Mainstream Cigarette Smoke Research Articles

Combined use of analyte protectants and precolumn backflushing for a robust, high-throughput quantitative determination of aroma compounds in cigarette mainstream smoke by gas chromatography-tandem mass spectrometry

Trace analysis of multi-targets in complex matrices such as cigarette smoke has always been a great challenge for analysts. In this paper, a high-throughput qualitative and quantitative method was developed and validated to determine 559 aroma compounds in mainstream smoke using gas chromatography-tandem mass spectrometry. Among four commonly used extraction solvents, dichloromethane showed obvious advantages in extracting the target aroma compounds with different polarity. An analyte protectant mixture consisting of 3-methoxy-1,2-propanediol, 1,2-octandiol, 1,2-nonanediol, and 1,2-tetradecanediol was first presented to compensate for the matrix effect, which was suitable for solvents of a wide polarity range such as hexane, dichloromethane, acetone, acetonitrile, and methanol. Moreover, the introduction of precolumn backflushing markedly improved the instrument robustness in analyzing complex cigarette smoke. The results showed that the system retained good stability after 30 days of injection. The proposed method performed well in terms of key validation parameters: accuracy (70.3–118.8% for 552 compounds), inter/intraday precision (0.1–10.7% and 0.2–18.2%), and sensitivity (limit of detection 0.12–102.54 ng/mL). Finally, this method was successfully applied to analyze 12 different commercial cigarette brands. The proposed method has good application prospects based on its robustness and may be used as a potential tool to transfer the cigarette design from an experience-dependent mode to a digital design mode. This method also shows potential in assaying aroma compounds in essentials, food or plant-based substrates.

Cigarette Smoke Extract Produces Superoxide in Aqueous Media by Reacting with Bicarbonate.

The toxicity of cigarette smoke (CS) is largely attributed to its ability to generate reactive oxygen species (ROS). Reportedly, CS generates superoxide in cell culture systems by stimulating the cells to produce superoxide and through direct chemical reactions with components of the culture media. In this study, we investigated CS-induced superoxide formation in biocompatible aqueous media and its characteristics. Cigarette smoke extract (CSE) and total particulate matter (TPM) were prepared from the mainstream smoke of 3R4F reference cigarettes. CSE and TPM generated superoxide in Hank’s balanced salt solution (HBSS), Dulbecco’s modified Eagle media (DMEM), and blood plasma, but not in distilled water and phosphate-buffered saline. Each constituent of HBSS in solution was tested, and bicarbonate was found to be responsible for the superoxide generation. More than half of the superoxide formation was abolished by pretreating CSE or TPM with peroxidase, indicating that the substrates of peroxidase, presumably peroxides and peroxy acids, mainly contributed to the superoxide production. In conclusion, the presence of bicarbonate in experimental conditions should be considered carefully in studies of the biological activity of CS. Furthermore, the local amount of bicarbonate in exposed tissues may be a determinant of tissue sensitivity to oxidative damage by CS.

Abstract 13900: Ex vivo Evaluation of Vascular Toxicity of Tobacco Products

Introduction: Tobacco smoke is the single most significant modifiable risk factor of cardiovascular disease (CVD), yet the contribution of electronic cigarettes (e-cig) to CVD risk is uncertain. Objective: The purpose of this study was to test an ex vivo approach for evaluation of vascular toxicity of tobacco products including e-cig aerosols. Methods: The assay relies on 2 facts of aortic function: 1) it is a biomarker of endothelial dysfunction; and, 2) it is nearly 100% dependent on endothelial-derived nitric oxide synthase (eNOS). To assess real-time eNOS function, phenylephrine-precontracted (PE) murine aortas were incubated with L-nitroargininemethylester (L-NAME) that subsequently increased tension and blocked (>99%) acetylcholine-induced relaxation (ACh %). The ‘L-NAME PE Contraction Ratio’ (PECR) was calculated as: ‘PE Tension post-L-NAME’ divided by ‘PE Tension pre-L-NAME’, and regressed vs ACh % relaxation. Results: Validation 1: PECR and ACh % values of naïve aortas were strongly and positively correlated (PECR vs ACh %, r 2 =0.91, n=7). Validation 2: Retrospective analyses of published PECR and ACh % data of aortic function of female mice exposed to air, propylene glycol:vegetable glycerin (PG:VG), formaldehyde (FA), or acetaldehyde (AA) for 4d, 6h/d showed that the PECR in air-exposed mice (PECR=1.42±0.04, n=16) correlated positively with the ACh % (r 2 =0.40) as in naïve aortas. Similarly, PECR values were significantly decreased in aortas with endothelial dysfunction yet retained positive regression coefficients (PG:VG r 2 =0.54; FA r 2 =0.55). Unlike other toxicants, AA exposure significantly increased both PECR and ACh % values yet diminished regression (r 2 =0.09). Validation 3: Naïve aortas were incubated (1h) with particles of either mainstream cigarette smoke (MCS) or PG:VG, and the PECR was significantly increased by MCS (1.97±0.17; p<0.05) yet not by PG:VG (1.34±0.05) compared with controls (1.48±0.05) indicating MCS induced vascular toxicity. Conclusions: Because the PECR reflects eNOS function directly, it is a robust tool for evaluating tobacco toxicity and predicting endothelial dysfunction. Thus, it strongly complements and extends insights gained using ex vivo measures of vascular toxicity.

The Effects of Cigarette Filter Ventilation on Delivery and Retention of Organic Acids

Summary A method for simultaneous identification and quantitative determination of 30 organic acids was established. The smoke yields and filter retentions of organic acids and routine smoke components, total particulate matter (TPM), nicotine-free dry particulate matter (NFDPM), nicotine and carbon monoxide (CO) at different filter ventilation levels were determined under both International Organization for Standardization (ISO) and Health Canadian Intense (HCI) smoking regimes. As a result of smoke dilution during filter ventilation, the yields of all organic acids were reduced in mainstream cigarette smoke. The spatial distribution pattern of the concentration of each organic acid in the filter was investigated at different ventilation levels and their filter retention determined. On one hand, the concentration of organic acids with a lower boiling point (BP) and lower molecular weight (MW) was relatively higher at the smoking end and the periphery part of the filter and spatial concentration distributions within the filter were significantly affected by smoke diffusion. On the other hand, those acids with high BPs and high MW were mainly distributed at the tobacco rod end and central part of the filter and spatial concentration distributions were only slightly influenced by their smoke diffusion within the filter whilst air compression around the filter vents also led to less change. This way, different acids in mainstream cigarette smoke were reduced to different extents which can also influence the acid-base equilibrium and sensory quality of the smoke. Compared with ISO smoking regime, the vent blocking and more intense smoking HCI regime led to different extents of yield increase for each of the studied acids. The effect of filter ventilation in the HCI smoking regime was not investigated, as the HCI smoking regime requires blocked ventilation holes. [Contrib. Tob. Nicotine Res. 30 (2021) 199–211]

A Low-Cost, High-Throughput Digital Image Analysis of Stain Patterns on Smoked Cigarette Filter Butts to Estimate Mainstream Smoke Exposure.

Standard machine smoking protocols provide useful information for examining the impact of design parameters, such as filter ventilation, on mainstream smoke delivery. Unfortunately, their results do not accurately reflect human smoke exposure. Clinical research and topography devices in human studies yield insights into how products are used, but a clinical setting or smoking a cigarette attached to such a device may alter smoking behavior. To better understand smokers’ use of filtered cigarette products in a more natural environment, we developed a low-cost, high-throughput approach to estimate mainstream cigarette smoke exposure on a per-cigarette basis. This approach uses an inexpensive flatbed scanner to scan smoked cigarette filter butts and custom software to analyze tar-staining patterns. Total luminosity, or optical staining density, of the scanned images provides quantitative information proportional to mainstream smoke-constituent deliveries on a cigarette-by-cigarette basis. Duplicate sample analysis using this new approach and our laboratory’s gold-standard liquid chromatography/tandem mass spectrometry (LC/MS/MS) solanesol method yielded comparable results (+7% bias) from the analysis of 20 commercial cigarettes brands (menthol and nonmentholated). The brands varied in design parameters such as length, filter ventilation, and diameter. Plots correlating the luminosity to mainstream smoked-nicotine deliveries on a per-cigarette basis for these cigarette brands were linear (average R2 > 0.91 for nicotine and R2 > 0.83 for the tobacco-specific nitrosamine NNK), on a per-brand basis, with linearity ranging from 0.15 to 3.00 mg nicotine/cigarette. Analysis of spent cigarette filters allows exposures to be characterized on a per-cigarette basis or a “daily dose” via summing across results from all filter butts collected over a 24 h period. This scanner method has a 100-fold lower initial capital cost for equipment than the LC/MS/MS solanesol method and provides high-throughput results (~200 samples per day). Thus, this new method is useful for characterizing exposure related to filtered tobacco-product use.

Targeted Characterization of the Chemical Composition of JUUL Systems Aerosol and Comparison with 3R4F Reference Cigarettes and IQOS Heat Sticks

Aerosol constituent yields have been reported from a wide range of electronic nicotine delivery systems. No comprehensive study has been published on the aerosol constituents generated from the JUUL system. Targeted analyses of 53 aerosol constituents from the four JUUL products currently on the US market (Virginia Tobacco and Menthol flavored e-liquids in both 5.0% and 3.0% nicotine concentration by weight) was performed using non-intense and intense puffing regimens. All measurements were conducted by an ISO 17025 accredited contract research organization. JUUL product aerosol constituents were compared to published values for the 3R4F research cigarette and IQOS Regular and Menthol heated tobacco products. Across the four JUUL products and two puffing regimes, only 10/53 analytes were quantifiable, including only two carbonyls (known propylene glycol or glycerol degradants). The remaining analytes were primary ingredients, nicotine degradants and water. Average analyte reductions (excluding primary ingredients and water) for all four JUUL system aerosols tested were greater than 98% lower than 3R4F mainstream smoke, and greater than 88% lower than IQOS aerosol. In summary, chemical characterization and evaluation of JUUL product aerosols demonstrates a significant reduction in toxicants when compared to mainstream cigarette smoke from 3R4F reference cigarettes or aerosols from IQOS-heated tobacco products.

Determination of Commonly Used Multiclass Pesticide Residues in Tobacco and Cigarette Smoke by Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry

A novel method has been developed for the simultaneous determination of multiclass pesticide residues in tobacco and cigarette smoke, using a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Cigarette mainstream smoke particulate was collected on a Cambridge filter pad. Pesticide residues was extracted with an aqueous solution, back extracted into acetonitrile after freezing, purified by dispersive solid phase extraction with primary-secondary amine adsorbents and analyzed by UPLC-MS/MS. The obtained mean recoveries of 16 pesticides commonly used on tobacco at three fortification levels (5.9, 94.1 and 352.9ngg-1) ranged from 69.3 to 115.9% with relative standard deviations between 2.4 and 11.3%. The limits of detection ranged from 0.14 to 13.28ngg-1. Finally, the proposed method was applied to study the pesticide smoke transfer ratio in 2 cigarettes with pesticide standard spiked and 51 cigarettes with one or more pesticide residues. The transfer ratio of pesticides residue in tobacco into the smoke might be much less than that from artificially spiked tobacco (<25%) with spiking levels varied from 1.88 to 9.41μgg-1. The transfer ratio of pesticide from artificially spiked tobacco into cigarette mainstream smoke was from 0.0 to 56.5%, and pesticide residues from tobacco into cigarette smoke were from 0.0 to 26.1% using the ISO smoking method (ISO 3308 2012).

Carbonyl Compounds in Mainstream Smoke of Hemp Cigarettes.

Introduction: CBD is a major phytocannabinoid in hemp (Cannabis sativa containing less than 0.3% THC). Hemp cigarettes are a combustible form of hemp consisting of dried and smokable flowers, which represent 2% of the overall CBD market, and the market is expected to grow. Combustion and pyrolysis of organic material are associated with the production of carbonyl compounds, which are known toxicants and are associated with adverse health outcomes. Concentrations of carbonyl compounds in mainstream hemp cigarette smoke are unknown.Materials and Methods: We analyzed and compared carbonyl concentrations in the mainstream smoke produced by a hemp cigarette (Brand B), a premium hemp cigarette (Brand A), Marlboro Red tobacco cigarette, and a research reference tobacco cigarette using high-performance liquid chromatography. We measured carbonyl concentrations in μg per puff and mg per cigarette. Carbonyls investigated were formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, 2-butanone, and butyraldehyde. Significance was determined using Tukey's test.Results: We observed that Brand B had significantly higher butyraldehyde than any cigarette. No significant differences were observed in crotonaldehyde concentration in the cigarettes. For the remaining carbonyls, Brand A had consistently lower concentrations in mainstream smoke than tobacco cigarettes. Hemp cigarettes emit carbonyls in a lower concentration in μg/puff than tobacco cigarettes, but the magnitude of significance generally decreases when normalized to mg/cigarette.Conclusions: Smoke from hemp cigarettes contains carbonyls at biologically significant concentrations. Opportunities may exist to reduce carbonyl production in these products, and identified potential risks must be considered when balancing the harms and benefits of hemp cigarettes when used for therapeutic purposes.

Robustness of HPHC Reduction in THS 2.2 Aerosol Relative to 3R4F Reference Cigarette Smoke under Extreme Climatic Conditions

Summary In order to assess robustness for the reduction of harmful and potentially harmful constituent (HPHC) levels generated by the Tobacco Heating System 2.2 (THS 2.2), a heated tobacco product, we compared the aerosol of this product with mainstream smoke from the 3R4F reference cigarette under different conditions of temperature and humidity. The desired climatic conditions were achieved by using an air-conditioning system coupled with the smoking-machine housing. Two extreme climatic conditions were selected, representing a “Hot and Dry” climate (30 °C and 35% relative humidity RH) and a “Hot and Very Humid” climate (30 °C and 75% RH). In addition, aerosol and smoke were generated using the standard conditions recognized for smoking-machine analyses of tobacco products (22 °C and 60% RH), which were close to the climatic conditions defined for “Subtropical and Mediterranean” environments (25 °C and 60% RH). The experimental conditions were chosen to simulate the use of THS 2.2 and cigarettes under extreme conditions of temperature and humidity. HeatSticks and cigarettes taken from freshly opened packs were subjected to short-term conditioning from two to a few more days under the same experimental conditions. We analyzed 54 HPHCs in THS 2.2 aerosol and 3R4F cigarette smoke, generated in accordance with the Health Canada Intense (HCI) standard, using modified temperature and humidity conditions for sample conditioning and machine-smoking experiments. We used a volume-adjusted approach for comparing HPHC reductions across the different climatic conditions investigated. Although a single puffing regimen was used, the total puff volume recorded for the 3R4F cigarette smoke varied due to the influence of temperature and humidity on combustion rate, which justified the use of a volume-adjusted approach. Volume-adjusted yields were derived from HPHC yields expressed in mass-per-tobacco stick normalized per total puff volume. The results indicated that, regardless of the considered climatic conditions, the HPHC levels investigated in THS 2.2 aerosol were reduced by at least 90%, on average, when compared with the concentrations in 3R4F cigarette mainstream smoke. This confirmed the robustness in performance for THS 2.2 to deliver reduced levels of HPHCs under the extreme climatic conditions investigated in this study. In order to further characterize the robustness of these reductions, the lowest reduction performance achieved for individual HPHCs across all climatic conditions was used to define the threshold for a robust reduction. The majority of the 54 HPHCs investigated in THS 2.2 aerosol showed more than 90% reduction. Calculations derived from nicotine-adjusted yields also confirmed robust reductions for all investigated HPHCs. The small differences in absolute reduction between the volume- and nicotine-adjusted approaches were predominantly attributed to a combination of the differences in both nominal nicotine deliveries and total puff volumes between THS 2.2 and 3R4F cigarettes; however, this did not influence the determination of robustness. Our findings confirm the value of this approach for assessing the robustness of a product’s performance under different climatic conditions.

Preconceptional smoking alters spermatozoal miRNAs of murine fathers and affects offspring\u2019s body weight

BackgroundActive smoking has been reported among 7% of teenagers worldwide, with ages ranging from 13 to 15 years. An epidemiological study suggested that preconceptional paternal smoking is associated with adolescent obesity in boys. We developed a murine adolescent smoking model before conception to investigate the paternal molecular causes of changes in offspring’s phenotype.MethodMale and female C57BL/6J mice were exposed to increasing doses of mainstream cigarette smoke (CS) from onset of puberty for 6 weeks and mated with room air (RA) controls.ResultsThirteen miRNAs were upregulated and 32 downregulated in the spermatozoa of CS-exposed fathers, while there were no significant differences in the count and morphological integrity of spermatozoa, as well as the proliferation of spermatogonia between CS- and RA-exposed fathers. Offspring from preconceptional CS-exposed mothers had lower body weights (p = 0.007). Moreover, data from offspring from CS-exposed fathers suggested a potential increase in body weight (p = 0.062).ConclusionWe showed that preconceptional paternal CS exposure regulates spermatozoal miRNAs, and possibly influences the body weight of F1 progeny in early life. The regulated miRNAs may modulate transmittable epigenetic changes to offspring, thus influence the development of respiratory- and metabolic-related diseases such as obesity, a mechanism that warrants further studies for elaborate explanations.

A 6-month inhalation toxicology study in Apoe\u2212/\u2212 mice demonstrates substantially lower effects of e-vapor aerosol compared with cigarette smoke in the respiratory tract

Cigarette smoking is the major cause of chronic obstructive pulmonary disease. Considerable attention has been paid to the reduced harm potential of nicotine-containing inhalable products such as electronic cigarettes (e-cigarettes). We investigated the effects of mainstream cigarette smoke (CS) and e-vapor aerosols (containing nicotine and flavor) generated by a capillary aerosol generator on emphysematous changes, lung function, and molecular alterations in the respiratory system of female Apoe−/− mice. Mice were exposed daily (3 h/day, 5 days/week) for 6 months to aerosols from three different e-vapor formulations—(1) carrier (propylene glycol and vegetable glycerol), (2) base (carrier and nicotine), or (3) test (base and flavor)—or to CS from 3R4F reference cigarettes. The CS and base/test aerosol concentrations were matched at 35 µg nicotine/L. CS exposure, but not e-vapor exposure, led to impairment of lung function (pressure–volume loop area, A and K parameters, quasi-static elastance and compliance) and caused marked lung inflammation and emphysematous changes, which were confirmed histopathologically and morphometrically. CS exposure caused lung transcriptome (activation of oxidative stress and inflammatory responses), lipidome, and proteome dysregulation and changes in DNA methylation; in contrast, these effects were substantially reduced in response to the e-vapor aerosol exposure. Compared with sham, aerosol exposure (carrier, base, and test) caused a slight impact on lung inflammation and epithelia irritation. Our results demonstrated that, in comparison with CS, e-vapor aerosols induced substantially lower biological and pathological changes in the respiratory tract associated with chronic inflammation and emphysema.

Determination of Free Solanesol Levels in Cigarette Filters by Liquid Chromatography-Mass Spectrometry.

Solanesol, a naturally occurring constituent of tobacco, has been utilized as a good marker for environmental tobacco smoke particulate and as a noninvasive predictor of mainstream cigarette smoke tar and nicotine intake under naturalistic smoking conditions. A fast and accurate method for measuring free solanesol to assess tobacco smoke exposure is highly desirable. We have developed and validated a new environmentally friendly, high-throughput method for measuring solanesol content in discarded cigarette filter butts. The solanesol deposited in the used filters can be correlated with mainstream smoke deliveries of nicotine and total particle matter to estimate constituent delivery to smokers. A portion of filter material is removed from cigarette butts after machine smoking, spiked with internal standard solution, extracted and quantitatively analyzed using reverse-phase liquid chromatography coupled to a triple-quadrupole mass spectrometer. The new method incorporates a 48-well plate format for automated sample preparation that reduces sample preparation time and solvent use and increases sample throughput 10-fold compared to our previous method. Accuracy and precision were evaluated by spiking known amounts of solanesol on both clean and smoked cigarette butts. Recoveries exceeded 93% at both low and high spiking levels. Linear solanesol calibration curves ranged from 1.9 to 367 µg/butt with a 0.05 µg/butt limit of detection.

Differences between cigarette smoking and biomass smoke exposure: An in silico comparative assessment of particulate deposition in the lungs

Cigarette smoking and biomass smoke are the two main environmental risk factors of chronic obstructive pulmonary disease (COPD) worldwide. However, it remains unclear why these exposures result in two different disease phenotypes. In this study, we assessed the lung deposition from biomass and cigarette smoke exposures and examined whether differences due to inherently different particle size distributions and inhalation conditions may contribute to the differences between biomass- and tobacco-related COPD phenotypes. Using high-fidelity three-dimensional computational fluid-particle dynamics in a representative upper airway geometry, coupled to one-dimensional models of the lower airways, we computed total deposited doses and examined regional deposition patterns based on exposure data from a randomized control trial in Peru and from the literature for biomass and mainstream cigarette smoke, respectively. Our results showed that intrathoracic deposition was higher in cigarette smoking, with 36.8% of inhaled biomass smoke particles and 57.7% of cigarette smoke particles depositing in the intrathoracic airways. We observed higher fractions of cigarette smoke particles in the last few airway generations, which could explain why cigarette smoking is associated with more emphysema than biomass smoke exposure. Mean daily deposited dose was two orders of magnitude higher in cigarette smoking. Lobar distributions of the deposited dose also differed, with the left lower and right upper lobes receiving the highest doses of biomass and cigarette smoke particles, respectively. Our findings suggest that the differences between biomass- and tobacco-related COPD could, at least in part, be due to differences in total and regional lung deposition of biomass and cigarette smoke.

Effect of porous corncob on the removal of HCN in cigarette mainstream smoke

In order to reduce the hydrogen cyanide (HCN) release in cigarette mainstream smoke, a new type of porous corncob (PCC) material which was different from traditional corncob-based activated carbon was prepared by a two-step chemical reaction of carboxymethylation and cupric ion complexation. Fourier Transformation Infrared Spectroscopy (FTIR) showed that the carboxymethyl group had been introduced onto the corncob, the carboxymethyl content and the cupric ion loading amount were measured. The x-ray photoelectron spectrometer (XPS) results showed that the Cu content on the surface of PCC was much higher than that of the whole material. The scanning electron microscope (SEM) and nitrogen adsorption-desorption results suggested that PCC had a porous structure. With the increase of the amounts of chloroacetic acid and sodium hydroxide in carboxymethylation reaction and the concentration of cupric ion aqueous solution in complexing reaction, the BET surface areas and pore volumes increased, while the most probable pore sizes of PCCs were close to each other. Compared with the control cigarette, the addition of PCC could effectively remove the HCN release in cigarette mainstream smoke, and the highest reduction rates of HCN per total particulate matter (TPM) was 72.4 %.

Water-Soluble Carbon Dots in Cigarette Mainstream Smoke: Their Properties and the Behavioural, Neuroendocrinological, and Neurotransmitter Changes They Induce in Mice.

BackgroundIt is well known that smoking is harmful to health; however, it can also ameliorate anxiety. To date, it is unclear whether any nanoparticles found in cigarette mainstream smoke (CS) contribute to this effect.AimThe aim of this study was to assess the particle composition of CS to identify novel anti-anxiety components.MethodsCarbon dots (CDs) from CS (CS-CDs) were characterised using high-resolution transmission electron microscopy, Fourier-transform infrared, ultraviolet, fluorescence, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. The anti-anxiety effects of CS-CDs in mouse models were evaluated and confirmed with the elevated plus maze and open-field tests.ResultsThe quantum yield of CS-CDs was 13.74%, with a composition of C, O, and N. In addition, the surface groups contained O-H, C-H, C=O, C-N, N-H, C-O-C, and COO− bonds. Acute toxicity testing revealed that CS-CDs had low in vitro and in vivo toxicity within a certain concentration range. The results of the elevated plus maze and open-field tests showed that CS-CDs had a significant anti-anxiety effect and a certain sedative effect in mice. The mechanism of these effects may be related to the decrease in glutamate levels and promotion of norepinephrine production in the mouse brain, and the decrease in dopamine in mouse serum due to CS-CDs.ConclusionCS-CDs may have anti-anxiety and certain sedative effects. This study provides a new perspective for a more comprehensive understanding of the components, properties, and functions of CS. Furthermore, it offers a novel target for the development of smoking cessation treatments, such as nicotine replacement therapy.

Quantification of nitromethane in mainstream smoke using gas chromatography and tandem mass spectrometry.

Nitromethane is a volatile organic compound categorized as a Group 2B carcinogen by the International Agency for Research on Cancer. It has been detected in mainstream cigarette smoke, but few reliable methods have been reported for accurate quantification. We developed, a sensitive, selective, fully validated method for the targeted determination of nitromethane in mainstream tobacco smoke in ten U.S. domestic brands and two quality control materials (3R4F and CM6). The vapor phase portion of machine-generated cigarette mainstream smoke, under modified ISO 3308:2000 regime (ISO) and modified intense regime (HCI), from single cigarettes was collected using airtight polyvinylfluoride sampling bags. The bags' contents were extracted using methanol containing an isotopically labeled internal standard followed by gas chromatography-tandem mass spectrometry. This approach is sufficiently sensitive to measure nitromethane levels in the nanogram range, with a method limit of detection of 72.3 ng/cig. Within-product variability estimated from the replicate analysis of 10 products ranged from 4.6%-16.3% (n = 6) over the two different smoking regimes, and method reproducibility estimated from two products used as quality control materials (3R4F and CM6) yielded intermediate precision values ranging from 16.6 to 20.8% (n = 20). Under HCI, nitromethane yields in machine-generated cigarette smoke from ten different domestic cigarette products ranged from 3.2 to 12 μg/cig; under ISO yields ranged from 1.6 to 4.9 μg/cig under standardized smoking machine conditions. Nitromethane yields are related to both the smoke regime (blocking of vent holes, puff duration and puff volume) and the heterogeneity of tobacco mixtures. This method provides a selective and fully validated technique to accurately quantify nitromethane in mainstream cigarette smoke, with minimal waste generation. It is an improvement over previous methods with regards to specificity, throughput, and simplicity of the sample collection process.

Removing tar and nicotine from mainstream cigarette smoke using sepiolite-modified filter tips

AbstractThe objective of this work was to use air-dried sepiolite granules as an additive in cigarette filter tips to increase the removal yield of tar and nicotine from mainstream smoke. Granules with a mass of 95 mg per cigarette filter and a mean particle size (D) of 0.05–0.41 mm were used to constrain the effects of the mean particle size and mass of sepiolite in the removal process. The granules were sandwiched in common cellulose acetate filter tips. Maximum removal yields of 90% were obtained when D ≤ 0.10 mm. Filters containing granules with a mean size of 0.10 mm and mass variations from 35 to 95 mg were tested, and increasing amounts of sepiolite added led to progressively greater yields of tar and nicotine from 20% to 90%. The sepiolite granules were examined using scanning electron microscopy with energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy and X-ray diffraction techniques both before and after smoke experimentation. It is suggested that tar and nicotine were condensed both on the fibre clusters of the sepiolite granules and in the voids between them during the flow of the mainstream smoke.

Nicotine Causes Nephrotoxicity through the Induction of NLRP6 Inflammasome and Alpha7 Nicotinic Acetylcholine Receptor.

Current cigarette smoking is associated with chronic kidney disease (CKD) or death from end-stage renal disease (ESRD). Mainstream cigarette smoke includes over 4000 compounds. Among the compounds present in tobacco smoke, nicotine is one of a large number of biologically stable and active compounds present in tobacco. However, the mechanisms by which nicotine exacerbates kidney disease progression have not been identified. It is known that the inflammasomes constitute an important innate immune pathway and contribute to the pathophysiology of diverse kidney diseases. The relationship between inflammasomes and nicotine-induced kidney damage still remains unclear. In the present study, we studied the mechanisms of nicotine-induced nephrotoxicity. We found that nicotine decreased cell viability and induced reactive oxygen species (ROS) generation in human kidney cells. Furthermore, nicotine significantly increased the expression of the alpha7 nicotinic acetylcholine receptor (α7nAChR). Nicotine activated the NLRP6 inflammasome and induced endoplasmic reticulum (ER) stress. Nicotine caused mild apoptosis and necrosis but triggered significant autophagy in human kidney cells. In addition, nicotine induced the NLRP6 inflammasome and autophagy via α7nAChR. In an animal model, the histological analysis in kidney showed evident changes and injury. The results indicated that α7nAChR, IRE1α, LC3 and NLRP6 expression in kidney sections was markedly increased in the nicotine groups. These findings suggest that nicotine causes kidney damage by modulating α7nAChR, NLRP6 inflammasome, ER stress and autophagy.

Tobacco Smoke and Endothelial Dysfunction: Role of Aldehydes?

Tobacco smoking is the most significant modifiable risk factor in the development of cardiovascular disease (CVD). Exposure to mainstream cigarette smoke (MCS) is associated with CVD through the development of endothelial dysfunction, a condition characterized by an imbalance of vasoactive factors in the vasculature. This dysfunction is thought to be induced in part by aldehydes generated at high levels in MCS. Electronic cigarettes (e-cigs) may also pose CVD risk. Although the health effects of e-cigs are still largely unknown, the presence of aldehydes in e-cig aerosol suggests that e-cigs may induce adverse cardiovascular outcomes similar to those seen with MCS exposure. Herein, we review studies of traditional and emerging tobacco product use, shared harmful and potentially harmful constituents, and measures of biomarkers of harm (endothelial dysfunction) to examine a potential and distinct role of aldehydes in cardiovascular harm associated with cigarette and e-cig use.

Chemosensory aerosol assessment of key attributes for tobacco products

AbstractHuman sensory evaluation plays an important role in assessing quality and supports commercial product development in many industries. However, sensory evaluation of tobacco products often requires highly trained specialists, is thus expensive, time‐consuming with low throughput capacity. To overcome such limitations, analytical platforms based on chemical fingerprints were proposed and evaluated in this work based on two different tobacco matrices. Using cigarette smoke as an example, the method was capable of predicting sensory attributes through chemical fingerprinting key tobacco and cigarette mainstream aerosol compositions. To achieve this, tobacco samples (comprising flue‐cured Virginia and air‐cured Burley types) and cigarette mainstream smoke samples were evaluated using high‐resolution mass spectrometry. The chemical fingerprint of each sample matrix was related to its respective reference sensory attributes, validated by highly trained panellists, to create predictive models based on partial least squares algorithm. These methodologies were further validated through a blind test with suitable prediction of all sensory attributes for single grade tobacco leaf and commercial blended cigarette smoke. The proposed methodology demonstrated satisfactory accuracy, repeatability and robustness, with prediction errors less than 20% for single grade tobaccos, and less than 11% for commercial products. When compared with human sensory evaluation, it significantly improved analytical capacity (over 100 samples per day) at comparable or improved accuracy. This method could be applied to evaluate other novel tobacco products such as heated tobacco products.