehyde and sabinaketone. We participated in the Southern California Ozone Study in 1997 and measured selected monoterpenes and isoprene and its atmospheric reaction products, methacrolein and methy vinyl ketone. The complex interaction of meteorology and atmospheric chemistry was demonstrated by biogenic compound measurements which indicated the occurrence of
nighttime nitrate radical chemistry at elevated sites in the Los Angeles air basin. During this project an on-going review and evaluation of reactions occurring in atmospheric chemistry was carried out as part of an International Union of Pure and Applied Chemistry project; initially these reviews were published in the peer-reviewed literature and now are available on the World Wide Web at http://www.iupac-kinetic.ch.cam.ac.uk/.
Impacts
Ozone control strategies depend upon modeling of emissions coupled with a detailed understanding of their atmospheric chemistry. Because of their high reactivity and abundance, biogenic compounds play a significant role in the formation of photochemical air pollution. Our studies of the atmospheric chemistry of a large number of biogenic compounds, including their reaction products, provides a critical data base for modeling urban and regional air pollution.
Publications
- Reissell, A., Aschmann, S.M., Atkinson, R. and Arey, J. 2002. Products of the OH radical and ozone-initiated reactions of myrcene and ocimene. J. Geophys. Res., in press.
- Aschmann, S.M., Atkinson, R. and Arey, J. 2002. Products of the reaction of OH radicals with alpha-pinene. J. Geophys. Res., in press.
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Progress 01/02/00 to 12/31/00
Outputs
Agricultural crops, as well as natural vegetation, emit non-methane organic compounds into the atmosphere. We have continued our investigations of the atmospheric chemistry of biogenic compounds and ambient measurements of biogenic species. During this year we have published our studies of the kinetics and products of the atmospheric reactions of camphor and of the kinetics of a series of unsaturated alcohols, including 2-methyl-3-buten-2-ol with OH radicals. We have published our analysis of our 1997 field study data showing the presence of biogenic compounds in the Los Angeles atmosphere and the importance of nighttime nitrate radical chemistry at elevated sites surrounding the basin. Two review and evaluation articles have also been published, dealing with the atmospheric chemistry of biogenic and anthropogenic compounds.
Impacts
Ozone control strategies depend upon modeling of emissions coupled with an understanding of atmospheric chemistry, and biogenic compounds, such as those whose chemistry we are studying, can play a significant role.
Publications
- Atkinson, R. 2000. Atmospheric chemistry of VOCs and NOx. Atmos. Environ. 34: 2063-2101.
- Atkinson, R., Baulch, D.L., Cox, R.A., Hampson, R. F., Jr., Kerr, J.A., Rossi, M.J. and Troe, J. 2000. Evaluated kinetic and photochemical data for atmospheric chemistry: Supplement VIII, Halogen Species. J. Phys. Chem. Ref. Data. 29: 167-266.
- Papagni, C., Arey, J. and R. Atkinson. 2001. Rate constants for the gas-phase reaction of OH radicals with a series of unsaturated alcohols. Int. J. Chem. Kinet. 33: 142-147.
- Reissell, A. and Arey, J. 2001. Biogenic volatile organic compounds at Azusa and elevated sites during the 1997 Southern California Ozone Study. J. Geophys. Res. 106: 1607-1621.
- Reissell, A., Arey, J. and Atkinson, R. 2001. Atmospheric chemistry of camphor. Int. J. Chem. Kinet. 33: 56-63.
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Progress 01/01/99 to 12/31/99
Outputs
Agricultural crops, as well as natural vegetation, emit non-methane organic compounds into the atmosphere. We have continued our investigations of the atmospheric chemistry of biogenic compounds including camphor and other biogenic compounds using gas chromatography with flame ionization detection, combined gas chromatography-mass spectrometry, in situ Fourier transform infrared spectroscopy and in situ atmospheric pressure ionization tandem mass spectrometry. During this year we have published our studies of the products of the reactions of 2-methyl-3-buten-2-ol with OH radicals and ozone, and the measured formation yields of acetone from the OH radical and ozone reactions of the monoterpenes camphene, 3-carene, limonene, myrcene, ocimene, alpha-phellandrene, alpha-pinene, beta-pinene, sabinene, alpha-terpinene, gamma-terpinene, and terpinolene, as well as from 2-methyl-3-buten-2-ol. Our measured acetone yields from the atmospheric photooxidations of biogenic
compounds show that in situ atmospheric formation of acetone from these species is an important source of acetone in the atmosphere and contributes to the chemistry of the atmosphere and to peroxyacetyl nitrate formation thoughout the global atmosphere.
Impacts
Our kinetic, product and mechanistic data are being used in computer chemical mechanisms for inclusion into urban and regional airshed models which predict ozone formation and, thereby allow control strategies to be developed.
Publications
- Alvarado, A., Tuazon, E.C., Aschmann, S.M., Arey, J. and Atkinson, R. 1999. Products and mechanisms of the gas-phase reactions of OH radicals and O3 with 2-methyl-3-buten-2-ol. Atmos. Environ. 33: 2893-2905.
- Atkinson, R., Baulch, D.L., Cox, R.A., Hampson, R.F., Jr., Kerr, J.A., Rossi, M.J., Troe, J. 1999. Evaluated kinetic and photochemical data for atmospheric chemistry, organic species: supplement VII. J. Phys. Chem. Ref. Data 28: 191-393.
- Dekermenjian, M., Allen, D.T., Atkinson, R. and Arey, J. 1999. FTIR analysis of aerosol formed in the ozone oxidation of sesquiterpenes. Aerosol Sci. Technol. 30: 349-363.
- Reisell, A., C. Harry, S.M. Aschmann, R. Atkinson and J. Arey. 1999. Formation of acetone from the OH radical- and O3-initiated reactions of a series of monoterpenes. J. Geophys. Res. 104: 13869-13879.
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Progress 01/01/98 to 12/01/98
Outputs
Non-methane organic compounds are emitted into the atmosphere from vegetation, including from agricultural crops and natural vegetation. During this year we have investigated the products of the reactions of 2-methyl-3-buten-2-ol with OH radicals and ozone, and measured the formation yields of acetone from the OH radical and ozone reactions of the monoterpenes camphene, 3-carene, limonene, myrcene, ocimene, alpha-phellandrene, alpha-pinene, beta-pinene, sabinene, alpha-terpinene, gamma-terpinene, and terpinolene. Using gas chromatography with flame ionization detection, combined gas chromatography-mass spectrometry, in situ Fourier transform infrared spectroscopy and in situ atmospheric pressure ionization tandem mass spectrometry, we identified and quantified formaldehyde, glycolaldehyde, acetone, and 2-hydroxy-2-methylpropanal from the OH radical and ozone reactions with 2-methyl-3-buten-2-ol, and organic nitrates were observed from the OH radical reaction. These
product data allowed us to formulate detailed chemical mechanisms for the atmospheric reactions of 2-methyl-3-buten-2-ol, which is emitted from various pine trees and which is estimated to contribute a significant fraction of total biogenic emissions. Almost all of the monoterpene reactions studied lead to the formation of acetone, with formation yields ranging from less than 2 percent for the OH radical and ozone reactions with limonene up to 45 percent for the OH radical reaction with myrcene. Combined with literature estimates of the emissions of monoterpenes and 2-methyl-3-buten-2-ol,.
Impacts
(N/A)
Publications
- ATKINSON, R., AREY, J. 1998. Atmospheric chemistry of biogenic organic compounds. Accounts of Chemical Research, vol. 31, pp.
- ALVARADO, A., TUAZON, E. C., ASCHMANN, S. M., ATKINSON, R., AREY, J. 1998. Products of the gas-phase reactions of O(3P) atoms and O3 with alpha-pinene and 1,2-dimethyl-1-cyclohexene. Journal of Geophysical Research, vol. 103, pp. 25541-.
- ASCHMANN, S. M., REISSELL, A., ATKINSON, R., AREY, J. 1998. Products of the gas phase reactions of the OH radical with alpha- and beta-pinene in the presence of NO. Journal of Geophysical Research,
- ALVARADO, A., AREY, J., ATKINSON, R. 1998. Kinetics of the gas-phase reactions of OH and NO3 radicals and O3 with the monoterpene reaction products pinonaldehyde, caronaldehyde, and sabinaketone. Journal of Atmospheric Chemistry, vol. 31,.
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Progress 10/01/96 to 12/01/97
Outputs
Non-methane organic compounds are emitted into the atmosphere from vegetation, including agricultural crops and natural vegetation. During this year we have (a) investigated the products of the reactions of alpha-pinene and beta-pinene with OH radicals and, for alpha-pinene, with ozone, and (b) measured the rate constants for the potentially important reactions of selected monoterpene reaction products (specifically pinonaldehyde, caronaldehyde and sabinaketone, products formed from alpha-pinene, 3-carene and sabinene, respectively). These studies were carried out in large-volume (7000-8000 liter) environmental chambers with analyses of reactants and products by gas chromatography, in situ atmospheric pressure ionization tandem mass spectrometry, and in situ Fourier transform infrared absorption spectroscopy. Specifically, we have carried out three studies, as briefly discussed below. The data obtained from the ozone reactions provide new information concerning the
reactions of the initially-formed biradicals, showing that they decompose mainly into an hydroxyl (OH) radical plus a substituted alkyl radical, and that the "thermalized" biradicals react with water vapor to form a carbonyl plus hydrogen peroxide. We identified the formation of hydroxynitrates, dihydroxynitrates, dihydroxycarbonyls and trihydroxycarbonyls/dihydroxydicarbonyls, in addition to the previously reported formation of pinonaldehyde from alpha-pinene and nopinone from beta-pinene. Our hydroxyl radical reaction rate constants for pinonaldehyde and caronaldehyde are both a factor of approximately 2.
Impacts
(N/A)
Publications
- CARTER, W. P. L., ATKINSON, R. 1996. Development and evaluation of a detailed mechanism for the atmospheric reactions of isoprene and NOx. International Journal of Chemical Kinetics, vol. 28, pp. 497-530.
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Progress 01/01/96 to 12/30/96
Outputs
Non-methane organic compounds are emitted into the atmosphere from agricultural crops and natural vegetation. Using flow-through Teflon enclosure techniques, the hydrocarbon emissions from shade trees and from ten native plant species of California's South Coast Air Basin (SOCAB) were measured. The shade trees were ranked in terms of their hydrocarbon emissions, for consideration by urban planners and horticulturists. For the ten native plant species, oxygenated hydrocarbons were observed as large emissions from certain aromatic sage and sagebrush species, and sesquiterpenes were found to be a high proportion of the emissions from Black Sage plants from late February to April. The isoprene emission rates measured for Quercus wislizenii and Quercus dumosa were lower than previously examined Quercus sp. However, estimated emissions of isoprene and terpenes from natural plant species in the SOCAB suggest that it may be difficult to reduce anthropogenic hydrocarbons
sufficiently to meet ambient air quality standards for ozone, and support the position that stringent controls on oxides of nitrogen as well as hydrocarbons may be required. The atmospheric chemistry of a series of monoterpenes and selected reaction products have been investigated. The aldehyde and ketone products from the hydroxyl radical and ozone reactions with several monoterpenes were identified and quantified, and the rate constants for the atmospherically important reactions of three monoterpene reaction products were measured.
Impacts
(N/A)
Publications
- AREY, J., CROWLEY, D. E., CROWLEY, M., RESKETO, M., LESTER, J. 1995. Hydrocarbon emissions from natural vegetation in California's South Coast Air Basin. Atmospheric Environment, 29: 2977-2988.
- ATKINSON, R., ASCHMANN, S. M. 1993. Atmospheric chemistry of the monoterpene reaction products nopinone, camphenilone, and 4-acetyl-l-methylcyclohexene. Journal of Atmospheric Chemistry, 16: 337-348.
- CARTER, W. P. L., ATKINSON, R. 1996. Development and evaluation of a detailed chemical mechanism for the atmospheric reactions of isoprene and NO(subscript x). International Journal of Chemical Kinetics, in press.
- CORCHNOY, S. B., AREY, J., ATKINSON, R. 1992. Hydrocarbon emissions from twelve urban shade trees of the Los Angeles, California, air basin. Atmospheric Environment, 26B: 339-348.
- HAKOLA, H., AREY, J., ASCHMANN, S. M., ATKINSON, R. 1994. Product formation fromthe gas-phase reactions of OH radicals and O(subscript 3) with a series of monoterpenes. Journal of Atmospheric Chemistry, 18: 75-102.
- HAKOLA, H., SHOREES, B., AREY, J., ATKINSON, R. 1993. Product formation from thegas-phase reactions of hydroxyl radicals and ozone with (beta)-phellandrene. Environmental Science & Technology, 27: 278-283.
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Progress 01/01/95 to 12/30/95
Outputs
Isoprene (2-methyl-1,3-butadiene) is emitted in substantial quantities from certain types of vegetation (including oaks), and comprises a large fraction of the organic compound emissions from vegetation on a regional scale. Isoprene is highly reactive in the atmosphere and participates in the formation of ozone and other manifestations of photochemical air pollution in urban and rural areas. It is therefore important that isoprene's atmospheric chemistry be understood and correctly represented in airshed computer models used to simulate urban and regional air quality. The most up-to-date kinetic and product data concerning the photooxidation of isoprene and of its reaction products (much of this data being obtained from our laboratory studies funded by the National Science Foundation and the U.S. Environmental Protection Agency) has been used to formulate and test a detailed chemical mechanism for isoprene's atmospheric reactions. This chemical mechanism was then
tested against environmental chamber data and certain areas of uncertainty in the mechanism adjusted to better fit the chamber data.
Impacts
(N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs
Hydrocarbon emissions from ten native plant species with high contributions to the biomass of California's South Coast Air Basin (SOCAB) were measured using a flow-through chamber enclosure technique. Camphor and cineole and other oxygenated hydrocarbons were observed to be large emissions from certain aromatic sage and sagebrush species. Representative emission rate measurements for these species were difficult to obtain using the enclosure technique. Sesquiterpenes were found to be a high proportion of the emissions from Black Sage plants from late February to April. The isoprene emission rates measured for Interior Live Oak (Quercus wislizenii) and Scrub Oak (Quercus dumosa) were lower than most previously examined Quercus sp. However, estimated emissions of isoprene and terpenes from natural plant species in the SOCAB suggest that it may be difficult to reduce anthropogenic hydrocarbons sufficiently to meet ambient air quality standards for ozone and support the
position that stringent controls on NOx as well as hydrocarbons will be required.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
Non-methane organic compounds are emitted into the atmosphere from vegetation, including agricultural crops and natural vegetation. The atmospheric chemistry of a series of monoterpenes and selected reaction products have been investigated. The aldehyde and ketone products from the hydroxyl radical and ozone reactions with (alpha)-pinene, (beta)-pinene, 3-carene, limonene, sabinene, camphene and terpinolene have been identified and quantified. Large volume samples (2000 liters) were collected after reaction for product identification, using mass spectrometry, infrared spectroscopy and proton NMR spectroscopy. These carbonyl compounds accounted for up to 50% of the total reaction products, and efforts are underway to identify the remaining products of these atmospherically-important reactions using in situ atmospheric pressure ionization tandem mass spectrometry. In addition to these product studies, the rate constants for the atmospherically-important reactions of
three of the monoterpene reaction products, nopinone, camphenilone and 4-acetyl-l-methylcyclohexene, have been determined.
Impacts
(N/A)
Publications
- HAKOLA, H., AREY, J., ASCHMANN, S. M. and ATKINSON, R. 1993. Product formation from the gas-phase reactions of OH radicals and O(subscript 3) with a series of monoterpenes. J. Atmos. Chem. (in-press).
- ATKINSON, R. and ASCHMANN, S. M. 1993. Atmospheric chemistry of the monoterpene reaction products nopinone, camphenilone, and 4-acetyl-l-methylcyclohexene. J. Atmos. Chem. 16:337-348.
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Progress 01/01/92 to 12/30/92
Outputs
Non-methane organic compounds are emitted into the atmosphere from vegetation, including agricultural crops and natural vegetation. The emissions from 12 typical shade trees of the Los Angeles air basin were determined early-on in this project. Vegetative emissions can play a role in urban smog formation, as well as in the chemistry of the clean troposphere. In the first six months of this project, the atmospheric chemistry of beta-phellandrene, a monoterpene which is the major emission from tomato plants, was examined. A method was developed to allow sufficient material to be collected and purified from gas-phase reactions conducted in 6000-liter Teflon chambers for absolute product identification. 4-Isopropyl-2-cyclohexen-1-one was identified as a product of the gas-phase reactions of beta-phellandrene with hydroxyl radicals and with ozone, and its formation yields determined. The experimental techniques developed are now being applied to study the ketone and
keto-aldehyde products of several additional monoterpenes.
Impacts
(N/A)
Publications
- CORCHNOY, S. B., AREY, J., and ATKINSON, R. 1992. Hydrocarbon emissions from twelve urban shade trees of the Los Angeles, California, air basin. Atmos. Envion. 26B:339-348.
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