Environ. Sci. Technol. 1993, 27, 2754-2758
Atmospheric Oxidation of Biogenic Hydrocarbons: Reaction of Ozone with &Pinene, D-Limonene and trans-Caryophyllene Daniel GrosJean,’*tEdwln L. Wllllams, II,? Erlc Grosjean,t Jean M. Andino,* and John H. Seinfeld* DGA, Inc., 4526 Telephone Road, Suite 205, Ventura, California 93003, and Department of Chemical Engineering, California
Institute of Technology, Pasadena, California 91 125
Several gas-phase carbonyl products of two terpenes, @-pineneand D-limonene,and of the sesquiterpene, transcaryophyllene, have been identified and their concentrations measured in experiments involving the reaction of these unsaturated biogenic hydrocarbons with ozone in the dark. Cyclohexane was added as a scavenger for the hydroxyl radical to minimize interferences from OH, which forms as a product of the ozone-hydrocarbon reaction. Carbonyl products were formaldehyde (yield = 0.42) and nopinone (yield = 0.22) from @-pinene,formaldehyde (yield = 0.10) and 4-acetyl-1-methylcyclohexenefrom D-limonene, and formaldehyde (yield 0.08) from transcaryophyllene. The nature and yields of these products are discussed in terms of the ozone-olefin reaction mechanism. The ozone-&pinene reaction rate constant, measured in the presence of cyclohexane, is 12.2 f 1.3 X 10-l8 cm3 molecule-’ s-1 at 22 f 1OC. Carbonyl products have also been identified in exploratory experiments with trans-caryophyllene and NO in sunlight. Introduction Biogenic hydrocarbons have for many years received attention for their contribution to the production of ozone and the formation of aerosols in urban and rural areas (1-3). Olefinic biogenic hydrocarbons including isoprene (C5H8),terpenes (CloHd, and sesquiterpenes (C15H24) are known or expected to react with ozone, with the hydroxyl radical, and with the nitrate radical (4, 5 ) . While the atmospheric chemistry of isoprene has been the object of several laboratory studies (6-B), much less is known regarding the reaction products of terpenes (9-12); the oxidation of sesquiterpenes has not been studied. Information on the oxidation products of terpenes and sesquiterpenes under atmospheric conditions is important to elucidate their oxidation mechanisms and to assess their overall reactivity, which is influenced to a large extent by the nature and reactivity of their first-generation carbonyl reaction products. This information is also important as input to computer kinetic models that attempt to describe the atmospheric transformations and fate of biogenic hydrocarbons (13-15). Relevant regulatory issues include the contribution of biogenic hydrocarbons to oxidant formation downwind of urban areas and the role of transported oxidants on air quality a t downwind forested locations including class I wilderness areas (16). We have carried out an experimental investigation of the ozone-biogenic hydrocarbon reaction with a focus on the nature and the yields of carbonyl products. For olefins such as terpenes and sesquiterpenes, daytime removal by reaction with ozone is a major loss process which competes,
* Corresponding author. +DGA, inc. -. California Institute of Technology.
*
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Environ. Sci. Technol., Vol. 27,No. 13, 1993
often favorably, with removal by reaction with the hydroxyl radical (see the Discussion section). Laboratory studies of aerosol formation from olefins including terpenes suggest that much of the aerosol produced is formed in pathways that are initiated by reaction with ozone (17-19). The hydroxyl radical is a product of the reaction of ozone with olefinic biogenic hydrocarbons including isoprene and several terpenes (20). Since OH in turn reacts rapidly with olefins and with their carbonylproducts, the presence of OH complicates the results and their interpretation with respect to ozone-biogenic hydrocarbon reaction mechanisms. Thus, there is a need to investigate the reaction of ozone with terpenes and sesquiterpenes under conditions that minimize “interferences’ due to the hydroxyl radical. We have studied the ozone-biogenic hydrocarbon reaction in the presence of the saturated hydrocarbon cyclohexane, which was added to scavenge the hydroxyl radical (20). This enabled us to obtain information on carbonyl products that could be unambiguously ascribed to the ozone-organic reaction. Our study includes two terpenes, @-pineneand D-limOnene, which are among the most abundant terpenes in ambient air (21-23). Limonene, a monocyclic diolefin, and @-pinene,a bicyclic 1-alkene, are representative of the range of structure and reactivity differences found among terpenes that are relevant to the role of biogenic hydrocarbons in air quality. We have also studied the oxidation of one sesquiterpene, trans-caryophyllene, which is an important biogenic emission from a variety of plant species (24,25). Since to our knowledge the atmospheric chemistry of sesquiterpenes has not been studied, we have also investigated the oxidation of trans-caryophyllene in sunlight irradiations of mixtures of this sesquiterpene with nitric oxide in air. Experimental Methods
Ozone-Organic Reaction in the Dark. The organicozone experiments were carried out at ambient temperature in a 3.5-m3 all-Teflon collapsible chamber constructed from transparent 200A FEP Teflon film (26). The use of Teflon film minimizes reactants and products loss to the chamber walls (27). The matrix air was purified by passing ambient air through large cartridges containing activated carbon, silica gel, molecular sieves, and permanganate-coated alumina. A glass-fiber filter was inserted downstream of the sorbent cartridges to remove particulate matter from the purified airstream, which contained less than 1ppb of reactive hydrocarbons, ozone, NO, and NO2 and less than 0.1 ppb of formaldehyde, acetaldehyde, and other carbonyls. A typical experiment involved the reaction of 0.07-0.10 ppm ozone with 1.0 ppm @-pinene, 1.2 ppm D-limonene, or 0.2-0.5 ppm transcaryophyllene in the presence of 200 ppm cyclohexane in purified air. Ozone was measured by ultraviolet photometry using a calibrated Dasibi 1108continuous analyzer 0013-936X/93/0927-2754$04.00/0
0 1993 American Chemical Society
and was produced using the instrument's built-in ozone generator. Carbonyl reaction products were investigated for all three hydrocarbons. The ozone-hydrocarbon reaction rate constant was measured for one hydrocarbon, 0-pinene, in three experiments carried out a t 22 f 1"C under pseudo-first-order conditions (initial 0-pinenelozone concentration ratios = 12.5-14.3) in the presence of 200 ppm cyclohexane. For these kinetic measurements, ozone concentrations were taken a t 5-min intervals from the continuous concentration-time profiles recorded by the ultraviolet photometer. A control experiment was carried out with only ozone and 200 ppm cyclohexane. The ozone loss rate in this control experiment was 6.4 X lo4 s-' and was identical to that measured for ozone loss to the chamber walls in separate experiments carried out with ozone alone in purified air. Thus, impurities in cyclohexane, if any, did not contribute to ozone removal in the ozone-@-pinene experiments. Reaction of trans-Caryophyllene with NO in Sunlight. Mixtures of trans-caryophyllene (0.5 ppm) and nitric oxide (0.23-0.31 ppm) in purified air were exposed to sunlight in a 3.5-m3 Teflon chamber. Ozone was measured as described above. Oxides of nitrogen were measured by chemiluminescence using a Monitor Labs 8840 continuous analyzer calibrated using the diluted outputs of a certified NO standard (3600 ppm in Nz) and of a certified NO2 permeation tube maintained a t 30.0 f 0.1 oc. Carbonyl Products. Carbonyl products were isolated as their 2,4-dinitrophenyl hydrazones by sampling the reaction mixture through small CIS cartridges coated with twice recrystallized 2,4-dinitrophenylhydrazine(DNPH) as described previously (28, 29). In order to minimize possible reactions between DNPH and/or hydrazones and ozone present in the chamber, the CIScartridge samples collected in the ozone-biogenic hydrocarbon experiments were taken after all the ozone had been consumed. The sampling flow rate was 0.8 L/min, and the sampling duration was 60-90 min. Following collection, the cartridges were eluted with HPLC-grade acetonitrile, and aliquots of the acetonitrile extracts were analyzed by liquid chromatography with ultraviolet detection. The DNPH derivatives were separated on a Whatman Partisphere CIS column, 110 X 4.7 mm, with 55:45, by volume, CH3CNHzO eluent at a flow rate of 1 mL/min. The detection wavelength was 360 nm. The liquid chromatograph components included a solvent delivery system equipped with 0.2-rm pore size Teflon filters, a SSI 300 pump, a 20-pL injection loop, a Whatman Partisphere CIS guard cartridge, and a Perkin Elmer LC75 UV-visible detector. More details regarding the sampling and analytical protocols have been given elsewhere (28, 29). Quantitative analysis involved the use of external hydrazone standards, from which calibration curves, Le., absorbance (peak height) vs concentration, were constructed. Confirmation of the structure of the carbonyl DNPH derivatives was obtained by recording their UVvisible spectra, as dilute solutions in the CH~CN-HZO eluent, using a diode array detector (28) or by measuring the 430:360 nm absorbance ratio as a test for dicarbonyls (29). Positive identification could be made by matching retention times and absorbance ratios of sample peaks to those of reference standards, for which structure confirmation had been obtained independently by chemical ionization mass spectrometry (30).
Table I. Summary of Experimental Conditions and Initial Concentrations Ozone-Organic Reaction in the Dark run cyclohexanea olefin ozone olefin no. (PPd (ppm) (ppb) D-limonene
200 200 200 200 200 0 200
1 2 1 2 3 1 2
&pinene trans-caryophyllene
1.2 1.2
1.0 1.0 1.0 0.18 0.54
100 70 75 80 70 70 80
Organic-NO Sunlight Irradiations NO-NO2 crossover run olefin NO elapsed no. (ppm) (ppb) (ppb) time (mid
olefin
trans-caryophyllene
1 2
0.47 0.54
315 230
82 13b
210 260
a Added to scavenge OH, see text. b Crossover concentration reflects a 10-fold dilution with Durified air after 3 h in sunlight.
The terpenes D-limonene and 0-pinene (Aldrich Chemical Co.), the sesquiterpene trans-caryophyllene (Fluka), (Aldrich) and the carbonyls 4-acetyl-1-methylcyclohexene and 6,6-dimethylbicycl0[3.1.1]heptan-2-one (Aldrich, hereafter called nopinone) had stated purities of 95-99% and were used without further purification. The DNPH derivatives of nopinone and of 4-acetyl-1-methylcyclohexene were synthesized by reaction of the carbonyl with DNPH (12). Their 200-600-nm spectra were recorded (not shown) and exhibited absorption maxima a t 372 and 370 nm, respectively, consistent with data for DNPH derivatives of other aliphatic monofunctional carbonyls (28,291. The base peak (most abundant fragment) in their methane CI mass spectra was 319 (MW = 318 for both compounds). Less abundant fragments (abundance = 1020% of that of the base peak) of diagnostic value (30) included those at mass/charge ratios of 320 (13C isotopic contribution to base peak), 349 (M + 29 reagent gas adduct) and 289 (M 1-30, probably loss of NO). For these and other carbonyl DNPH derivatives, liquid chromatography calibration curves were constructed in the concentration range that bracketed those found in the DNPH cartridge samples collected in the hydrocarbon-ozone and sesquiterpene-NO-sunlight experiments.
+
Results and Discussion Initial concentrations and experimental conditions are listed in Table I. Carbonyl products, their concentrations and yields are listed in Table 11. Listed in Table I11 are unidentified carbonyls whose retention and/or absorbance parameters did not match those of some 35 carbonyl DNPH derivatives synthesized and characterized in our laboratory (8, 12,29, 30). Cyclohexane as a Scavenger for OH in OzoneOrganic Experiments. An upper limit for the extent of reaction of OH with the biogenic hydrocarbon in the presence of excess cyclohexane can be estimated from the corresponding OH reaction rate constants and the initial concentrations of the unsaturated hydrocarbons relative to that of cyclohexane. Rate constants for the reaction of OH with cyclohexane, @-pinene,and D-limonene are 7.5 X 10-l2, 79 X 10-l2, and 170 X cm3 molecule-' 5-1, respectively (31). Structure-reactivity considerations (17.1 Environ. Scl. Technol., Vol. 27, No. 13, 1993 2755
_-
__.
--
Table 11. Carbonyl Products of Ozone-Biogenic Hydrocarbon Reaction with Excess Cyclohexane to Scavenge OH --
concentration (ppb)
-
20
-- 1 0
carbonyl 8-pinene
formaldehyde acetme nopinone cycloh~xanor~$d
3=
1'
2c
3c
4c
5c
6c
average yieldb
23 6 13
26
19
23
0.42
5
4
1
16
14
23 2 15 7
20
8
14
15 6
6
5
0.22
0.11 formaldehyde 9 9 8 6 0.10 4 ~ a c e ~ y ~ - l ~ ~ ~ ~ h y ~ - c y c ~ o h 2e x e n e 1 1 2 0.0P cyclohexanoned 12 12 8 9 0.12 trans-caryophyllene formaldehyde 6 8 2 2 0.8 cyclohexanone 1 2 1 1 10.02 Experiment number. Calculated as ppb carbonyl formedippb ozone reacted, i.e., assuming a 1:l stoichiometry for the ozone--olefin reaction. Sample number. Product of the OH-cyclohexane reaction, see text. e Not corrected for reaction of this unsaturated carbonyl product with ozone. see text, 8
8
D-limonene
"_
___I_^
l_l_lll__
1.6~---
Table 111. Unidentified Carbonyl Products unknown carbonyl type of experiment retention peak 430:360 ozone, ozone C NO, timeo heighta nrn ratio dark NO*, dark sunlight
l l _ ^ _ _ l _
8-pinene trans-caryophyllene
2.5 2.6 8.6 21
2.4 5.0 17.5
~
0.04-0.06
0.054.:
0.05 0.02 0.014.05
0.05
0.05
cO.1 0.33
0.25 e0.1
+* f -
-
+
0.2
f
-
I
-5
"+
-44-
+ +
Relative to that of formaldehyde. (+) observed; (-) not present.
ti a
0 suggest that trans-caryophyllene, for which no kinetic data c) are available, may react with OH a t a rate similar to that of limonene. With initial cyclohexane/biogenic hydrocarbon concentration ratios of 167 (u-limonene), 200 (0pinene), and 370 and 1100 (trans-caryophyllene), the reaction rate constants given above indicate that only a small fraction of the OH formed in the biogenic hydrocarbon-ozone reaction, 5 5 % for 0-pinene, 5 1 2 % for D-limonene, and 52-63 ?Z for trans-caryophyllene, is not consumed by its reaction with cyclohexane under the conditions of our study. Ozone-&Pinene Reaction Rate Constant. As is 0.0 i---0 1000 2000 3000 4000 5 shown in Figure 1, scatter plots of In C0310/[03It vs time, where LO310 is the initial ozone concentration and [ 0 3 1 t is Time. sec the ozone concentration at time t, were linear. Leastsquares regression analysis of the data yielded near-zero Flgure 1. Scatter plots of In [03]o/[03]t vs time in three ozone-/?intercepts (1.9-3.8 X lW,correlation coefficients > 0.997, pinene-cyclohexane experiments. and slopes of 2.96 X IO4, 3.01 X IO4, and 3.08 X 10"' s-I with relative standard deviations of 1.3-2,3 %. After a Qzsne Reaction: General Considerations. The 2% correction for the measured loss of ozone to the reaction of ozone with the three biogenic hydrocarbons chamber walls, these slopes yielded ozone-0-pinene restudied is expected to involve, by analogy with other action rate constants of 12.0 x 10-l8, 12.2 x and 12.5 olefins, electrophilic addition on the unsaturated carbonx 10-18 cm3 molecule-1 s-l at 22 f 1 "C. carbon bond followed by decomposition of the 1,2,3The average of these values is 12.2 f 1.3 X 10-l8 ~ m - ~trioxolane adduct into two carbonyls and two Criegee molecule-1 s-l, where the stated uncertainty is dominated biradicals: by the uncertainty in the initial @-pineneconcentration, R,R,C = CR3R, + 0, R,COR, + R,R,COO (la) This reaction rate constant is lower than those obtained in three earlier studies, i.e., 21 x lO-lS, 38 X 10-ls, and 65 + R,COR, + R,R,COO (lb) x 10-18 cm3 molecule-' s-l (see refs 31 and 32 for a review Subsequent reactions of the Criegee biradicals are of these earlier studies) and compares well with data from uncertain at the present time. Recent studies of the two recent studies: Le., in units of cm-3 molecule-' reaction of ozone with trans-2-butene, 2-methyl-2-butene, s-1,14 f 2 measured using a relative rate method (33)and and 2,3-dimethyl-2-butene (26, 34-36), of the carbonyl 16.7 i 2.0 also measured using a relative rate method (32) products of the reaction of ozone with a number of simple and 14.8 f 1.7 derived, as in this work, from absolute rate alkenes ( 3 3 ,and of the OH yield in the reaction of ozone measurements (32). 6
-
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Environ. Sci. Tachnol., Vol. 27, No. 43, 1993
+
with a number of alkenes and terpenes (20,38) provide supporting evidence for the following reaction pathways (37):
R,R,COO
-- ++
0,
@
+
HCHO
R,C(O)OR, (ester or carboxylic acid when R, = H) (2)
0
-
R,COR,
OH
R,CO
(3)
(when R, = H)
CH, = C(R,)OOH
(4)
(when R, = CH,) ( 5 )
,CH3
The hydroperoxide formed in reaction 5 evolves via an hydroxycarbonyl intermediate as follows: CH, = C(R)OOH
--
-
(CH,OHC(O)R*) CH,OHC(O)R (hydroxycarbonyl) (6) H,
+ HCOC(0)R (dicarbonyl)
- -
H
(7)
OH + RCOCH, (8) CH,OH + RCO (unimolecular decomposition) (9) followed by CH20H 02 formaldehyde + HOz and RCOCH, + 02 peroxy radical. Reactions 2-9 can be used as a guide to discuss the reaction products of the biradicals formed in the reaction of ozone with @-pinene,D-limonene, and trans-caryophyllene. In the presence of cyclohexane, the OH radical formed in reactions 4 and/or 8 leads to cyclohexanol and cyclohexanone (20, 38, 39). Indeed, we observed cyclohexanone as a reaction product, thus indicating that OH was formed in the reaction of ozone with the terpenes @-pineneand D-limonene as previously observed (20) and also in the reaction of ozone with the sesquiterpene transcaryophyllene. B-Pinene-Ozone Reaction. Carbonyls identified as products of the ozone-@-pinene reaction included formaldehyde and nopinone along with small amounts of acetone (probably present as an impurity or as a product of the reaction of ozone with an olefinic impurity). Also present in small amounts were three unidentified carbonyls, two aliphatic carbonyls with short retention times and one higher molecular weight carbonyl that eluted after nopinone. The formaldehyde and nopinone yields averaged 0.42 and 0.22, respectively. Some of the nopinone may be present as a component of the aerosol (10). Our formaldehyde and nopinone yields are lower than those previously reported for the @-pinene-ozonereaction studied without OH scavenger (18). This is not unexpected since both carbonyls are also products of the OH-@-pinene reaction (9, 11, 12). D-Limonene-Ozone Reaction. Carbonyl products of the ozone-D-limonene reaction included formaldehyde and smaller amounts of 4-acetyl-1-methylcyclohexene.The reaction of D-limonene with ozone involves ozone addition on two unsaturated carbon-carbon bonds. While the more substituted internal C=C bond is presumably more reactive than the terminal C=C bond, the carbonyl products we observed are those consistent with ozone addition on the terminal bond, and the formaldehyde yield indicates that ozone adds on the terminal bond a t least 10% of the time. Ozone addition on the internal C=C bond leads to two biradicals, one monosubstituted and the other disubstituted. No carbonyl products are directly
+
c C COO = O
PRODUCTS INCLUDING
fl\
HC
C CH3
II
II
0
0
m C OH
CH3C II
II
0
0
AND OTHER PRODUCTS
Figure 2. Tentative mechanism for the ozone-trans-caryophyiiene reaction: addition of ozone on the external (A) and internalunsaturated carbon-carbon bonds (B, structure simplified for clarity).
formed by the addition of ozone on the internal C=C bond. The biradicals formed in the ozone-D-limonene reactions are expected to evolve into a number of C9 and CIO polyfunctional oxygenates, see reactions 2-9. Some of these products are expected to have low vapor pressures and to accumulate as an aerosol (40, 41). Indeed, measurements of the total particulate carbon formed in the D-limonene-ozone experiments (41) indicate that aerosol products account for 22% of the reacted D-limonene. The unsaturated carbonyl product 4-acetyl-lmethylcyclohexene also reacts with ozone (42))leading to two biradicals (no carbonyl products are directly formed) whose reactions may also lead to low-volatility Cg and Clo polyfunctional oxygenated products. trans-Caryophyllene-Ozone Reaction. The only carbonyl positively identified as a product of the ozonetrans-caryophyllene reaction was formaldehyde. Formaldehyde is formed by the addition of ozone on the terminal C=C bond, which is presumably less reactive than the more substituted internal C=C bond (hence, the low formaldehyde yield of 0.08). Expected to form along with formaldehyde is an unsaturated C14 ketone, MW = 206. This unsaturated ketone, which is expected to be consumed by reaction with ozone, was tentatively observed by chemical ionization mass spectrometry analysis (singleion monitoring a t 387 amu, MW of ketone-DNPH derivative = 386). Addition of ozone on the internal C=C bond does not lead directly to carbonyl products. The reaction pathways shown in Figure 2 lead to high molecular weight, lowvolatility polyfunctional oxygenates, a number of which may accumulate as aerosol (17,18,41). Measurements of particulate carbon in trans-caryophyllene-ozone experiments (41)indicate that aerosol products account for 12 % of the reacted sesquiterpene. Environ. Scl. Technol., Vol. 27, No. 13, 1993 2757
Sunlight Irradiation of trans-Caryophyllene-NO Mixtures. Formaldehyde (13-18 ppb) was observed to form upon sunlight irradiations of mixtures of NO and trans-caryophyllene, along with small amounts of glyoxal (1-3 ppb), methylglyoxal(1-4 ppb), and four unidentified carbonyls whose retention and absorbance parameters are listed in Table 111. The carbonyl samples were collected before the NO-NO2 crossover (no ozone present in the system), Le., when the oxidation of trans-caryophyllene is dominated by its reaction with the hydroxyl radical. The OH reaction pathways relevant to formaldehyde production involve OH addition on the terminal C=C bond followed, for the two @-hydroxyalkylradicalsformed, by the sequence R + 0 2 RO2 and RO2 + NO NO2 + RO. For these P-hydroxyalkoxy radicals, unimolecular decomposition presumably dominates over reaction with oxygen (43),thus leading to formaldehyde and to the same C14ketone as that discussed in the preceding section (this ketone is also a product of the ozone reaction). This C14 ketone was tentatively observed by CI-MS. Addition of OH on the internal C=C bond involves similar pathways and leads to the formation of C14 and other high molecular weight oxygenates, some of which may accumulate in the aerosol phase (41).
-
-
Acknowledgments Dr. John B. Palmer of Southern California Edison Co., Rosemead, CA, provided technical advice. Ms. Denise M. Velez prepared the draft and final versions of the manuscript. This work has been sponsored by Contract C-3052907 with the Southern California Edison Co. (SCE), Rosemead, CA, and by National Science Foundation Grant ATM-9003186. Literature Cited (1) Rasmussen, R. A. J . Air Pollut. Control Assoc. 1972, 22, 537-543. (2) Lamb, B.; Guenther, A.; Gay, D.;Westberg, H. Atmos. Environ. 1987, 21, 1695-1705. (3) Chameides, W. L.; Lindsay, R. W.; Richardson, J.; Kiang, C. S. Science 1988,241, 1473-1475. (4) Atkinson, R. J. Phys. Chem. Ref. Data 1991,20,459-507. (5) Wayne, R. P.; et al. Atmos. Environ. 1991,25A, 1-206. (6) Tuazon, E. C.; Atkinson, R. Int. J. Chem. Kinet. 1990,22, 1221-1236. (7) Paulson, S. E.; Flagan, R. C.; Seinfeld, J. H. Int. J . Chem. Kinet. 1992,24, 79-101. ( 8 ) Grosjean, D.;Williams, E. L., 11;Grosjean, E. Environ. Sci. Technol. 1993,27, 830-840. (9) Hatakeyama, S.; Izumi, K.; Fukuyama, T.; Akimoto, H.; Washida, N. J . Geophys. Res. 1991,96, 947-958. (10) Yokouchi, Y.; Ambe, Y. Atmos. Environ. 1985, 19, 12711276. (11) Arey, J.; Atkinson, R.; Aschmann, S. M. J. Geophys. Res. 1990, 95, 18539-18546. (12) Grosjean, D.;Williams, E. L., 11; Seinfeld, J. H. Environ. Sci. Technol. 1992, 26, 1526-1533.
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(13) Paulson, S. E.; Seinfeld, J. H. J. Geophys. Res. 1992, 97, 20703-20716. (14) Atherton, C. S.; Penner, J. E. J . Geophys. Res. 1990, 95, 14027-14038. (15) Hov, 0.; Schjoldager, J.; Wathne, B. M. J. Geophys. Res. 1983,88, 10679-10688. (16) Smith, W. H, Chem. Eng. News 1991, Nou 11, 30-33. (17) Grosjean,D.; Seinfeld,J. H. Atm'os.Environ. 1989,23,16011606. (18) Hatakeyama, S.; Izumi, K.; Fukuyama, T.; Akimoto, H. J. Geophys. Res. 1989, 94, 13013-13024. (19) Pandis, S. N.; Paulson, S. E.; Seinfeld, J. H.; Flagan, R. C. Atmos. Enuiron. 1991,25A, 997-1008. (20) Atkinson, R.; Aschmann, S. M.; Arey, J.; Shorees, B. J. Geophys. Res. 1992,97, 6065-6073. (21) Graedel, T. E. Rev. Geophys. Space Phys. 1979, 17, 937947. (22) Roberts, J. M.; Fehsenfeld, F. C.; Albritton, D. L.; Sievers, R. E. J. Geophys. Res. 1983,88, 10667-10678. (23) Petersson, G. Atmos. Environ. 1988, 22, 2617-2619. (24) Arey, J.;Winer,A. M.;Atkinson, R.;Aschmann,S. M.; Long, W. D.; Morrison, C. L.; Olszyk, D.M. J . Geophys.Res. 1991, 96,9329-9336. (25) Winer,A. M.;Arey,J.;Atkinson,R.;Aschmann,S. M.;Long, W. D.;Morrison, C. L.; Olszyk, D.M. Atmos. Environ. 1992, 26A, 2647-2659. (26) Grosjean, D. Environ. Sci. Technol. 1990, 24, 1428-1432. (27) Grosjean, D.Enuiron. Sci. Technol. 1985, 19, 1059-1065. (28) Druzik, C. M.; Grosjean, D.;Van Neste, A.; Parmar, S. S. Int. J. Environ. Anal. Chem. 1990,38,495-512. (29) Grosjean, D.Environ. Sci. Technol. 1991, 25, 710-715. (30) Grosjean, D.Anal. Chem. 1983,55, 2436-2439. (31) Atkinson, R. Atmos. Environ. 1990, 24A, 1-41. (32) Atkinson, R.; Hasegawa, D.;Aschmann, S. M. Int. J . Chem. Kinet. 1990,22, 871-887. (33) Nolting, F.; Behnke, W.; Zetzsch, C. J. Atmos. Chem. 1988, 6, 47-59. (34) Martinez, R. I.; Herron, J. T. J . Phys. Chem. 1987,91,946953. (35) Martinez, R. I.; Herron, J. T. J. Phys. Chem. 1988,92,46444648. (36) Niki, H.; Maker, P. D.;Savage, C. M.; Breitenbach, L. P.; Hurley, M. D.J. Phys. Chem. 1987,91,941-946. (37) Grosjean, D.; Grosjean, E.; Williams, E. L., 11.Environ. Sci.
Technol., in press.
(38) Atkinson, R.; Aschmann, S. M. Environ. Sci. Technol. 1993, 27, 1357-1363. (39) Tagaki, H.; Washida, N.; Bandow, H.; Akimoto, H.; Okuda, M. J . Phys. Chem. 1981,85, 2701-2705. (40) Schueltze,D.;Rasmussen,R. A. J.AirPollut. Control Assoc. 1986,28, 236-240. (41) Grosjean, D.;Williams, E. L., 11; Grosjean, E.; Novakov, T.
Evolved gas analysisof secondary organic aerosols. Aerosol Sci. Technol., in press. (42) Atkinson, R.; Aschmann, S. M. J. Atmos. Chem. 1993,16,
337-347. (43) Atkinson, R.; Carter, W. P. L. J. Atmos. Chem. 1991, 13, 195-210.
Received for review February 8, 1993. Revised manuscript received September 7, 1993. Accepted September 8,1993." ~~~
0
AbstractpublishedinAdvance ACSAbstracts,October 15,1993.
