Environ. Sci. Technol. 1969, 23, 679-687
prepared under EPA Contract No. 68-02-4251, dated June 4,1987.
Seber, G. A. F. Multivariate Observations; Wiley: New York, 1984. Kier, L. B.; Hall, L. H. Molecular Connectivity in Chemistry and Drug Research;Academic Press: New York, 1976. SabljiE,A.; TrinajstiE, N. Acta Pharm. Jugal. 1981,31,189. TrinajstiE, N. Chemical Graph Theory; CRC Press: Boca Raton, FL, 1983. Howard, P. H.; Hueber, A. E.; Boethling, R. S. Environ. Toxicol. Chem. 1987,6, 1. Spain,J. C.; Van Veld, P. A. Appl. Environ. Microbiol. 1983, 45,428. Spain, J. C.; Pritchard, P. H.; Bourquin, A. W. Appl. Environ. Microbiol. 1980,40,726. Spain, J. C.; Van Veld, P. A.; Monti, C. A,; Pritchard, P. H.; Cripe, C. A. Appl. Environ. Microbiol. 1984,48,944. Lee, R. F.; Ryan, C. In Proceedings of the Workshop: Microbial Degradation of Pollutants in Marine Environments; Bourquin, A. W., Pritchard, P. H., Eds.; U.S.Environmental Protection Agency: Gulf Breeze, FL, 1979;pp 443-450, EPA-600/9-79-012. Pritchard, P. H.; O'Neill, E. J.; Spain, C. M.; Ahearn, D. G. Appl. Enuiron. Microbiol. 1987,53, 1833.
(12) Johnson, B. T.;Heitkamp, M. A.; Jones, J. R. Environ. Pollut., Ser. B 1984,8,101. (13) Heitkamp, M.A,; Cerniglia, C. E. Environ. Toxicol. Chem. 1987,6,535. (14) Hambrick, G. A., III; DeLaune, R. D.; Patrick, W. H., Jr. Appl. Environ. Microbiol. 1980,40,365. (15) Heitkamp,M. A.; Huckins, J. N.; Petty, J. D.; Johnson, J. L.Environ. Sei. Technol. 1984,18, 434. (16) Heitkamp, M. A.; Freeman, J. P.; Cerniglia, C. E. Appl. Environ. Microbiol. 1986,51,316. (17) Wang, Y.-S.; Madsen, E. L.; Alexander, M.J. Agric. Food Chem. 1985,33,495. (18) Toplias, J. G.; Edwards, R. P. J. Med. Chem. 1979,22,1238. (19) Boethling, R. S. Environ. Toxicol. Chem. 1986, 5, 797. (20) Sugatt,R. H.; OGrady, D. P.; Banerjee, S.; Howard, P. H.; Gledhill, W. E. Appl. Environ. Microbiol. 1984,47,601. (21) Kier, L. B. J. Pharm. Sei. 1980,69,1034. (22) Kier, L. B.; Hall, L. H. Molecular Connectivity in Structure-Activity Analysis; Research Studies Press: Letchworth, Hertfordshire, England, 1986. (23) SabljiE, A. Environ. Sei. Technol. 1987,21, 358.
Received for review April 4,1988. Revised manuscript received September 2, 1988. Accepted December 28, 1988.
Chemical Compositlon of Environmental Tobacco Smoke. 1 Gas-Phase Acids and Bases a
Deiberl J. Eatough,' Cynthia L. Benner,+ Jose M. Bayona,$Galen Richards, John D. Lamb, Milton L. Lee, Edwln A. Lewis, and Lee D. Hansen
Department of Chemistry, Brigham Young University, Provo, Utah 84602
w This paper describes the chemical characterization of gas-phase components of environmental tobacco smoke generated in 10-and 30-m3Teflon chambers. Gas-phase acids and bases in environmental tobacco smoke were determined by using several different diffusion denuder samplers with the collected compounds being analyzed by ion chromatography, gas chromatography, or gas chromatography-mass spectrometry. The results indicate that the major inorganic acid present in the gas phase of environmental tobacco smoke is HNOP Principal gas-phase bases present are NH3, nicotine, pyridine, 3-ethenylpyridine, and myosmine. Based on the environmental chamber experiments performed to date, five potential gas-phase tracers of environmental tobacco smoke have been identified: nicotine, 3-ethenylpyridine, pyridine, myosmine, and HN02. Introduction
The prevalence of exposure to environmental tobacco smoke (ETS)in indoor environments ( 1 , 2 )and the suspected development of several health problems associated with this exposure (3-8) have contributed to the need to develop better methods for evaluating exposure to environmental tobacco smoke. The reliability of current estimates of the health effects associated with exposure to environmental tobacco smoke ( 2 , 3 , 6 , 9 )is limited by the accuracy of the dose estimates. Tracers of environmental tobacco smoke used in the past include the following: respirable or total suspended particulate matter (9-1 1 ) ; 'Present address: ADA Technolgies, Inc., Englewood,CO 80112.
* Present address: CID-CSIC,Environmental Chemistry Dept.,
08034 Barcelona, Spain.
0013-936X/89/0923-0679$01.50/0
CO (12, 13);nicotine (14-20); urinary concentrations of nicotine and cotinine (21-25); frequency of smoking (26-28). Frequency of smoking is not a quantitative measure of actual exposure to environmental tobacco smoke (6,29). Both particulate matter and CO are not unique tracers, since there are many other sources (6,14, 30,31). Concentrations of other nonspecific tracers such as NO, and PAH are also poor tracers of the contribution of environmental tobacco smoke to pollution in an indoor environment (6, 14). Nicotine is a compound unique to and a major constituent of environmental tobacco smoke. Indeed, more nicotine is emitted per cigarette with sidestream smoke than is present in mainstream tobacco smoke (32-34). The indoor environment where smoking is present contains sufficient nicotine to be detected by a variety of methods (14-18,20,26). However, the majority of the nicotine in environmental tobacco smoke is present in the gas phase (14,15,17,18,35,36).Many other compounds in tobacco smoke condensate may also be present in the gas phase or distributed between the gas and particulate phases in environmental tobacco smoke. The shift of a compound from the particulate phase in tobacco smoke condensate to the gas phase in environmental tobacco smoke would be expected to affect the chemistry, toxicology, and deposition of environmental tobacco smoke as compared to mainstream tobacco smoke. Such shifts in phase equilibria of certain compounds, for example, may explain observed mutagenicity differences between sidestream and mainstream tobacco smoke (37,38)and the mutagenicity of the gas phase of environmental tobacco smoke (39). The sampling of a compound that may be present in both the gas and particulate phases is a difficult analytical problem, since collection of particles may result in the
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subsequent loss of semivolatile compounds as the composition of the air surrounding the particles changes. If gas-phase compounds are collected after removal of particles on a fiiter, the gas-phase compounds and compounds volatilized from the particles during sampling become indistinguishable. However, gas-phase compounds can be selectively collected from the atmosphere by using a diffusion denuder with an appropriate collection surface. Thus, gas-phase acids can be collected with a diffusion denuder with a basic surface (40), and bases can be collected with a diffusion denuder with an acidic surface (14, 15,36). This paper presents results obtained with diffusion denuder samplers to collect gas-phase acids and bases separately from particulate-phase acids and bases present in environmental tobacco smoke. The identification of particulate phase species present in environmental tobacco smoke is described in another paper (41).
Experimental Section The initial experiments involved sampling environmental tobacco smoke from a 10-m3unventilated environmental chamber (36). After the completion of these initial scoping experiments, a 30-m3unventilated chamber was constructed and used for all subsequent chamber experiments. Both environmental chambers consisted of Teflon bags with Teflon sampling manifolds at the bottom of the bag. The bag was cleaned prior to an experiment by adding ozone, irradiating the bag with UV light, and finally flushing extensively with clean air from an Aadco Pure Air Generator (Model 737, Aadco, Inc., Rockville, MD). The bag is collapsible so that flushing is done by repeatedly emptying and refilling the bag with clean air. Before beginning an experiment in the environmental chamber, the air quality in the chamber is checked to assure the background is negligible compared to the ETS to be produced by measuring nitrogen oxides (Model 8840 nitrogen oxides analyzer, Monitor Labs, San Diego, CA), ozone (Model 8002 ozone analyzer, Bendix Corp., Lewisburg, WV), CO (Monitor Labs Model 8310 CO analyzer), and particles (TSI Model 3071 Differential Mobility Size Classifier with a Model 3020 Condensation Nucleus Counter; TSI Model 5000 Piezobalance, TSI, Inc., St. Paul, M N Climet Model CI-8060 optical particle counter, Climet Instrument Co., Redlands, CA). All instrumental measurements were collected by a Modular Data Acquisition System (MDAS) Model 7000 (Transera Corp., Provo, UT) and then transferred to an IBM X T personal computer for storage in a Bernoulli box. After approximately 30 min of background data collection, a single cigarette (1R1 Kentucky Reference cigarette, University of Kentucky) in the 10-m3chamber or one to four cigarettes in the 30-m3 chamber were lit electrically and burned with either a standard smoking cycle of one 2-9, 35-cm3 puff every minute or a 10-s initial puff followed by seven 2-s puffs at l-min intervals. The mainstream smoke was withdrawn from the chamber while the sidestream smoke was allowed to freely mix in the chamber. The cigarette(s) was(were) extinguished with H20 at the end of the 5- to 7-min combustion period. The chamber air was mixed with a Teflon-coated stirrer at 50 rpm for either 1 min after the completion of the smoking cycle or for the duration of the 8-min smoking cycle and then allowed to equilibrate without mixing for 15 min. No significant differences in the concentnrations of the various species measured were seen for these two different methods of initially mixing the chamber air. Continual mixing, as expected, resulted in an increased rate of loss of particles due to deposition on the chamber walls. Samples of the atmosphere in the environmental chamber were then obtained
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by sampling with cylindrical and/or annular diffusion denuder systems for 1 4 h. Flow rates were controlled with Tylan mass flow controllers (Tylan Corp., Carson, CA) calibrated against certified Kurz mass flow meters (Kurz Instruments Inc., Carmel Valley, CA) and a dry gas meter (Rockwell Int., Pittsburg, PA). Instrumental measurements were continuously collected during an experiment. A total hydrocarbon analyzer (Bendix Model 8401) was used in some experiments to monitor changes in the concentration of gas-phase organic compounds. Preparation of Diffusion Denuders. Cylindrical diffusion denuders were prepared from 10 cm long sections of glass tubing with an inside diameter of 0.56 f 0.01 cm. The inside wall of the tubing was first etched with concentrated HF and then thoroughly rinsed with H20. For the collection of gas-phase organic bases, the inside wall was coated with 0.8 M benzenesulfonic acid solution, drained, and dried with an N2 stream. Six sections of the coated tubing were combined in series to provide a complete cylindrical diffusion denuder. Annular diffusion denuders (General Flow Co., Milan, Italy) were also prepared for the collection of nicotine and other gas-phase organic bases by coating the annular space of the diffusion denuder with 0.8 M benzenesulfonic acid solution. The diffusion denuder was then drained and dried with an N2stream. Two or three sections of annular denuders were used to check for complete collection of gas-phase compounds by the denuder surface. The annular denuder sections were 20 cm long, with an inside diameter of 3.18 cm and a 0.13-cm annular space (42). For the measurement of inorganic and organic acids, annular denuders were coated with a solution of l % (wt/wt) NaHC03/glycerine, and to trap inorganic bases, annular denuders were coated with a 5 wt % oxalic acid solution. Experiments with Gas-Phase Nicotine. The diffusion denuder systems were used to collect nicotine from prepared gaseous samples. The vapor pressure of nicotine is 28 ppm at 25 "C (43). Pure gas-phase nicotine was generated by passing Nz at a flow rate of 0.5 standard L/min (slpm) over nicotine (Aldrich Chemical Co., Milwaukee, WI) to sweep the vapors in equilibrium with the liquid. This air stream was then passed through a quartz fiiter to remove any particles present and mixed with clean air flowing through a 4-L equilibration chamber at a rate of 40 slpm to give an expected concentration of nicotine in the equilibration chamber of -0.3 ppm (10 pmol/m3). After allowing -30 min for the chamber contents to achieve dynamic equilibrium, samples were collected with the cylindrical and annular diffusion denuders directly from the equilibration chamber at flow rates of 1.5 and 5 slpm, respectively. Any nicotine passing, the diffusion denuder was collected by either two XAD-I1 (Rohm & Haas, Philadelphia, PA) sorbent beds, two Nafion bead (Aldrich) sorbent beds, or two to three sorbent filters (Schleicher & Schuell Fast Flow filter papers, Schleicher & Schuell, Inc., Keene, NH). The XAD-I1 was prepared by sequential Soxhlet extraction with H20, CH30H, and CH2C12. The Nafion beads were washed with 0.1 M HC1, rinsed with HzO, and dried. The sorbent filters were prepared by washing the filters in 0.1 M HC1 at 50 "C, extensively rinsing the filters with HzO,wetting the cleaned filters with 0.8 M benzenesulfonic acid, and air-drying the resulting filters. The diffusion denuders were prepared as described above. Collection of Nicotine and Other Basic Organic Compounds in Environmental Tobacco Smoke. A major objective of this program is to determine the gas/ particle distribution of nicotine and other basic compounds
in environmental tobacco smoke. This has been accomplished by using benzenesulfonic acid (BSA) coated cylindrical or annular diffusion denuders to collect the gasphase nicotine and other basic compounds, followed by a Teflon (Gelman Sciences, Inc., Ann Arbor, MI) or quartz filter to collect particulate-phase compounds and two BSA-coated fast-flow sorbent filters to trap the volatile material evolved from the particles. Cylindrical BSA denuders were used in experiments in the 10-m3chamber to determine the efficiency of BSA for quantitatively collecting gas-phase nicotine in the presence of particles. In the same experiment, samples of nicotine were also obtained with a filter pack consisting of a Teflon filter followed by two BSA-saturated filters. The flow rate through the cylindrical denuders and the filter pack was 2 slpm. In most experiments, two BSA-coated annular denuder sections were used to sample the basic organic compounds. Flow rates through the annular denuder systems were between 5 and 25 slpm. Following sample collection, the annular denuder and cylindrical denuder sections were extracted with 5 mL of distilled H 2 0 and the extract was refrigerated until analyzed. Filters were placed in glass vials and stored at -80 "C until analyzed. The concentration of gas-phase organic bases may also be determined by using a passive sampling device (PSD). A passive nicotine sampler would be preferable over the denuder sampling system in an indoor environment because of the unobtrusive nature of the PSD. A PSD can also serve as a personal monitor for environmental tobacco smoke since it can be worn by an individual. Eight experiments were performed to compare gas-phase organic base concentrations obtained with both BSA-coated annular denuders and two or three of the EPA passive samplers (Scientific Instrumentation Specialists, Moscow, ID), which contained a 22-mm glass fiber filter saturated with 0.8 M BSA. These passive samplers have been characterized by Lewis et al. (44). After sampling, the passive BSA filters were extracted with 4 mL of distilled HzO in an ultrasonic bath for 20 min and analyzed by procedures described below. Determination of Nicotine and Other Basic Organic Compounds. Nicotine in the collected samples was determined both by gas chromatography (GC) and by ion chromatography (IC). The gas chromatographic (Hewlett-Packard Model 5890, Hewlett-Packard Corp., Avondale, PA) determination of nicotine and other basic organic compounds was done with two different capillary columns (SE-33,14.5 m with 0.76 pm df; and SB-methyl-100,lO m with 0.25 pm df), a flame ionization detector (FID) or nitrogen-phosphorus detector (NPD), and an H P Model 3391A integrator. Standard samples of most compounds were prepared by weight in CH2C12to obtain an area vs concentration calibration curve. To analyze the aqueous extracts by GC, a 2-mL aliquot of the solution was shaken in a separatory funnel with 0.5 mL of 0.24 M NaOH and 4 mL of CH2C12for 2 min. The NaOH was added to neutralize the BSA. A l-3-pL sample of the weighed CH2C12solution was analyzed by using the following temperature program (injector temperature, 250 "C; detector temperature, 350 "C; splitless injection): a. initial temperature, 40 "C; b. initial time, 2.0 min; c. program rate, 5-10 "C/min; d. final temperature, 130-165 "C; e. final time, 14-20 min. At the conclusion of this program, the oven was heated at a rate of 25 "C/min and held at 250 "C for 5 min in order to elute additional compounds that remained on the column. Samples were concentrated by evaporating the CHzClz with Nz if necessary to detect nonvolatile compounds which were present at low con-
centrations in the extract. Gas chromatography mass spectroscopy (GC-MS) analyses [HP Model 5890 GC apparatus coupled to an H P COM-MS (9133-5890-5970series)] provided the initial identifications of compounds in the BSA denuder extracts. Some aqueous sample extracts were extracted twice with CHZClzto determine the extraction efficiency for the transfer from the basic aqueous solution to CH2C12. Extraction efficiencies were also determined in standard addition experiments. The extraction efficiencies were all close to 80% for one extraction. All reported concentrations have been corrected for the extraction efficiency for each compound. The ion chromatography (Dionex Model 2000I/SP) determination of nicotine was accomplished with an MPIC column and a UV (254-nm) detector. The eluent was 10 vol % CH3CN/90 vol % H 2 0 and 5 mM hexanesulfonic acid. Anions were determined by using a AG5 anion column with either 3.0 mM NaHC03/2.5 mM Na2C03or 5.0 mM NaHC03 as eluent with a cation fiber suppressor (HZSO4)and conductivity detection. Standard aqueous solutions for the IC analyses were prepared by weight from reagent-grade material. Effect of UV Light on the Concentrations of Organic Bases. Three experiments in the 30-m3environmental chamber were performed to test the effect of UV radiation on the concentration of nicotine and other organic bases in environmental tobacco smoke. The UV radiation was provided by 200 F40BL General Electric black lights (365 nm) and 12 FS40UVB sunlamps (Commercial Lighting, Salt Lake City, UT). The purpose of these experiments was to determine the reactivity of various environmental tobacco smoke constituents under extreme environmental stress. The results would be used as one of the criteria for deciding which compounds would serve as conservative tracers in an indoor environment. In the first two experiments, two BSA annular denuder sets sampled the environmental tobacco smoke for the f i s t hour of the experiment following combustion of four cigarettes. After the collection of the first sample set, the UV lights were turned on for the second hour. Two additional BSA denuder sets were then sampled for the third hour with the lights off. The lights were again turned on for the fourth hour of the experiment and then turned off while two BSA denuder acts sampled during the fifth hour. In the second experiment, the same procedure was followed except that there were only two sampling periods instead of three. In the third experiment, two BSA denuder sets sampled for 1 h, and then the UV lights were turned on and remained on for another l-h sampling period with two BSA denuder sets and also for a third l-h sampling period, which started 2.5 h after the end of the second sampling period. The lights were on continually after the collection of the first set of samples. Denuder sections from this and the previous two experiments were extracted and analyzed by GC-FID for organic bases as described above. Determination of Gas-Phase Inorganic Acids and Bases. Gas-phase HNOZ,HNO,, and SO2 concentrations were measured with two or three NaHC03-coated annular denuders. In one experiment, the concentrations of gasphase HN02 and HNO, were also determined with a cylindrical Nylon denuder (45). Each denuder set was followed by a filter pack consisting of a 47-mm Teflon fiiter and two 47-mm Nylon (Gelman Sciences, Inc.) backup filters for the collection of particulate-phase nitrite, nitrate, and sulfate. Ammonia and particulate ammonium ion concentrations were measured with two oxalic acid coated annular denuders followed by a Teflon or quartz filter and Environ. Sci. Technoi., Vol. 23, No. 6, 1989
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two oxalic acid coated fast-flow backup filters. The methods used for sample recovery and analyses for inorganic acids and bases have been described (40). Nine experiments to characterize the gas- and particle-phase acids and bases in environmental tobacco smoke by annular denuder/filter pack sampling were performed. Four cigarettes were combusted in each of the experiments, which were all carried out in the 30-m3 chamber. One NaHC03 annular denuder set sampled for an entire 3-h experimental period, while NaHC03 or oxalic acid annular denuder sets in the subsequent five experiments sampled only during the first and third hours of the experimental period. In the final three experiments, two NaHC03 annular denuder sets each were collected during two consecutive 2-h periods. Flow rates for the denuder sampling systems ranged from 7 to 12 slpm. After sampling, denuders were extracted with 5 mL of H20, Teflon filters with 4 mL of H20,and Nylon filters or denuder strips with eluent for IC analysis. The eluent used in the anion analyses was 3.0 mM NaHC03/2.4 mM Na2C03. Extracted ammonium ion was analyzed spectrophotometrically. Results and Discussion The Diffusion Coefficient of Gas-Phase Nicotine. The use of a diffusion denuder for the collection and determination of a gas-phase compound in environmental sampling (40,45) is best accomplished if the denuder surface is a perfect sink for the gas-phase compound to be determined. The deposition of gas-phase nicotine in a cylindrical diffusion denuder with quantitative adsorption of the nicotine following every collision with the denuder wall is described by the Gormley-Kennedy equation (45): G, = 0.819T,[e3.657Didt,/r2- 1]e-3.657Dit,/$ j > 1 (1) where Gi is the amount deposited in the j t h section of the denuder, T, is the total amount entering the denuder, Di is the gas diffusion coefficient at the experimental conditions, dt, is the axial displacement time for transport through equal-length sections of the denuder, t j is the axial displacement time for travel of the gas from the inlet through section j , and r is the radius of the cylindrical diffusion denuder. A corresponding equation has also been developed for collection of a gas by an annular diffusion denuder (42): C/Co 0.819e-22.5("DC/4F)(dl+dd/(dz - 4 ) (2) where Co is the amount of gas entering the denuder, C is the amount of gas leaving the denuder, Di is the gas diffusion coefficient at the experimental conditions, L is the length of the denuder (cm), F is the flow rate of the gas through the denuder (slpm), and dl and d2 are the inside and outside diameters (cm) of the annulus, respectively. An experimental value for the diffusion coefficient of gas-phase nicotine in air has not been reported in the literature. The diffusion coefficient has been estimated from gas diffusion laws to be 0.063 f 0.005 cma/s (36). Ideally, the gas-phase compound collected by a diffusion denuder will have a deposition pattern described by eq 1 or 2 for collection with a cylindrical or annular diffusion denuder, respectively. T o experimentally determine the diffusion coefficient for a gas, it must also be possible to quantitatively remove the compound from the denuder surface for analysis. The benzenesulfonic acid diffusion denuder system proved to be suitable for the collection of gas-phase nicotine. The total collection efficiency of six BSA cylindrical denuder sections was determined to be 91% at 2 slpm, and 682
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the efficiency of one BSA annular denuder section was 89% a t 18 slpm flow rate and 100% at 5 slpm flow rate. Experiments in which nicotine was collected by sequential BSA-saturated filters showed that the collection efficiency of each filter is 93%. The diffusion denuder data obtained by sampling the pure gas-phase nicotine or nicotine in environmental tobacco smoke allowed the determination of the diffusion coefficient, Do, for nicotine (36). Do values, corrected to 1atm and 25 "C,were calculated by weighted least-squares fit of the data to eq 1 or 2, depending on the denuder system used. The data were weighted by using the uncertainty in the determined concentration of nicotine in each denuder section. The results of these weighted linear regression analyses for the diffusion denuder data are well-described by eq 1 or 2 (36). The average experimentally determined Do value obtained by using the cylindrical diffusion denuder was 0.065 f 0.006 cmz/s for pure nicotine and 0.060 f 0.008 cmz/s for nicotine in environmental tobacco smoke. This indicates that only gas-phase nicotine is being collected by the cylindrical diffusion denuder even when particles are present. Only two or three data points were obtained with the BSA-coated annular diffusion denuder for each sample of pure gas-phase nicotine collected. An approximate Do value of 0.072 f 0.021 cm2/s determined from these data is in agreement with the Do value obtained from the data for the BSA-coated cylindrical diffusion denuder system. Gas-Phase Nicotine and Other Organic Bases in Environmental Tobacco Smoke. In the initial experiments performed in the 10-m3environmental chamber, the major emphasis of the sampling effort was the quantitative collection of gas- and particulate-phase nicotine. After a suitable denuder surface for the collection of nicotine had been identified, the emphasis of the sampling program was broadened to include the identification of unknown potential conservative tracers of environmental tobacco smoke. In addition to nicotine, 16 gas-phase organic bases were detected and 14 were identified in BSA denuder extracts by GC-MS. Quantitative results were obtained by GC-FID for the compounds given in Table I. Compounds identified by GC-MS for which quantitative results were not obtained included all possible pyridine m o m and dimethyl-substituted isomers, an ethyl-substituted isomer, 2-methyl-lH-pyrrol0[2,3-b]pyridine, and bipyridine. The GC-MS identification of particulate-phase environmental tobacco smoke compounds is presented in a separate paper (41) . The data obtained with the annular denuder/fiiter pack system allow the calculation of the concentration of gasphase nicotine, 3-ethenylpyridine, 2-ethenylpyridine, pyridine, myosmine, cotinine, and nicotyrine. Standard calibration curves were generated for the GC-FID analysis of nicotine, 4- and 2-ethenylpyridine, pyridine, cotinine, and nicotyrine. The myosmine and 3-ethenylpyridine peaks were identified in the GC-FID chromatogram on the basis of a comparison of relative peak heights and retention times with the data obtained from the GC-MS analysis. Myosmine and 3-ethenylpyridine are not available commercially and thus were quantitated by using the nicotine and the 2- and 4-ethenylpyridine calibration curves, respectively. The gas-phase concentrations were obtained from the diffusion denuder extract data. The results are given in Table I. All concentrations were obtained from samples collected in 30-m3 chamber experiments except as indicated. Particulate-phase species concentrations in environmental tobacco0 smoke are given in a subsequent report (41).The sum of gas- and particulate-phase com-
Table I. Concentrations of Gas-Phase Organic Nitrogen Compounds in Environmental Tobacco Smoke in a 30-maTeflon Experimental Chambef species measd nicotine, nmol/m3
1
no. of cigarettes burned in environmental chamber 2 3 2607 f 908
1823 f 318 1850 f 28gb 12750 f 5400 8760 f 890b 59 f 7
10100 f 1900
myosmine, pmol/mol of CO
410 f 140
313 f 110
nicotyrine, . nmol/ms
ND
ND
nicotyrine, pmol/mol of CO
ND
ND
