Smoke Samples Research Articles

Quantifying Non‐Covalent Binding Interactions between Tobacco Alkaloids and Cyclodextrin Using Mass Spectrometry and the Application in Cigarette Smoke

Quantifying Non‐Covalent Binding Interactions between Tobacco Alkaloids and Cyclodextrin Using Mass Spectrometry and the Application in Cigarette Smoke

Effects of combustion condition and biomass type on the light absorption of fine organic aerosols from fresh biomass burning emissions over Korea

In this study, the light absorption properties of fine organic aerosols from the burning emissions of four biomass materials were examined using UV-spectrophotometry and Aethalometer-measurements, respectively. For wood chips and palm trees, the burning experiments were carried out with different combustion temperatures (200, 250, and 300 οC) in an adjustable, electrically heated combustor. The light absorptions of water and methanol extracts of aerosols, and smoke particles showed strong spectral dependence on the burning emissions of all biomass materials. However, the burning aerosols of wood chips showed stronger absorption than those of the other biomass burning (BB) emissions. For the burning aerosols of wood chips and palm trees, organic carbon/elemental carbon (OC/EC) decreased as the combustion temperature increased from 200 to 300 °C. Absorption Ångström exponent (AAE) values tended to decrease when combustion temperature increased for smoke aerosols and methanol extracts in smoke samples. The mass absorption efficiency at 365 nm (MAE365, m2 g−1∙C−1) of water- and methanol-extractable OC fractions was highest in wood chip burning smoke samples. MAE365 values of methanol extracts for rice straw, pine needles, wood chips, and palm trees burning emission samples were 1.35, 0.92, 2.36–3.37, and 0.86–1.42, respectively. For wood chip and palm tree burning emissions, AAE320–430nm values of methanol extracts were strongly correlated with OC/EC (i.e., combustion temperature) with slopes of 0.11 (p < 0.001) and 0.02 (p < 0.001), and R2 values of 0.87 and 0.74, respectively. Moreover, a linear regression between MAE365 of methanol extractable OC and OC/EC showed slopes of −0.05 (p < 0.001) and −0.004 (p < 0.001) and R2 of 0.72 and 0.74, respectively. The results of this study clearly demonstrate that burning condition and biomass type influence the light absorption properties of organic aerosols from BB emissions.

Development of a standardized new cigarette smoke generating (SNCSG) system for the assessment of chemicals in the smoke of new cigarette types (heat-not-burn (HNB) tobacco and electronic cigarettes (E-Cigs))

To systematically regulate new types of cigarettes for which their safety has yet to be verified, such as heat-not-burn (HNB) products and electronic cigarettes (E-Cigs), the identification of chemicals in the new cigarette smoke is necessary. However, this is challenging due to the large number of new cigarette types and their different vaporization approaches. To address this issue, we herein report the development of a standardized new cigarette smoke generating (SNCSG) system based on heating-temperature control, which is able to generate smoke for all types of new cigarettes. Validation of the developed system was also carried out through analysis of the carbonyl compounds (e.g., formaldehyde and acetaldehyde) in the new cigarette smoke of HNB products and E-Cigs generated by the SNCSG system under different heating temperatures. The analytical results were used to validate the SNCSG system by comparison with those of previous studies. In all new cigarette smoke samples, the formaldehyde and acetaldehyde concentrations increased dramatically upon increasing the heating temperatures, especially over the reference heating range of each HNB device (mean concentration (μg/cigarette, n = 5 (HNB and E-Cig samples)): formaldehyde = 0.373–5.841 (250–320 °C), and acetaldehyde = 0.088–27.60 (250–320 °C). In the case of the HNB samples, the concentration differences determined by the heating temperatures of the tobacco stick were statistically significant, with p-values (ANOVA) of 1.85E−10 (formaldehyde) and 1.73E−08 (acetaldehyde). In the majority of smoke samples, acrolein and propionaldehyde were detected under relatively high heating temperature conditions (>250 °C) at 0.50 ± 1.76 μg/(cigarette or 10 μL), while acetone was detected under low heating temperature conditions (<250 °C) at 0.09 ± 0.17 μg/(cigarette or 10 μL). These results indicate that the developed SNCSG system could be suitable for application in the regulation of new types of cigarettes, regardless of the cigarette type and heating approach.

Immune modulation by chronic exposure to waterpipe smoke and immediate-early gene regulation in murine lungs

ObjectiveWe investigated the effects of chronic waterpipe (WP) smoke on pulmonary function and immune response in a murine model using a research-grade WP and the effects of acute exposure on...

Untargeted Metabolomics Analysis of Wood Smoke and Diesel Exhaust Particulate Matter

TPS 711: The exposome, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: Untargeted metabolomics analysis is a valuable tool in the field of metabolic profiling of biological samples, but it has been less widely applied to characterization of environmental mixtures. The current study explores using untargeted analysis of environmental samples of air pollution for component analysis and source appointment. Methods: Particulate matter (PM) in wood smoke and diesel exhaust were collected in laboratory settings at the University of Washington. Total suspended particles were collected using 37 mm Teflon filtration membranes (PALL Corporation, USA) in open-face cassettes attached to air sampling pumps (AirChek XR5000, SKC Inc., USA). After sample extraction (Methanol), concentration and reconstitution (25μL Methanol and 25μL 0.4% (v/v) acetic acid), PM samples were analyzed by accurate-mass Q-TOF (Agilent 6500) for separation and qualification. We used MetaboAnalyst (version 4.0) to perform principal component analysis (PCA) to visualize the data and t-tests to compare chemical features between wood smoke and diesel exhaust groups. Results: We collected and analyzed six wood smoke PM samples (weight = 65 ± 3 μg) and five diesel exhaust PM samples (average weight = 150 ± 1 μg). Using Q-TOF HPLC/MS, we detected 1513 chemical features from the PM samples. In a volcano plot, a total of 112 chemical features were identified that exhibited differences (fold-change > 2, and p-value < 0.05) between PM from the wood smoke and diesel exhaust. PCA showed that 81.3% of the variance was explained when including the 5 most significant principal components (PC). Both the 2-D scores plot and 3-D score plot between selected PCs totally separated wood smoke and diesel exhaust PM samples. Conclusion: Untargeted metabolomics analysis detected numerous chemical features from wood smoke and diesel exhaust PM samples. The untargeted analysis has the potential to be used in air pollution studies for components analysis and source appointment of PM.

Highly Speciated Measurements of Terpenoids Emitted from Laboratory and Mixed-Conifer Forest Prescribed Fires.

Wildland fires in the western United States are projected to increase in frequency, duration, and size. Characterized by widespread and diverse conifer forests, burning within this region may lead to significant terpenoid emissions. Terpenoids constitute a major class of highly reactive secondary organic aerosol (SOA) precursors, with significant structure-dependent variability in reactivity and SOA-formation potential. In this study, highly speciated measurements of terpenoids emitted from laboratory and prescribed fires were achieved using two-dimensional gas chromatography. Nearly 100 terpenoids were measured in smoke samples from 71 fires, with high variability in the dominant compounds. Terpenoid emissions were dependent on plant species and tissues. Canopy/needle-derived emissions dominated in the laboratory fires, whereas woody-tissue-derived emissions dominated in the prescribed fires. Such differences likely have implications for terpenoid emissions from high vs low intensity fires and suggest that canopy-dominant laboratory fires may not accurately represent terpenoid emissions from prescribed fires or wildland fires that burn with low intensity. Predicted SOA formation was sensitive to the diversity of emitted terpenoids when compared to assuming a single terpene surrogate. Given the demonstrated linkages between fuel type, fire terpenoid emissions, and the subsequent implications for plume chemistry, speciated measurements of terpenoids in smoke derived from diverse ecosystems and fire regimes may improve air quality predictions downwind of wildland fires.

A sensitive method for the determination of tobacco-specific nitrosamines in mainstream and sidestream smokes of combustion cigarettes and heated tobacco products by online in-tube solid-phase microextraction coupled with liquid chromatography-tandem mass spectrometry

A simple and sensitive method, using automated online in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS), was developed for the determination of four tobacco-specific nitrosamines (TSNAs) in mainstream and sidestream smoke of combustion cigarettes and heated tobacco products. These TSNAs were separated within 4 min on a Capcell Pak C18 MGⅢ column and detected in the positive ion mode by multiple reaction monitoring. The optimum in-tube SPME conditions were 30 draw/eject cycles of 40 μL of sample at a flow rate of 200 μL min−1 using a Supel-Q PLOT capillary column as an extraction device. The extracted TSNAs were easily desorbed from the column by passage of the mobile phase, with no carryover observed. This in-tube SPME LC–MS/MS method showed good linearity for four TSNAs in the 0.5–100 pg mL−1 ranges, with correlation coefficients above 0.9998 (n = 24), using stable isotope-labeled TSNAs as internal standards. The validation assays for limit of detection, limit of quantification, specificity, precision and accuracy of the analytes were consistent with the requirements recommended by the ICH guidelines. The validated method was utilized successfully to analyze four TSNAs in mainstream and sidestream smoke samples without any interference peaks. Overall recoveries of TSNAs spiked into smoke sample solutions were 97.3–104.6%. The developed method can automate the extraction, concentration and analysis of samples, and is sensitive and selective for TSNAs. This method was used to analyze TSNAs in mainstream and sidestream smoke samples of several commercially available combustion cigarettes and heated tobacco products.

Analysis of chemosensory markers in cigarette smoke from different tobacco varieties by GC×GC-TOFMS and chemometrics

Commercial cigarettes are made from a blend of different tobacco varieties, which in turn are the results of different agronomic practices and post-harvest curing processes. The highly complex mixture of smoke compounds reflects each tobacco variety and the levels of sensory-relevant markers. Therefore, the aim of this work was to identify potential relevant chemosensory markers in the mainstream smoke of four main types of commercial tobaccos and establish any possible relationship between them and the tobacco growing/curing practices. The tobacco samples were segregated into four segments: (1) three curing stages of flue-cured Virginia, (2) three curing stages of air-cured Burley, (3) three geo-regions of sun-cured Oriental and (4) three different process applied to tobacco. One hundred and twenty cigarettes (10 batches per flavour category) were produced and smoked under standard machine-smoking protocols. The mainstream smoke samples collected were extracted and analysed by GC × GC TOFMS. The processed data was analysed by partial least square discriminant analysis (PLS-DA) and the selectivity ratio was used to identify key chemosensory markers responsible for the four segments. All models had sensitivity and specificity equal to unity. Flue-cured Virginia (193 markers) and air-cured Burley (184 markers) showed a similar trend for O-heterocycles markers in the lighter leaf colours and N-heterocycles in the darker leaf colours post-processing, but they had compounds of different flavour descriptions, e. g. sweet and nutty. The three geo-regions of sun-cured Oriental (290 markers) also presented O-heterocycles markers in correlation with leaf sugar contents in addition of sucrose esters markers. The three unusually processed tobacco generated many chemical markers (436 markers), some derived from the so-called Cavendish fermentation process with sweet, spicy and peppery notes, whereas the dark fermented air-cured tobacco presented similar descriptors as air-cured Burley. In addition, some polycyclic aromatic hydrocarbons (PAH) were detected as markers from the fire-curing process. The PLS-DA with selectivity ratio evidenced total of 1098 chemosensory markers in cigarette smoke, in which 173 were tentatively identified.

Design of Indoor Room Gas CO and SO2 Detection Based on Microcontroller Using Fuzzy Logic

The incidence of poisoning due to carbon monoxide gas arising from drilling activities on the first floor of a building in the Kelapa Gading beauty clinic in Jakarta resulted in 17 people experiencing poisoning. In this study developing a device on the sensor used to detect CO and SO2 gas, in the air of a closed room using gas sensor MQ 135 and MQ 136. The results of testing the CO and SO2 gas gauges using samples of cigarette smoke and sulfur powder using MQ 135 and MQ 136 sensors with fuzzy rule base logic for motor speed to produce CO and SO2 gas, that obtained a value of 0.233 ppm SO2 gas safe conditions and gas input CO with the sensor obtained a value of 0.513 ppm, the condition is safe so that the output is 49.8 ppm, the condition of the fan blower does not rotate. Whereas when the reading value of 5.0 ppm is very concentrated and the CO gas input with the sensor is 13.8 ppm the condition is very concentrated producing an output of 228 ppm the very danger.

Review—Recent Advances in Direct and Indirect Methods for Sensing Carbonyl Compounds Aldehydes in Environment and Foodstuffs

Aldehydes are chemicals substances widely distributed in nature and have been quantified in multiple matrices such as air, water, food and beverages. While these compounds with traces can contribute to the fresh aroma of different foods, when used in higher concentrations, they can facilitate the rancidity of foods and the release of taste. However, it is known that several aldehydes are irritating and carcinogenic. In addition, they are considered to be the potential marker for oxidative stress and metabolic status, which has been proposed to estimate cancer disease and symptoms of alcohol abuse. For these reasons, it is essential to establish a method for the determination of aldehydes in different samples. This paper review provides an insight into current knowledge on the methods and applications of aldehyde measurements, with an emphasis on analytical and electroanalytical techniques. Emphasis was put on the reactivity, specificity and toxicity of reactive aldehydes with respect to cellular targets and their concentrations measured in air, food and water. We discuss the different derivatization reagents used to measure aldehydes and their quantification in real matrices for human consumption such as drinking water, orange and apple vinegar, urine, serum, plasma, cigarette smoke, yogurt, and blood samples.

Adversarial Adaptation From Synthesis to Reality in Fast Detector for Smoke Detection

Video smoke detection is a promising method for early fire prevention. However, it is still a challenging task for application of video smoke detection in real-world detection systems, as the limitations of smoke image samples for training and lack of efficient detection algorithm. This paper proposes a method based on two state-of-the-art fast detectors, a single-shot multi-box detector, and a multi-scale deep convolutional neural network, for smoke detection using synthetic smoke image samples. The virtual data can automatically offer rich samples with ground truth annotations. However, the learning of smoke representation in the detectors will be restricted by the appearance gap between real and synthetic smoke samples, which will cause a significant performance drop. To train a strong detector with synthetic smoke samples, we incorporate the domain adaptation into the fast detectors. A series of branches with the same structure as the detection branches are integrated into the fast detectors for domain adaptation. We design an adversarial training strategy to optimize the model of the adapted detectors, to learn a domain-invariant representation for smoke detection. The domain discrimination, domain confusion, and detection are combined in the iterative training procedure. The performance of the proposed approach surpasses the original baseline in our experiments.

Measurements of I/SVOCs in biomass-burning smoke using solid-phase extraction disks and two-dimensional gas chromatography

Abstract. Biomass-burning organic-aerosol (OA) emissions are known to exhibit semi-volatile behavior that impacts OA loading during plume transport. Because such semi-volatile behavior depends in part on OA composition, improved speciation of intermediate and semi-volatile organic compounds (I/SVOCs) emitted during fires is needed to assess the competing effects of primary OA volatilization and secondary OA production. In this study, 18 laboratory fires were sampled in which a range of fuel types were burned. Emitted I/SVOCs were collected onto Teflon filters and solid-phase extraction (SPE) disks to qualitatively characterize particulate and gaseous I/SVOCs, respectively. Derivatized filter extracts were analyzed using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-TOFMS). Quality control tests were performed using biomass-burning relevant standards and demonstrate the utility of SPE disks for untargeted analysis of air samples. The observed chromatographic profiles of I/SVOCs in coniferous fuel-derived smoke samples were well correlated with each other, but poorly correlated with other fuel types (e.g., herbaceous and chaparral fuels). Emissions of benzenediol isomers were also shown to be fuel dependent. The combined Teflon and SPE filter data captured differences in gas-particle partitioning of the benzenediol isomers, with hydroquinone having a significantly higher particle-phase fraction than catechol due to its lower volatility. Additionally, the speciated volatility distribution of I/SVOCs in smoke from a rotten-log fire was estimated to evaluate the composition of potentially volatilized primary OA, which was entirely attributed to oxygenated (or other heteroatomic) compounds. The isomer-dependent partitioning and the speciated volatility distributions both suggest the need for better understanding of gas-phase and heterogenous reaction pathways of biomass-burning-derived I/SVOCs in order to represent the atmospheric chemistry of smoke in models.

Long-Term Stress and Concomitant Marijuana Smoke Exposure Affect Physiology, Behavior and Adult Hippocampal Neurogenesis

Marijuana is a widely used recreational drug with increasing legalization worldwide for medical purposes. Most experimental studies use either synthetic or plant-derived cannabinoids to investigate the effect of cannabinoids on anxiety and cognitive functions. The aim of this study was to mimic real life situations where young people smoke cannabis regularly to relax from everyday stress. Therefore, we exposed young adult male NMRI mice to daily stress and concomitant marijuana smoke for 2 months and investigated the consequences on physiology, behavior and adult hippocampal neurogenesis. Animals were restrained for 6-h/day for 5-days a week. During the stress, mice were exposed to cannabis smoke for 2 × 30 min/day. We burned 2 “joints” (2 × 0.8 g marijuana) per occasion in a whole body smoking chamber. Cannabinoid content of the smoke and urine samples was measured by HPLC and SFC-MS/MS. Body weight gain was recorded daily and we did unrestrained, whole body plethysmography to investigate pulmonary functions. The cognitive performance of the animals was evaluated by the novel object recognition and Y maze tests. Anxietyrelated spontaneous locomotor activity and self-grooming were assessed in the open field test (OFT). Adult neurogenesis was quantified post mortem in the hippocampal dentate gyrus. The proliferative activity of the precursor cells was detected by the use of the exogenous marker 5-bromo-20-deoxyuridine. Treatment effects on maturing neurons were studied by the examination of doublecortin-positive neurons. Both stress and cannabis exposure significantly reduced body weight gain. Cannabis smoke had no effect on pulmonary functions, but stress delayed the maturation of several lung functions. Neither stress, nor cannabis smoke affected the cognitive functioning of the animals. Results of the OFT revealed that cannabis had a mild anxiolytic effect and markedly increased self-grooming behavior. Stress blocked cell proliferation in the dentate gyrus, but cannabis had no effect on this parameter. Marijuana smoke however had a pronounced impact on doublecortin-positive neurons influencing their number, morphology and migration. In summary, we report here that long-term stress in combination with cannabis smoke exposure can alter several health-related measures, but the present experimental design could not reveal any interaction between these two treatment factors except for body weight gain.

Chemical characterization and safety assessment of dokha: An emerging alternative tobacco product

Dokha is known to be one of the most rapidly spreading alternative tobacco products (ATPs) in the Middle East and North Africa (MENA) region. It is smoked using a pipe known as Midwakh. There is no scientific research published on the chemical composition of dokha and only very little was done to investigate its impact on human health. Three different types of dokha were included in this study. The trace metals content in the dokha samples were analyzed using inductively-coupled plasma-optical emission spectroscopy and energy-dispersive X-ray spectroscopy-scanning electron microscope. Dokha smoke was generated using a device that simulates human smoking/puffing. The smoke samples were collected on Tenax and activated carbon adsorbent tubes followed by chemical analysis using thermal desorption-gas chromatography–mass spectrometry. The results showed the presence of toxic metals in dokha samples such as cobalt, cadmium, chromium, and lead in amounts classified as harmful to human health. In addition, the presence of several potentially harmful and even toxic organic compounds in dokha smoke was identified based on the available clinical data. These included 22 irritants, 3 known carcinogens, and 5 central nervous system (CNS) depressants in addition to several other compounds with miscellaneous effects. The findings of this work demonstrate evidence for the presence of potentially harmful and toxic metals and compounds in dokha tobacco as well as dokha smoke. More research is required to further investigate the clinical impact of dokha on human health.

In-situ analysis of the gas- and particle-phase in cigarette smoke by chemical ionization TOF-MS

Mainstream and sidestream smoke samples from two types of cigarette standards (3R4F and 1R5F) were directly analyzed by a chemical ionization mass spectrometer (CIMS). A Walton smoke machine was used to ensure the cigarette is smoked in an acceptably reproducible manner among experiments. Gas-phase material was analyzed in real time and particles were collected on a Nichrome filament, and desorbed at 500° C for analysis immediately after collection was complete. Nicotine was observed to be the most prevalent compound in both phases, indicative of its well-known partitioning behavior. Gas-phase species present in significant amounts in the sidestream samples include benzene, toluene, isoprene, pyridine, 3-ethenylpyridine, xylene, naphthalene, isoquinoline, myosmine, and nicotyrine. Mainstream gas samples exhibited different signatures, dominated by acetaldehyde, acetone, pyrrole, pyrroline, pyrrolidine, and phenolics. These may be indicative of the higher temperature combustion and filtration during each puff. Concentrations of each gas-phase compound were estimated from a mass calibration using toluene vapor. Spectra obtained for the particle-phase contain a complex mixture of high-molecular weight compounds, as previously observed by off-line methods, but also lower molecular weight semi-volatile compounds smaller than nicotine. This gas/particle partitioning may have implications concerning how some of these compounds are absorbed upon inhalation. These compounds are present in the particle-phase and the gas-phase. The soft ionization technique showed a promising result for rapidly identifying chemical differences among cigarette types, smoke streams, and phase.

PAHs in Size Fractionate Mainstream Cigarette Smoke, Predictive Deposition and Associated Inhalation Risk

ABSTRACTSize fractionated mainstream cigarette smoke (MCS) samples were collected with variable configuration cascade impactor (VCCI). Samples were extracted ultrasonically and analysis of sixteen priority polycyclic aromatic hydrocarbons (PAHs) was performed using high performance liquid chromatography (HPLC) coupled with UV-visible detector. Identification of PAHs were also carried out using gas chromatography coupled with mass spectrometry (GC-MS) technique. Data of size fractionate PAHs in MCS were used to calculate size dependent deposition in different compartment of human respiratory tract using multiple path particle dosimetry (MPPD) model. All brand cigarette smoke showed similar trends of particle mass and PAHs size distribution peaked at two sizes 0.3–0.1 µm and 0.75–1.13 µm aerodynamic diameter. All tested brands of MCS recorded around 48.75% of two and three-ring PAHs, 23 to 25% four-ring PAHs and 26–27% five and higher rings PAHs of total analyzed PAHs. Benzo[a]pyrene equivalent (B[a]Peq) PAHs emission in MCS was found to be 110 ± 12 (µ ± 1σ) ng per cigarette for tested brands. Total deposition fraction in respiratory tract was found to be 0.69 ± 0.26 for tested size ranges. Average 5th and 95th percentile values of incremental lifetime cancer risk (ILCR) for smoker due to PAHs exposure were found to be 1.3 × 10–5 to 3.9 × 10–5 respectively for tested cigarette brands.

Tobacco-Specific Nitrosamines in the Tobacco and Mainstream Smoke of U.S. Commercial Cigarettes.

Tobacco-specific nitrosamines (TSNAs) are N-nitroso-derivatives of pyridine-alkaloids (e.g., nicotine) present in tobacco and cigarette smoke. Two TSNAs, N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are included on the Food and Drug Administration's list of harmful and potentially harmful constituents (HPHCs) in tobacco products and tobacco. The amounts of four TSNAs (NNK, NNN, N-nitrosoanabasine (NAB), and N'-nitrosoanatabine (NAT)) in the tobacco and mainstream smoke from 50 U.S. commercial cigarette brands were measured from November 15, 2011 to January 4, 2012 using a validated HPLC/MS/MS method. Smoke samples were generated using the International Organization of Standardization (ISO) and Canadian Intense (CI) machine-smoking regimens. NNN and NAT were the most abundant TSNAs in tobacco filler and smoke across all cigarette brands, whereas NNK and NAB were present in lesser amounts. The average ratios for each TSNA in mainstream smoke to filler content is 29% by the CI smoking regimen and 13% for the ISO machine-smoking regimen. The reliability of individual TSNAs to predict total TSNA amounts in the filler and smoke was examined. NNN, NAT, and NAB have a moderate to high correlation (R2 = 0.61-0.98, p < 0.0001), and all three TSNAs individually predict total TSNAs with minimal difference between measured and predicted total TSNA amounts (error < 7.4%). NNK has weaker correlation (R2 = 0.56-0.82; p < 0.0001) and is a less reliable predictor of total TSNA quantities. Tobacco weight and levels of TSNAs in filler influence TSNA levels in smoke from the CI machine-smoking regimen. In contrast, filter ventilation is a major determinant of levels of TSNAs in smoke by the ISO machine-smoking regimen. Comparative analysis demonstrates substantial variability in TSNA amounts in tobacco filler and mainstream smoke yields under ISO and CI machine-smoking regimens among U.S. commercial cigarette brands.

Molecular and Carbon Isotopic Compositions of n-Alkanoic Acids in Smoke from Maize Straw Combustion

Four cultivars of maize straw were burned under flaming and smoldering conditions. Smoke samples were colleted and analyzed by GC/MS and GC/C/IRMS to determine molecular and stable carbon isotopic compositions of n-alkanoic acids in them. The results showed that n-alkanoic acids in flaming smoke were composed of C7 to C34, with a mean total content of 13895.0 mg·kg-1. The average ratio values of the content for homologues with lower carbon number (≤C16) to that for ones with higher carbon number (>C16) (L/H), C18/C16, C24/C16, C24/C18, and C24/(C22+C26) (CAR) were 1.1, 0.33, 0.17, 0.50, and 1.2, respectively. Moreover, the acids exhibited a bimodal profile with peaks at C16 and C24, respectively. They had evident even to odd carbon number predominance (mean CPI: 4.5). In smoldering smoke the acids were consisted of C6 to C34, with an average total content of 50183.7 mg·kg-1. The mean ratios of L/H, C18/C16, C24/C16, C24/C18, and CAR were 1.3, 0.33, 0.20, 0.60, and 1.6, respectively. In addition, the homologues had the same distribution pattern as in flaming smoke and even to odd carbon number predominance (mean CPI=6.1). The mean carbon isotopic ratio (δ13 C) values for individual n-alkanoic acids (C14 to C26) in flaming smoke ranged from -21.0‰ to -24.8‰, the overall average of which was -23.5‰. The difference between mean δ13 C values of n-fatty acids in flaming smoke and the straw (Δ13 C) was -0.7‰. In smoldering smoke, the mean δ13 C values for the compounds varied from -21.8‰ to -25.4‰, with an overall average of -23.3‰. The Δ13 C value was up to -0.5‰. The molecular and carbon isotopic compositions of n-alkanoic acids in smoke were significantly different from those in straw matter. L/H, C24/C16, C24/C18, CAR, and δ13 C might be useful proxies to discriminate the organic pollutants in atmospheric aerosols derived from maize straw combustion.

Correlation between Odor Concentration and Volatile Organic Compounds (VOC) Composition of Environmental Tobacco Smoke (ETS).

We examined the correlation between the odor concentration and the chemical composition of environmental tobacco smoke (ETS). Three types of ETS samples were prepared: secondhand smoke (SHS), thirdhand smoke (THS), and field ETS samples from an outside smoking area. The odor concentrations of the ETS, SHS, and THS samples were determined by the triangle-odor-bag method, and the chemical compositions were determined by proton transfer mass spectrometry. The odor concentration of the SHS samples was three or four orders of magnitude higher than that of the field ETS samples, and three orders of magnitude higher than that of the THS samples. The concentration ratios of the constituent chemicals in THS to those in SHS were about 10−4, corresponding to the ratio of the odor concentration. The concentration ratios of the constituent chemicals in the field ETS samples were much lower than the ratios of the odor concentrations. This suggests that the main contributing components to the odor of the field ETS samples are different from those in SHS and THS. The main contributors of the odor in the field ETS samples could be acetaldehyde, acetonitrile, acetic acid, and other unknown components with a mass-to-charge ratio (m/z) of 39 and 43.

Analysis of polycyclic aromatic hydrocarbons in cigarette samples using gel permeation chromatography clean-up by gas chromatography–tandem mass spectrometry

A new method using gel permeation chromatography (GPC) as clean-up by gas chromatography coupled to a triple quadrupole tandem mass spectrometry (GC–MS/MS) was established to measure the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in cigarette samples. GPC clean-up was employed to purify cigarette mainstream smoke samples collected from cigarettes in China, giving cleaner final extracts than traditional solid phase extraction (SPE). GC–MS/MS with a “pseudo” multiple reactive monitoring mode (PMRM) proved superior to the classic single quadrupole technique, with enhanced sensitivity and more accurate. Trace level PAHs could be readily confirmed by their retention times and characteristic ions. The concentrations of PAHs in these cigarette samples ranged from 455.9ng/cig to 1201.3ng/cig in the range of cigarette tar between 5mg and 12mg, with the main components being two-, three, and four-ring PAHs. When tar is over 10mg, there is 14.4% increase in PAH concentrations on average than that tar is between 8 and 10mg, while there is 28.6% decrease when tar is below 6mg. These results indicate that relative low-tar cigarettes provide relative low emission levels of PAHs.