Improved gas chromatographic determination of nicotine in environmental tobacco smoke

Partial Vapor Pressures, Activity Coefficients, Henry Volatility, and Infinite Dilution Activity Coefficients of Nicotine from Binary Mixtures with Glycerol and with 1,2-Propanediol at 298.15 K

The equilibrium headspace concentration of nicotine in nitrogen gas was measured by gas chromatography for binary mixtures of nicotine with glycerol and with 1,2-propanediol at temperatures near 298.15 K. The storage temperature ranged from 296.25 to 298.25 K. The nicotine mole fraction ranged from 0.0015 ± 0.00010 to 0.998 ± 0.0016 for the glycerol mixtures and 0.00506 ± 0.000019 to 0.999 ± 0.0038 for the 1,2-propanediol mixtures (k = 2 expanded uncertainty). The headspace concentration was converted to nicotine partial pressure at 298.15 K using the ideal gas law, followed by the Clausius-Clapeyron equation. Both solvent systems had a positive deviation of nicotine partial pressure from ideal behavior, but the deviation of the glycerol mixtures was much greater than that of the 1,2-propanediol mixtures. For mole fractions of about 0.02 or less, the glycerol mixtures had nicotine activity coefficients of 11, while that for the 1,2-propanediol mixtures was 1.5. The Henry's law volatility constant and infinite dilution activity coefficient ± expanded uncertainty for nicotine from glycerol mixtures (51.4 ± 1.8 Pa and 12.4 ± 1.5, respectively) were approximately an order of magnitude greater than those from 1,2-propanediol mixtures (5.26 ± 0.52 Pa and 1.42 ± 0.14, respectively).

Airborne exposure and biological monitoring of bar and restaurant workers before and after the introduction of a smoking ban

The aims were to assess the impact of a total smoking ban on the level of airborne contaminants and the urinary cotinine levels in the employees in bars and restaurants. In a follow up design, 13 bars and restaurants were visited before and after the implementation of a smoking ban. Ninety-three employees in the establishments were initially included into the study. The arithmetic mean concentration of nicotine and total dust declined from 28.3 microg m(-3) (range, 0.4-88.0) and 262 microg m(-3) (range, 52-662), respectively, to 0.6 microg m(-3) (range, not detected-3.7) and 77 microg m(-3) (range, not detected-261) after the smoking ban. The Pearson correlation coefficient between airborne nicotine and total dust was 0.86 (p < 0.001; n = 48). The post-shift geometric mean urinary cotinine concentration declined from 9.5 microg g(-1) creatinine (cr) (95% CI 6.5-13.7) to 1.4 microg g(-1) cr (95% CI 0.8-2.5) after the ban (p < 0.001) in 25 non-snuffing non-smokers. A reduction from 1444 microg g(-1) cr (95% CI 957-2180) to 688 microg g(-1) cr (95% CI 324-1458) was found (p < 0.05) in 29 non-snuffing smokers. The urinary cotinine levels increased from 11.7 microg g(-1) cr (95% CI 7.0-19.6) post-shift to 21.9 microg g(-1) cr (95% CI 13.3-36.3) (p < 0.01) in the next morning in 24 non-snuffing non-smokers before the smoking ban. A substantial reduction of airborne nicotine and total dust was observed after the introduction of a smoking ban in bars and restaurants. The urinary cotinine levels were reduced in non-smokers. The decline found in smokers may suggest a reduction in the amount of smoking after intervention. In non-smokers cotinine concentrations were higher based on urine sampled the morning after a shift than based on urine sampled immediately post-shift.

Seasonal assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Bremen using personal monitoring

The study was designed to determine seasonal differences in personal exposures to respirable suspended particles (RSP) and environmental tobacco smoke (ETS) for nonsmokers in Bremen, Germany. The subjects were office workers, either living and working in smoking locations or living and working in nonsmoking locations. One hundred and twenty four randomly selected nonsmoking subjects collected air samples close to their breathing zone by wearing personal monitors for 24 h or, in some cases, for 7-day periods during the winter of 1999. The investigation was repeated in the summer with 126 subjects, comprised of as many of the studied winter population (89 subjects) as possible. Saliva cotinine analyses were undertaken to verify the nonsmoking status of the subjects. Subjects wore one personal monitor while at work and one while away from the workplace on weekdays, and a third monitor at the weekend. Collected air samples were analysed for RSP, nicotine, 3-ethenylpyridine (3-EP) and ETS particles. The latter were estimated using ultraviolet absorbance (UVPM), fluorescence (FPM) and solanesol (SolPM) measurements. ETS exposure was consistently higher in the winter than in the summer, this pattern being particularly evident for subjects both living and working with smokers. The highest median 24-h time weighted average (TWA) concentrations of ETS particles (SolPM, 25 microg m(-3)) and nicotine (1.3 microg m(-3)) were recorded for subjects performing weekday monitoring during the winter. These were significantly higher than equivalent levels of ETS particles (SolPM, 2.4 microg m(-3)) and nicotine (0.26 microg m(-3)) determined during the summer. There were no appreciable differences between winter and summer percent workplace contributions to median TWA ETS particle and nicotine weekday concentrations, the workplace in Bremen, in general, contributing between 35% and 61% of reported median concentrations. Workers, on average, spent one-third of their time at work during a weekday, indicating that concentrations were either comparable or higher in the workplace than in the home and other locations outside the workplace. Median 24-h weekend ETS particle and nicotine concentrations for smoking locations were not significantly different from equivalent weekday levels during the winter, but were significantly lower during the summer. Based upon median 24-h TWA SolPM and nicotine concentrations for the winter, extrapolated to 1 year's ETS exposure, those subjects both living and working in smoking locations (the most highly exposed group) would potentially inhale 13 cigarette equivalents/year (CEs/y). However, based on a similar extrapolation of summer measurements, the same group of subjects would potentially inhale between 1.3 and 1.9 CEs/y. The most highly exposed subjects in this study, based upon 90th percentile concentrations for those both living and working in smoking locations during the winter, would potentially inhale up to 67 CEs/y in the winter and up to 22 CEs/y in the summer. This clearly demonstrates that seasonal effects should be taken into account in the design and interpretation of ETS exposure studies. Air sampling over a 7-day period was shown to be technically feasible, and subsequent RSP, ETS particle and nicotine levels determined by 7-day monitoring were not found to be significantly different from equivalent levels determined by 24-h monitoring. However, the longer sampling period resulted in the collection of an increased quantity of analytes, which improved the limits of quantitation (LOQ) and allowed a more accurate determination of low level ETS exposure. This was reflected by a reduced percentage of data falling below the LOQ for 7-day monitoring compared with 24-h monitoring. The use of a liquid chromatographic method with tandem mass spectrometric detection for saliva cotinine measurement afforded a greatly improved LOQ and greater accuracy at low concentrations compared with the radioimmunoassay (RIA) method used in previous studies by these authors. In this study, 17 subjects out of 180 tested (9.4%) were found to have saliva cotinine levels exceeding the selected threshold of 25 ng ml(-1) used to discriminate between smokers and nonsmokers.

Measurement of nicotine in hair by reversed-phase high-performance liquid chromatography with electrochemical detection

We have developed an assay for nicotine in hair based on reversed-phase HPLC with electrochemical detection. The method uses a low-metal, high-purity silica reversed-phase column. We have investigated the washing, digestion and extraction procedures and discuss the important points in the HPLC method development. The assay is presented as an application in a population of exposed and non-exposed children. Analytical parameters are satisfactory with linearity, recoveries, limit of quantitation and precision all suitable for epidemiological studies involving environmental tobacco smoke exposure assessment.

Dynamic behavior of semivolatile organic compounds in indoor air. 2. Nicotine and phenanthrene with carpet and wallboard

The surface interactions of nicotine and phenanthrene with carpet, painted wallboard, and stainless steel were investigated in a room-sized environmental test chamber. Adsorption kinetics were tested by flash evaporating a known mass of each compound into a sealed 20 m3 chamber containing one or more of the tested sorbents. In each experiment, one or more emissions were performed after the gas-phase concentration had reached an apparent plateau. At the end of each experiment, the chamber was ventilated and resealed to monitor reemission of the compound from the sorbents. Kinetic sorption parameters were determined by fitting a mass-balance model to the experimental results. The sorption capacity of stainless steel was of similar magnitude for nicotine and phenanthrene. Sorption of nicotine on carpet and wallboard was much stronger, with equilibrium partitioning values 2-3 orders of magnitude higher. The sorption capacities of phenanthrene on carpet and wallboard were smaller, approximately 10-20% of the stainless steel values. The rates of uptake are of similar magnitude for all sorbate--sorbent pairs and are consistent with the limit imposed by gas-phase boundary-layer mass transport. The rates of desorption are much faster for phenanthrene than for nicotine. Model simulations predict average nicotine levels in a typical smoking residence that are consistent with published data.

Nicotine as a Marker for Environmental Tobacco Smoke: Implications of Sorption on Indoor Surface Materials

Recently developed models and data describing the interactions of gas-phase semi-volatile organic compounds with indoor surfaces are employed to examine the effects of sorption on nicotine's suitability as an environmental tobacco smoke (ETS) marker. Using parameters from our studies of nicotine sorption on carpet, painted wallboard, and stainless steel and previously published data on ETS particle deposition, the dynamic behavior of nicotine was modeled in two different indoor environments: a house and a stainless steel chamber. The results show that apparently contradictory observations of nicotine's behavior in indoor air can be understood by considering the effects of sorption under different experimental conditions. In indoor environments in which smoking has occurred regularly for an extended period, the sorbed mass of nicotine is very large relative to the mass emitted by a single cigarette. The importance of nicotine adsorption relative to ventilation as a gas-phase removal mechanism is reduced. Where smoking occurs less regularly or the indoor surfaces are cleaned prior to smoking (as in a laboratory chamber), nicotine deposition is more significant. Nicotine concentrations closely track the levels of other ETS constituents in environments with habitual smoking if the data are averaged over a period significantly longer than the period between cigarette combustion episodes. However, nicotine is not a suitable tracer for predicting ETS exposures at fine time scales or in settings where smoking occurs infrequently and irregularly.

Assessment of air quality in Stockholm by personal monitoring of nonsmokers for respirable suspended particles and environmental tobacco smoke

Exposure to respirable suspended particles (RSP) from all sources and environmental tobacco smoke (ETS) was assessed for 190 nonsmokers in Stockholm during 1994. Each subject wore a personal monitor for 24-h, provided saliva samples for cotinine analysis, and completed a detailed questionnaire about air quality and life-style. The subjects consisted of housewives and househusbands in one main group and working men and women in the second. The housewives and househusbands wore a single monitor throughout the 24-h period and the working subjects wore one monitor at work and a separate monitor while not at work. The geodemographic distribution of the recruited subjects accurately reflected the population of Stockholm. For most of the subjects, exposure to ETS and nicotine was at or below the limits of quantification (LOQ). This finding was supported by the fact that about 80% of the recruited subjects claimed that their exposure to ETS was "none" or "low". The concentration of RSP was found to be highest (median 39 micrograms.m-3) in homes where smoking occurred and below the LOQ in the workplace irrespective of its smoking status. These levels are at the lowest end of typical indoor air levels for RSP. For the housewives and househusbands living in smoking homes (nonsmoking homes in parentheses), the median exposure levels were 39 micrograms.m-3 (18 micrograms.m-3) for RSP, 17 micrograms . m-3 (0.12 micrograms . m-3) for ETS particles, and 1.1 micrograms.m-3 (0.05 micrograms.m-3) for nicotine. Both the pre- and postmonitoring continine saliva levels measured for these housewives and househusbands were 2.9 ng.ml-1 (pre-0.56 ng.ml-1, post-0.41 ng.ml-1). The highest exposure levels were recorded for the housewives and househusbands in the age range of 35-49 years. For the working subjects, the exposure measured in smoking workplaces (nonsmoking workplaces in parentheses) gave median levels of 16 micrograms.m-3 (16 micrograms.m-3) for RSP, 1.1 micrograms.m-3) for ETS particles and 0.2 micrograms.m-3 (0.15 microgram.m-3) for nicotine. Similarly measured exposures at home (nonsmoking homes in parentheses), including all other locations outside the workplace, gave median levels of 24 micrograms.m-3 (19 micrograms.m-3) for RSP, 1.4 micrograms. m-3 (0.2 microgram.m-3) for ETS particles, and 0.15 microgram.m-3 (0.07 microgram.m-3) for nicotine. Overall, the exposure levels of ETS due to living with smokers in Stockholm was found to be much lower than similar exposures measured previously in the United Kingdom and the United States. Over 70% of all the nicotine measurements and 60% of all the ETS measurements were below the LOQ. When the median values for nicotine and ETS particles are converted to cigarette equivalents, Stockholm housewives and househusbands living with smokers would receive 6-9 cigarette equivalents per year, working nonsmokers living with smokers would receive 0.6-0.7 cigarette equivalents at home, and nonsmokers working with smokers would be exposed to 0.1-0.2 cigarette equivalent at work. The exposures were therefore up to six times greater at home than in workplaces where smoking was occurring. Although all the subjects were recruited as nonsmokers on the basis of their self-reported nonsmoking status, saliva continine measurements were used for confirmation. Subjects with continine levels below 25 ng.ml-1 were considered to be nonsmokers although the selection of a threshold level within the range of 10-50 ng.ml-1 was not considered to be critical. With a threshold of 25 ng.ml-1, between 2.7% and 5.3% were later shown to be misclassified as nonsmokers, depending on the definition of misclassification used. During the study period the air quality in Stockholm could be described according a British nomenclature as "very good" for the majority of the time. The daily average at no time fell below "good," and the maximum hourly nitrogen dioxide level was 111 micrograms.m-3 (inner city at street level) on the coldest day