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 four 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 (QC) 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.

Objective To provide researchers an extensive characterization of the SPECTRUM variable nicotine research cigarettes. Methods Data on cigarette physical properties, nicotine content, harmful and potentially harmful constituents in the tobacco filler was compiled. Results Data on physical properties, concentrations of menthol, nicotine and minor alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, ammonia, and toxic metals in the filler tobacco for all available varieties of Spectrum research cigarettes are provided. The similarity in the chemistry and physical properties of SPECTRUM cigarettes to commercial cigarettes renders them acceptable for use in behavioral studies. Baseline information on harmful and potentially harmful constituents in research tobacco products, particularly constituent levels such as minor alkaloids that fall outside typical ranges reported for commercial, provide researchers with the opportunity to monitor smoking behavior and to identify biomarkers that will inform efforts to understand the role of nicotine in creating and sustaining addiction. Conclusions Well characterized research cigarettes suitable for human consumption are an important tool in clinical studies for investigating the physiological impacts of cigarettes delivering various levels of nicotine, the impact of reduced nicotine cigarettes on nicotine addiction, and the relationship between nicotine dose and smoking behavior.

Introduction Nicotine pouch products, oral smokeless products that contain nicotine but no tobacco leaf material, have recently entered the US marketplace. Available data indicate sales of these products in the United States have increased since 2018; however, the extent of use among US youth and adults is uncertain. Methods To assay the chemistry of these emerging tobacco products, we analyzed 37 nicotine pouch brands from six total manufacturers. Almost all of the products had flavor descriptors (36 of 37), such as mint, licorice, coffee, cinnamon, and fruit. The amount of free nicotine, the form most easily absorbed, was calculated for each product using total nicotine, product pH, the appropriate pKa, and the Henderson–Hasselbalch equation. Results Nicotine pouch products varied in pouch content mass, moisture content (1.12%‒47.2%), alkalinity (pH 6.86‒10.1), and % free nicotine (7.7%‒99.2%). Total nicotine content ranged from 1.29 to 6.11 mg/pouch, whereas free nicotine ranged from 0.166 to 6.07 mg/pouch. These findings indicate that nicotine and pH levels found in some of these nicotine pouches are similar to conventional tobacco products, such as moist snuff and snus, and that most of these pouch products are flavored. Conclusions Although these products likely lack many tobacco-related chemicals, each product analyzed contained nicotine, which is both addictive and can harm human health. Given that nicotine pouches may appeal to a spectrum of users, from novice to experienced users, it is important to include these emerging tobacco products in tobacco control research, policy, and practice. Implications These “tobacco-free” nicotine pouches have similar pH and nicotine content to conventional tobacco products, such as moist snuff and snus. Although they lack many tobacco-related chemicals, most are highly flavored which could increase experimentation from new users. Given that nicotine pouches may appeal to a spectrum of users, from novice to experienced users, in terms of their flavors and nicotine content, it is important to examine and include these emerging tobacco products as they relate to tobacco control research, policy, and practice.

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 U.S. 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 45whole cigarettes using a validated gas chromatography/mass spectrometry method (GC/MS). Results In 23 cigarette brands labeled as menthol products, the menthol levels of the whole cigarette ranged from 2.9 to 19.6 mg/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 0.07 mg/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. Conclusion Menthol levels in cigarette products labeled as containing menthol are approximately 50 to 5,000-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 non-mentholated cigarettes.