Mouth Level Intake of Nicotine from Three Brands of Little Filtered Cigars with Widely Differing Product Characteristics Among Adult Consumers.

Little filtered cigars are tobacco products with many cigarette-like characteristics. However, despite cigars falling under the U.S. Food and Drug Administration regulatory authority, characterizing flavors, which are still allowed in little filtered cigars, and filter design may influence how people use the products and the resulting exposure to harmful and potentially harmful constituents. We estimated nicotine mouth level intake (MLI) from analyses of little cigar filter butt solanesol levels, brand characteristics, carbon monoxide boost, and puff volume in 48 dual cigarette/cigar users during two repeat bouts of ad lib smoking of three little filtered cigar brands. Mean nicotine MLI for the three brands was significantly different with Swisher Sweets (0.1% ventilation) Cherry at 1.20 mg nicotine, Cheyenne Menthol (1.5%) at 0.63 mg, and Santa Fe unflavored (49%) at 0.94 mg. The association between nicotine MLI and puff volume was the same between Cheyenne Menthol and Santa Fe unflavored. However, these were different from Swisher Sweets Cherry. At least five main factors─flavor, ventilation, filter design, nicotine delivery related to tar, and user puff volume─may directly or indirectly impact MLI and its association with other measures. We found that users of little filtered cigars that have different filter ventilation and flavor draw dissimilar amounts of nicotine from the product, which may be accompanied by differences in exposure to other harmful smoke constituents.

From cultivation to cancer: formation of N-nitrosamines and other carcinogens in smokeless tobacco and their mutagenic implications.

Tobacco use is a major cause of preventable morbidity and mortality globally. Tobacco products, including smokeless tobacco (ST), generally contain tobacco-specific N-nitrosamines (TSNAs), such as N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK), which are potent carcinogens that cause mutations in critical genes in human DNA. This review covers the series of biochemical and chemical transformations, related to TSNAs, leading from tobacco cultivation to cancer initiation. A key aim of this review is to provide a greater understanding of TSNAs: their precursors, the microbial and chemical mechanisms that contribute to their formation in ST, their mutagenicity leading to cancer due to ST use, and potential means of lowering TSNA levels in tobacco products. TSNAs are not present in harvested tobacco but can form due to nitrosating agents reacting with tobacco alkaloids present in tobacco during certain types of curing. TSNAs can also form during or following ST production when certain microorganisms perform nitrate metabolism, with dissimilatory nitrate reductases converting nitrate to nitrite that is then released into tobacco and reacts chemically with tobacco alkaloids. When ST usage occurs, TSNAs are absorbed and metabolized to reactive compounds that form DNA adducts leading to mutations in critical target genes, including the RAS oncogenes and the p53 tumor suppressor gene. DNA repair mechanisms remove most adducts induced by carcinogens, thus preventing many but not all mutations. Lastly, because TSNAs and other agents cause cancer, previously documented strategies for lowering their levels in ST products are discussed, including using tobacco with lower nornicotine levels, pasteurization and other means of eliminating microorganisms, omitting fermentation and fire-curing, refrigerating ST products, and including nitrite scavenging chemicals as ST ingredients.

Hydrogen Cyanide and Aromatic Amine Yields in the Mainstream Smoke of 60 Little Cigars.

Mainstream smoke yields of hydrogen cyanide (HCN) and three aromatic amines, 1-aminonaphthalene, 2-aminonaphthalene, and 4-aminobiphenyl, from 60 little cigar brands currently on the US market were measured for both International Organization for Standardization (ISO) and Canadian Intense (CI) smoking regimens. The smoke yields are compared with those from 50 cigarette products measured by Counts et al. of Philip Morris USA (PMUSA) in 2005 [Counts et al. Regul. Toxicol. Pharmacol. 2005 41, 185-227] and 50 cigarette products measured by the Centers for Disease Control and Prevention (CDC) in cooperation with the Food and Drug Administration (FDA) in 2012 [Tynan et al. Consumption of Cigarettes and Combustible Tobacco: United States, 2000-2011. In Morbidity and Mortality Weekly Report; Centers for Disease Control and Prevention, 2012; 565-580]. For the little cigars, the average HCN yield with the ISO smoking regimen is 335 µg/cigar (range: 77-809 µg/cigar), which is 332% higher than the average of 50 PMUSA 2005 cigarettes and 243% higher than the average of 50 CDC/FDA 2012 cigarettes. For the CI smoking regimen, the average HCN yield is 619 µg/cigar (range: 464-1045 µg/cigar), which is 70.5% higher than the average of 50 PMUSA 2005 cigarettes and 69% higher than the average of the 50 CDC/FDA 2012 cigarettes. For aromatic amines, the average ISO smoking regimen smoke yields are 36.6 ng/cigar (range: 15.9-70.6 ng/cigar) for 1-aminonaphthalene, 24.6 ng/cigar (range: 12.3-36.7 ng/cigar) for 2-aminonaphthalene, and 5.6 ng/cigar (range: 2.3-17.2 ng/cigar) for 4-aminobiphenyl. The average ISO yields of aromatic amines from little cigars are 141% to 210% higher compared to the average yields of 50 PMUSA cigarettes. The average CI smoke regimen yields are 73.0 ng/cigar (range: 32.1-112.2 ng/cigar) for 1-aminonaphthalene, 45.2 ng/cigar (range: 24.6-74.8 ng/cigar) for 2-aminonaphthalene, and 12.7 ng/cigar (range: 5.5-37.5 ng/cigar) for 4-aminobiphenyl. The average CI aromatic amine yields are 143% to 220% higher compared to the average yields of 50 PMUSA cigarettes, almost identical to the relative yields under the ISO smoking regimen. Both HCN and aromatic amine yields are 1.5× to 3× higher for the tested little cigars than for the conventional cigarettes; however, there are notable differences in the relationships of these yields to certain product characteristics, such as weight, ventilation, and tobacco type. The higher smoke yields of these compounds from little cigars indicates that cigar smokers may be at risk of a higher exposure to HCN and aromatic amines on a per stick basis and thus increased health concerns.

Comparison of Mainstream Smoke Yields between Linear and Rotary Smoking Machines and Evaluation of "Super Pad" Extraction for Linear Smoking Machines.

Two-tail t test statistical analyses of International Organization for Standardization nonintense and Canadian Intense mainstream smoke yields of total particulate matter, tar, nicotine, and carbon monoxide from cigarettes show that mean quantities are generally higher for a linear smoking machine at a 95% confidence level but a rotary smoking machine has better precision. A novel "super pad" analysis concept combines four smaller filter pads from a linear smoking machine, resulting in increased mean constituent yields and reduced variability. Although measurement variability is still greater than that of rotary machines, super padding may be useful to reduce the variance caused by linear smoking machines.

Measurement of the Free-Base Nicotine Fraction (αfb) in Electronic Cigarette Liquids by Headspace Solid-Phase Microextraction.

A method for determining the fraction of free-base nicotine (αfb) in electronic cigarette liquids ("e-liquids") based on headspace solid-phase microextraction (h-SPME) is described. The free-base concentration ce,fb = αfbce,T, where ce,T is the total (free-base + protonated) nicotine in the liquid. For gas/liquid equilibrium of the volatile free-base form, the headspace nicotine concentration is proportional to ce,fb and thus also to αfb. Headspace nicotine is proportionally absorbed with an SPME fiber. The fiber is thermally desorbed in the heated inlet of a gas chromatograph coupled to a mass spectrometer: the desorbed nicotine is measured by gas chromatography-mass spectrometry. For a second h-SPME measurement, an adequate base is added to the sample vial to convert essentially all protonated nicotine to the free-base form (αfb → 1.0). The ratio of the first h-SPME measurement to the second h-SPME measurement gives αfb in the initial sample. Using gaseous ammonia as the added base, the method was (1) verified using lab-prepared e-liquid solutions with known αfb values and (2) used to determine the αfb values for 18 commercial e-liquids. The measured αfb values ranged from 0.0 to 1.0. Increasing measurement error with decreasing αfb caused modestly lower method precision at small αfb. Adding a liquid organic base may be more convenient than adding gaseous ammonia: one of the samples was examined using triethylamine as the added base; the measurements agreed well (with ammonia, 0.27 ± 0.01; with triethylamine, 0.26 ± 0.04). Other workers have proposed examining the nicotine protonation state in e-liquids using three steps: (1) 1:10 dilution with CO2-free water; (2) measurement of pH; and (3) calculation of the resulting values for αfb,w,1:10, the free-base fraction in the diluted mostly aqueous phase. As expected and verified here, because of the generally greater abilities of organic acids to protonate nicotine in water versus in an e-liquid phase, αfb,w,1:10 values can be significantly less than actual e-liquid αfb values when αfb is not close to either 0 or 1.

Volatile Organic Compounds in Mainstream Smoke of Sixty Domestic Little Cigar Products.

The mainstream smoke yields of five volatile organic compounds (VOCs) were determined from 60 commercial U.S. little cigar products under ISO 3308 and Canadian Intense (CI) smoking regimens on linear smoking machines using a gas sampling bag collection. The five VOCs, 1,3-butadiene, acrylonitrile, benzene, isoprene, and toluene were analyzed using an automated GC/MS analytical method validated for measuring various VOCs in mainstream smoke. The VOCs range in amounts from micrograms to milligrams per little cigar. VOC deliveries vary considerably among the little cigar products under the ISO smoking regimen primarily due to varying filter ventilation. Under the CI smoking regimen where filter ventilation is blocked, the delivery range narrows, although individual and total VOC yields are approximately 2 fold higher than those under the ISO smoking regimen. Correlation analysis reveals strong associations between acrylonitrile and 1,3-butadiene or toluene under the ISO smoking regimen. Compared to cigarettes, little cigars delivered substantially higher VOC mainstream smoke yields under both ISO and CI smoking regimens. Moreover, little cigar smoke also contains higher VOCs than cigarette smoke when adjusted for mass of tobacco.

Tobacco-Specific Nitrosamines in the Tobacco and Mainstream Smoke of Commercial Little Cigars.

Cigars are among the broad variety of tobacco products that have not been as extensively studied and characterized as cigarettes. Small cigars wrapped in a tobacco-containing sheet, commonly referred to as little cigars, are a subcategory that are similar to conventional cigarettes with respect to dimensions, filters, and overall appearance. Tobacco-specific nitrosamines (TSNAs) are carcinogens in the tobacco used in both little cigars and cigarettes. This study uses a validated high-performance liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) method to measure the TSNAs 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) in the tobacco filler and the nonintense International Organization for Standardization smoking regimen, ISO 3308, and the newer ISO 20778 Cigarette Intensive (CI) smoking regimen mainstream smoke of 60 commercial little cigars. Tobacco filler NNK and NNN quantities ranged from 26 to 2950 and 1440 to 12 100 ng/g tobacco, respectively. NNK and NNN by the ISO nonintense smoking regimen ranged from 89 to 879 and 200 to 1540 ng/cigar, respectively; by the CI regimen, NNK and NNN ranged from 138 to 1570 and 445 to 2780 ng/cigar, respectively. The average transfer (%) for NNK and NNN from tobacco filler to mainstream smoke was 24% and 36% by the ISO nonintense and CI smoking regimens, respectively. By the ISO nonintense and CI smoking regimens, mainstream smoke NNK and NNN yields showed a moderate to strong correlation (ISO nonintense, R2 = 0.60-0.68, p < 0.0001; CI, R2 = 0.78-0.81, p < 0.0001) with tobacco filler NNK and NNN quantities. In addition, the mainstream smoke NNK and NNN yields of little cigars were determined to be 3- to 5-fold higher compared to previously tested commercial cigarettes. The mainstream smoke NNK and NNN yields have wide variation among commercial little cigars and suggest that, despite design similarities to cigarettes, machine-smoke yields of carcinogenic TSNAs are higher in little cigars.

PhenX: Agent measures for tobacco regulatory research.

The current paper describes the PhenX (Phenotypes and eXposures) Toolkit Tobacco Regulatory Research Agent specialty area and the Agent Working Group's (WG's) 6-month consensus process to identify high-priority, scientifically supported measures for cross-study comparison and analysis. Eleven measures were selected for inclusion in the Toolkit. Eight of these are interviewer-administered or self-administered protocols: history of switching to lower tar and nicotine cigarettes, passive exposures to tobacco products, tobacco brand and variety (covering cigars, cigarettes and smokeless tobacco separately), tobacco product adulteration (vent-blocking or filter-blocking) and tobacco warning label exposure and recall. The remaining three protocols are either laboratory-based or visual inspection-based: measurement of nicotine content in smoked or smokeless tobacco products and the physical properties of these two classes of products. Supplemental protocols include a biomarker of exposure and smoking topography. The WG identified the lack of standard measurement protocols to assess subjective ratings of tobacco product flavours and their appeal to consumers as a major gap. As the characteristics of tobacco products that influence perception and use are tobacco regulatory research priorities, the reliable assessment of flavours remains an area requiring further development.

Trends in Manufacturer-Reported Nicotine Yields in Cigarettes Sold in the United States, 2013-2016.

INTRODUCTION: A gradual reduction of cigarette nicotine content to nonaddictive levels has been proposed as an endgame strategy to accelerate declines in combustible tobacco smoking. We assessed manufacturer-reported nicotine yield in cigarettes sold in the United States from 2013 to 2016. METHODS: We merged machine-measured nicotine yield in cigarette smoke and pack characteristics obtained from reports filed by tobacco manufacturers with the Federal Trade Commission for 2013-2016 with monthly Nielsen data on US cigarette sales. Manufacturer-reported, sales-weighted, average annual nicotine yield was assessed, as were nicotine yield sales trends by quartile: markedly low (0.10-0.60 mg/stick), low (0.61-0.80 mg/stick), moderate (0.81-0.90 mg/stick), and high (0.91-3.00 mg/stick). Trends in overall, menthol, and nonmenthol pack sales, by nicotine yield quartiles over the study period and by year, were determined by using Joinpoint regression. RESULTS: During 2013-2016, average annual sales-weighted nicotine yield for all cigarettes increased from 0.903 mg/stick (95% CI, 0.882-0.925) in 2013 to 0.938 mg/stick (95% CI, 0.915-0.962) in 2016 (P < .05). For menthol cigarettes, yield increased from 0.943 mg/stick in 2013 (95% CI, 0.909-0.977) to 1.037 mg/stick in 2016 (95% CI, 0.993-1.081), increasing 0.2% each month (P < .05). Most pack sales occurred among high (41.5%) and low (30.7%) nicotine yield quartiles. Cigarette sales for the markedly low quartile decreased by an average of 0.4% each month during 2013-2016 (P < .05). CONCLUSION: During 2013-2016, manufacturer-reported, sales-weighted nicotine yield in cigarettes increased, most notably for menthol cigarettes. Continued monitoring of nicotine yield and content in cigarettes can inform tobacco control strategies.

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.

Caffeine Concentrations in Coffee, Tea, Chocolate, and Energy Drink Flavored E-liquids.

INTRODUCTION: Most electronic cigarettes (e-cigarettes) contain a solution of propylene glycol/glycerin and nicotine, as well as flavors. E-cigarettes and their associated e-liquids are available in numerous flavor varieties. A subset of the flavor varieties include coffee, tea, chocolate, and energy drink, which, in beverage form, are commonly recognized sources of caffeine. Recently, some manufacturers have begun marketing e-liquid products as energy enhancers that contain caffeine as an additive. METHODS: A Gas Chromatography-Mass Spectrometry (GC-MS) method for the quantitation of caffeine in e-liquids was developed, optimized and validated. The method was then applied to assess caffeine concentrations in 44 flavored e-liquids from cartridges, disposables, and refill solutions. Products chosen were flavors traditionally associated with caffeine (ie, coffee, tea, chocolate, and energy drink), marketed as energy boosters, or labeled as caffeine-containing by the manufacturer. RESULTS: Caffeine was detected in 42% of coffee-flavored products, 66% of tea-flavored products, and 50% of chocolate-flavored e-liquids (limit of detection [LOD] - 0.04 µg/g). Detectable caffeine concentrations ranged from 3.3 µg/g to 703 µg/g. Energy drink-flavored products did not contain detectable concentrations of caffeine. Eleven of 12 products marketed as energy enhancers contained caffeine, though in widely varying concentrations (31.7 µg/g to 9290 µg/g). CONCLUSIONS: E-liquid flavors commonly associated with caffeine content like coffee, tea, chocolate, and energy drink often contained caffeine, but at concentrations significantly lower than their dietary counterparts. Estimated daily exposures from all e-cigarette products containing caffeine were much less than ingestion of traditional caffeinated beverages like coffee. IMPLICATIONS: This study presents an optimized and validated method for the measurement of caffeine in e-liquids. The method is applicable to all e-liquid matrices and could potentially be used to ensure regulatory compliance for those geographic regions that forbid caffeine in e-cigarette products. The application of the method shows that caffeine concentrations and estimated total caffeine exposure from e-cigarette products is significantly lower than oral intake from beverages. However, because very little is known about the effects of caffeine inhalation, e-cigarette users should proceed with caution when using caffeine containing e-cigarette products. Further research is necessary to determine associated effects from inhaling caffeine.

In Situ Derivatization and Quantification of Seven Carbonyls in Cigarette Mainstream Smoke.

Carbonyls, especially aldehydes, are a group of harmful volatile organic compounds that are found in tobacco smoke. Seven carbonyls are listed on the FDA's harmful and potential harmful constituents list for tobacco or tobacco smoke. Carbonyls have reactive functional groups and thus are challenging to quantitatively measure in cigarette smoke. The traditional method of measuring carbonyls in smoke involves solvent-filled impinger trapping and derivatization. This procedure is labor-intensive and generates significant volumes of hazardous waste. We have developed a new method to efficiently derivatize and trap carbonyls from mainstream smoke in situ on Cambridge filter pads. The derivatized carbonyls are extracted from the pads and subsequently quantified by ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry. The new method has been validated and applied to research and commercial cigarettes. Carbonyl yields from research cigarettes are comparable to those from other published literature data. With a convenient smoke collection apparatus, a 4 min sample analysis time, and a low- or submicrogram detection limit, this new method not only simplifies and speeds the detection of an important class of chemical constituents in mainstream smoke but also reduces reactive losses and provides a more accurate assessment of carbonyl levels in smoke. Excellent accuracy (average 98%) and precision (14% average relative standard deviation in research cigarettes) ensure this new method's sufficient fidelity to characterize conventional combusted tobacco products, with potential application toward new or emerging products.

Menthol Content in US Marketed Cigarettes.

INTRODUCTION: In 2011 menthol cigarettes accounted for 32 percent of the market in the United States, but there are few literature reports that provide measured menthol data for commercial cigarettes. To assess current menthol application levels in the US cigarette market, menthol levels in cigarettes labeled or not labeled to contain menthol was determined for a variety of contemporary domestic cigarette products. METHOD: We measured the menthol content of 45 whole cigarettes using a validated gas chromatography/mass spectrometry method. RESULTS: In 23 cigarette brands labeled as menthol products, the menthol levels of the whole cigarette ranged from 2.9 to 19.6mg/cigarette, with three products having higher levels of menthol relative to the other menthol products. The menthol levels for 22 cigarette products not labeled to contain menthol ranged from 0.002 to 0.07mg/cigarette. The type of packaging (soft vs. hard pack) for a given cigarette product does not appear to affect menthol levels based on the current limited data. CONCLUSIONS: Menthol levels in cigarette products labeled as containing menthol are approximately 50- to 5000-fold higher than those in cigarette products not labeled as containing menthol. In general, menthol content appears to occur within discrete ranges for both mentholated and nonmentholated cigarettes. IMPLICATIONS: This study shows that menthol may be present in non-mentholated cigarettes and adds to the understanding of how menthol may be used in cigarette products. It is the first systematic study from the same laboratory which will readily enable comparison among menthol and non-menthol cigarettes.

Mainstream Smoke Levels of Volatile Organic Compounds in 50 U.S. Domestic Cigarette Brands Smoked With the ISO and Canadian Intense Protocols.

INTRODUCTION: A significant portion of the increased risk of cancer and respiratory disease from exposure to cigarette smoke is attributed to volatile organic compounds (VOCs). In this study, 21 VOCs were quantified in mainstream cigarette smoke from 50U.S. domestic brand varieties that included high market share brands and 2 Kentucky research cigarettes (3R4F and 1R5F). METHODS: Mainstream smoke was generated under ISO 3308 and Canadian Intense (CI) smoking protocols with linear smoking machines with a gas sampling bag collection followed by solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) analysis. RESULTS: For both protocols, mainstream smoke VOC amounts among the different brand varieties were strongly correlated between the majority of the analytes. Overall, Pearson correlation (r) ranged from 0.68 to 0.99 for ISO and 0.36 to 0.95 for CI. However, monoaromatic compounds were found to increase disproportionately compared to unsaturated, nitro, and carbonyl compounds under the CI smoking protocol where filter ventilation is blocked. CONCLUSIONS: Overall, machine generated "vapor phase" amounts (µg/cigarette) are primarily attributed to smoking protocol (e.g., blocking of vent holes, puff volume, and puff duration) and filter ventilation. A possible cause for the disproportionate increase in monoaromatic compounds could be increased pyrolysis under low oxygen conditions associated with the CI protocol. IMPLICATIONS: This is the most comprehensive assessment of volatile organic compounds (VOCs) in cigarette smoke to date, encompassing 21 toxic VOCs, 50 different cigarette brand varieties, and 2 different machine smoking protocols (ISO and CI). For most analytes relative proportions remain consistent among U.S. cigarette brand varieties regardless of smoking protocol, however the CI smoking protocol did cause up to a factor of 6 increase in the proportion of monoaromatic compounds. This study serves as a basis to assess VOC exposure as cigarette smoke is a principle source of overall population-level VOC exposure in the United States.

Polycyclic Aromatic Hydrocarbons in the Mainstream Smoke of Popular U.S. Cigarettes.

The mainstream smoke yields of 14 polycyclic aromatic hydrocarbons (PAHs) were determined for 50 commercial U.S. cigarettes using a validated GC/MS method with the International Organization of Standardization (ISO) and Canadian Intense (CI) smoking machine regimens. PAH mainstream smoke deliveries vary widely among the commercial cigarettes with the ISO smoking regimen primarily because of differing filter ventilation. The more abundant, lower molecular weight PAHs such as naphthalene, fluorene, and phenanthrene predominantly comprise the total PAH yields. In contrast, delivery yields of high molecular weight PAHs such as benzo[b]fluoranthene, benzo[e]pyrene, benzo[k]fluoranthene, and benzo[a]pyrene (BaP) are much lower. Comparative analysis of PAHs deliveries shows brand specific differences. Correlation analysis shows strong positive associations between BaP and most of the other PAHs as well as total PAHs. The results suggest that BaP may be a representative marker for other PAH constituents in cigarette smoke generated from similarly blended tobacco, particularly those PAHs with similar molecular weights and chemical structures.

A High Throughput Method for Estimating Mouth-Level Intake of Mainstream Cigarette Smoke.

INTRODUCTION: We developed a high throughput method for estimating smoker's mainstream smoke intake on a per-cigarette basis by analyzing discarded cigarette butts. This new method utilizes ultraviolet/visible (UV-Vis) spectrophotometric analysis of isopropanol-soluble smoke particulate matter extracted from discarded cigarette filters. METHODS: When measured under a wide range of smoking conditions for a given brand variant, smoking machine delivery of nicotine, benzene, polycyclic aromatic hydrocarbons, and tobacco-specific nitrosamines can be related to the overall filter extract absorbance at 360 nm. Once this relationship has been established, UV-Vis analysis of a discarded cigarette filter butt gives a quantitative measure of a smoker's exposure to these analytes. RESULTS: The measured mainstream smoke constituents correlated closely (correlation coefficients from 0.9303 to 0.9941) with the filter extract absorbance. These high correlations held over a wide range of smoking conditions for 2R4F research cigarettes as well as popular domestic cigarette brands sold in the United States. CONCLUSIONS: This low cost, high throughput method is suitable for high volume analyses (hundreds of samples per day) because UV-Vis spectrophotometry, rather than mass spectrometry, is used for the cigarette filter butt analysis. This method provides a stable and noninvasive means for estimating mouth-level delivery of many mainstream smoke constituents. The ability to gauge the mouth-level intake of harmful chemicals and total mainstream smoke for cigarette smokers in a natural setting on a cigarette-by-cigarette basis can provide insights on factors contributing to morbidity and mortality from cigarette smoking, as well as insights on strategies related to smoking cessation.

Chemical Composition and Evaluation of Nicotine, Tobacco Alkaloids, pH, and Selected Flavors in E-Cigarette Cartridges and Refill Solutions.

INTRODUCTION: Electronic cigarette (e-cigarette) use is increasing dramatically in developed countries, but little is known about these rapidly evolving products. This study analyzed and evaluated the chemical composition including nicotine, tobacco alkaloids, pH, and flavors in 36 e-liquids brands from 4 manufacturers. METHODS: We determined the concentrations of nicotine, alkaloids, and select flavors and measured pH in solutions used in e-cigarettes. E-cigarette products were chosen based upon favorable consumer approval ratings from online review websites. Quantitative analyses were performed using strict quality assurance/quality control validated methods previously established by our lab for the measurement of nicotine, alkaloids, pH, and flavors. RESULTS: Three-quarters of the products contained lower measured nicotine levels than the stated label values (6%-42% by concentration). The pH for e-liquids ranged from 5.1-9.1. Minor tobacco alkaloids were found in all samples containing nicotine, and their relative concentrations varied widely among manufacturers. A number of common flavor compounds were analyzed in all e-liquids. CONCLUSIONS: Free nicotine levels calculated from the measurement of pH correlated with total nicotine content. The direct correlation between the total nicotine concentration and pH suggests that the alkalinity of nicotine drives the pH of e-cigarette solutions. A higher percentage of nicotine exists in the more absorbable free form as total nicotine concentration increases. A number of products contained tobacco alkaloids at concentrations that exceed U.S. pharmacopeia limits for impurities in nicotine used in pharmaceutical and food products.

Method for the determination of ammonium in cigarette tobacco using ion chromatography.

Ammonia and other alkaline substances have been postulated to be important in cigarette design. The most significant potential contribution of ammonia is a possible interaction with the native, protonated nicotine in the smoke. Ammonia is more alkaline than nicotine and could facilitate a shift in the acid/base equilibrium where a fraction of the total nicotine converts to the more lipophilic, non-protonated form. This non-protonated, or free-base, form of nicotine absorbs more efficiently across membranes, resulting in more rapid delivery to the smoker's bloodstream. Ammonia and other potential ammonia sources, such as additives like diammonium phosphate, could influence the acid-base dynamics in cigarette smoke and ultimately the rate of nicotine delivery. To examine and characterize the ammonia content in modern cigarettes, we developed a fast, simple and reliable ion chromatography based method to measure extractable ammonia levels in cigarette filler. This approach has minimal sample preparation and short run times to achieve high sample throughput. We quantified ammonia levels in tobacco filler from 34 non-mentholated cigarette brands from 3 manufacturers to examine the ranges found across a convenience sampling of popular, commercially available domestic brands and present figures of analytical merit here. Ammonia levels ranged from approximately 0.9 to 2.4mg per gram of cigarette filler between brands and statistically significance differences were observed between brands and manufacturers. Our findings suggest that ammonia levels vary by brand and manufacturer; thus in domestic cigarettes ammonia could be considered a significant design feature because of the potential influence on smoke chemistry.

Simultaneous analysis of 22 volatile organic compounds in cigarette smoke using gas sampling bags for high-throughput solid-phase microextraction.

Quantifying volatile organic compounds (VOCs) in cigarette smoke is necessary to establish smoke-related exposure estimates and evaluate emerging products and potential reduced-exposure products. In response to this need, we developed an automated, multi-VOC quantification method for machine-generated, mainstream cigarette smoke using solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS). This method was developed to simultaneously quantify a broad range of smoke VOCs (i.e., carbonyls and volatiles, which historically have been measured by separate assays) for large exposure assessment studies. Our approach collects and maintains vapor-phase smoke in a gas sampling bag, where it is homogenized with isotopically labeled analogue internal standards and sampled using gas-phase SPME. High throughput is achieved by SPME automation using a CTC Analytics platform and custom bag tray. This method has successfully quantified 22 structurally diverse VOCs (e.g., benzene and associated monoaromatics, aldehydes and ketones, furans, acrylonitrile, 1,3-butadiene, vinyl chloride, and nitromethane) in the microgram range in mainstream smoke from 1R5F and 3R4F research cigarettes smoked under ISO (Cambridge Filter or FTC) and Intense (Health Canada or Canadian Intense) conditions. Our results are comparable to previous studies with few exceptions. Method accuracy was evaluated with third-party reference samples (≤15% error). Short-term diffusion losses from the gas sampling bag were minimal, with a 10% decrease in absolute response after 24 h. For most analytes, research cigarette inter- and intrarun precisions were ≤20% relative standard deviation (RSD). This method provides an accurate and robust means to quantify VOCs in cigarette smoke spanning a range of yields that is sufficient to characterize smoke exposure estimates.