Last data update: Sep 23, 2024. (Total: 47723 publications since 2009)
Records 1-13 (of 13 Records) |
Query Trace: Lisko JG [original query] |
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Correction: Menthol levels in cigarettes from eight manufacturers
Ai J , Taylor KM , Lisko JG , Tran H , Watson CH , Holman MR . Tob Control 12/28/2021 30 e173-e175 The research letter “Menthol levels in cigarettes from eight manufacturers” reports concentrations of menthol in whole cigarettes from eight manufacturers in the United States. As our research has progressed, we have re-examined our results and have identified an error in the calculations that were used to determine the reported menthol concentrations. The analytical method used to quantitate menthol concentrations in whole cigarettes was originally developed for only unburned tobacco (eg, tobacco filler). When the method was applied to whole cigarettes, we discovered that we did not account for the mass of the tobacco (400 mg) that was used in the validation of the analytical method. Because the calibration curve originally used to quantitate menthol concentrations has units of μg/g, the cigarette mass was also applied incorrectly. As a result, the calibration curve and subsequent product menthol concentrations quantitated under the original conditions in μg/g should have been adjusted by a factor of 0.4 to provide the correct concentration of menthol found in each cigarette product (μg/cig). Figure 1, has been revised to reflect the correct menthol concentrations from the different manufacturers. Table 1 contains the measured menthol concentration ranges for each manufacturer so that readers can see the measured menthol concentrations used to create figure 1. Because the calculation error applies to all products, relative concentration comparisons made in the manuscript between products remain unchanged. | |
Chemical analysis of snus products from the United States and northern Europe
Lawler TS , Stanfill SB , Tran HT , Lee GE , Chen PX , Kimbrell JB , Lisko JG , Fernandez C , Caudill SP , deCastro BR , Watson CH . PLoS One 2020 15 (1) e0227837 INTRODUCTION: Snus is an oral tobacco product that originated in Sweden. Snus products are available as fine-cut loose tobacco or in pre-portioned porous "pouches." Some snus products undergo tobacco pasteurization during manufacturing, a process that removes or reduces nitrite-forming microbes, resulting in less tobacco-specific nitrosamine content in the product. Some tobacco companies and researchers have suggested that snus is potentially less harmful than traditional tobacco and thus a potential smoking cessation aid or an alternative to continued cigarette consumption. Although snus is available in various countries, limited information exists on snus variants from different manufacturers. METHODS: Moisture, pH, nicotine, and tobacco-specific N'-nitrosamines (TSNAs) were quantified in 64 snus products made by 10 manufacturers in the United States and Northern Europe (NE). Reported means, standard errors, and differences are least-square (LS) estimates from bootstrapped mixed effects models, which accounted for correlation among repeated measurements. Minor alkaloids and select flavors were also measured. RESULTS: Among all product types, moisture (27.4%-59.5%), pH (pH 5.87-9.10), total nicotine (6.81-20.6 mg/g, wet), unprotonated nicotine (0.083-15.7 mg/g), and total TSNAs (390-4,910 ng/g) varied widely. The LS-mean unprotonated nicotine concentration of NE portion (7.72 mg/g, SE = 0.963) and NE loose (5.06 mg/g, SE = 1.26) snus were each significantly higher than US portion snus (1.00 mg/g, SE = 1.56). Concentrations of minor alkaloids varied most among products with the highest total nicotine levels. The LS-mean NNN+NNK were higher in snus sold in the US (1360 ng/g, SE = 207) than in NE (836 ng/g, SE = 132) countries. The most abundant flavor compounds detected were pulegone, eucalyptol, and menthol. CONCLUSION: Physical and chemical characteristics of US and NE products labeled as snus can vary considerably and should not be considered "equivalent". Our findings could inform public health and policy decisions pertaining to snus exposure and potential adverse health effects associated with snus. |
Chemical characterization of smokeless tobacco products from South Asia: Nicotine, unprotonated nicotine, tobacco-specific N-Nitrosamines, and flavor compounds
Stanfill SB , Croucher RE , Gupta PC , Lisko JG , Lawler TS , Kuklenyik P , Dahiya M , Duncan B , Kimbrell JB , Peuchen EH , Watson CH . Food Chem Toxicol 2018 118 626-634 Certain South Asian smokeless tobacco, including ready-to-use products, are not well characterized. | | • | In this study, we measured pH and concentrations of nicotine, tobacco-specific nitrosamines, and flavor compounds. | | • | Products had a wide range of moisture (4.0–46.6%), pH (pH 4.99–10.0), total nicotine (0.39–35.2 mg/g) and unprotonated nicotine (<0.01–11.9 mg/g). | | • | Two khaini products analyzed contained higher levels of N′-Nitrosonornicotine, a compound associated with oral cancer. | | • | Understanding the constituents in these products is necessary for characterizing potential harm as these products become more available worldwide. |
Surveillance of nicotine and pH in cigarette and cigar filler
Lawler TS , Stanfill SB , deCastro BR , Lisko JG , Duncan BW , Richter P , Watson CH . Tob Regul Sci 2017 3 101-116 OBJECTIVE: We examined differences between nicotine concentrations and pH in cigarette and cigar tobacco filler. METHODS: Nicotine and pH levels for 50 cigarette and 75 cigar brands were measured. Non-mentholated and mentholated cigarette products were included in the analysis along with several cigar types as identified by the manufacturer: large cigars, pipe tobacco cigars, cigarillos, mini cigarillos, and little cigars. RESULTS: There were significant differences found between pH and nicotine for cigarette and cigar tobacco products. Mean nicotine concentrations in cigarettes (19.2 mg/g) and large cigars (15.4 mg/g) were higher than the other cigars types, especially the pipe tobacco cigars (8.79 mg/g). The mean pH for cigarettes was pH 5.46. Large cigars had the highest mean pH value (pH 6.10) and pipe tobacco cigars had the lowest (pH 5.05). CONCLUSIONS: Although cigarettes are the most common combustible tobacco product used worldwide, cigar use remains popular. Our research provides a means to investigate the possibility of distinguishing the 2 tobacco product types and offers information on nicotine and pH across a wide range of cigarette and cigar varieties that may be beneficial to help establish tobacco policies and regulations across product types. |
Development of a cigarette tobacco filler standard reference material
Sander LC , Pritchett JS , Daniels YC , Wood LJ , Lang BE , Wise SA , Yen JH , Johnson TL , Walters MJ , Phillips T , Holman MR , Lee GE , Lisko JG , Lane B , Valentin-Blasini L , Watson C . Anal Chem 2017 89 (19) 10461-10467 A new tobacco filler Standard Reference Material (SRM) has been issued by the National Institute of Standards and Technology (NIST) in September 2016 with certified and reference mass fraction values for nicotine, N-nitrosonornicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, and volatiles. The constituents have been determined by multiple analytical methods with measurements at NIST and at the Centers for Disease Control and Prevention, and with confirmatory measurements by commercial laboratories. This effort highlights the development of the first SRM for reduced nicotine and reduced tobacco-specific nitrosamines with certified values for composition. |
Menthol levels in cigarettes from eight manufacturers
Ai J , Taylor KM , Lisko JG , Tran H , Watson CH , Holman MR . Tob Control 2017 27 (3) 335-336 Menthol-labelled cigarettes accounted for almost one-third of the US cigarette market in 2012.1 Menthol may be present in cigarettes not labelled to contain menthol, either by intentional addition in small quantities,2 as a contaminant in the manufacturing facilities which were used for menthol cigarettes production,3 or as a naturally occurring constituent in tobacco.4 We previously examined menthol amounts in 46 commercial cigarettes. The amount of menthol measured in the whole cigarettes ranged from 2.9 to 19.6 mg/cigarette for menthol-flavoured cigarettes and from 0.002 to 0.07 mg/cigarette for cigarettes without a detectable menthol flavour.5 In an effort to understand how menthol may be used by various cigarette manufacturers, here we present the repeated and additional measurements of menthol quantities in the cigarette rods, cigarette filters and whole cigarettes of these 46 cigarettes from the following manufacturers: Commonwealth Brands, Liggett Group, Lorillard Tobacco, Philip Morris USA, RJ Reynolds Tobacco, British American Tobacco and Santa Fe Natural Tobacco (SFNTC) and compare them with University of Kentucky reference cigarettes. SFNTC Company is a subsidiary of RJ Reynolds Tobacco Company and the University of Kentucky only makes reference cigarettes which are not for commercial consumption. Instead of examining the menthol levels of different cigarette brands,5 we consider the levels of menthol application among cigarette manufacturers and explore whether there are patterns with different manufacturers for menthol-flavoured cigarettes. We also consider possible sources of menthol in non-menthol-flavoured cigarettes (intentionally added or contamination in the manufacturing facility). Menthol content measured in the whole cigarette for the 46 products of these manufacturers is shown in figure 1. There are three products with measured menthol content >10 mg/cigarette: two are Camel Crush cigarettes and the other is SFNTC Natural American Spirit (NAS) Light Green Menthol. Another tested SFNTC NAS menthol cigarette also has a relatively high level of menthol (7.9 mg/cigarette). All of these products are from RJ Reynolds Tobacco Company and its subsidiary, SFNTC. Except for these four products, the menthol contents in the other 19 menthol cigarette products span a relatively narrow range as can be seen in figure 1. This menthol range (3.3–6.4 mg/cigarette) covers cigarettes across six tobacco manufacturers. RJ Reynolds’ Capri Green has the least menthol content (3.27 mg/cigarette) among the tested menthol cigarettes. However, this lowest tested menthol level is more than three times higher than the menthol perceptive threshold of 1 mg/g of tobacco.6 Other manufacturers such as Philip Morris, Lorillard Tobacco and Liggett Group also have menthol products at this level (<4 mg/cigarette). Considering cigarette design features, for example, tobacco weight, paper permeability and filter ventilation, the menthol content added to different brands of cigarettes should exhibit differences in menthol delivery to the smoker.3 The observed narrow ranges of menthol content suggest that menthol application is relatively consistent for menthol-flavoured cigarettes across US cigarette manufacturers. |
Caffeine concentrations in coffee, tea, chocolate, and energy drink flavored e-liquids
Lisko JG , Lee GE , Kimbrell JB , Rybak ME , Valentin-Blasini L , Watson CH . Nicotine Tob Res 2016 19 (4) 484-492 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 microg/g). Detectable caffeine concentrations ranged from 3.3 microg/g to 703 microg/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 microg/g to 9290 microg/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. |
Characterization of SPECTRUM variable nicotine research cigarettes
Richter P , Steven PR , Bravo R , Lisko JG , Damian M , Gonzalez-Jimenez N , Gray N , Keong LM , Kimbrell JB , Kuklenyik P , Lawler TS , Lee GE , Mendez M , Perez J , Smith S , Tran H , Tyx R , Watson CH . Tob Regul Sci 2016 2 (2) 94-105 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. |
Menthol content in U.S. marketed cigarettes
Ai J , Taylor KM , Lisko JG , Tran H , Watson CH , Holman MR . Nicotine Tob Res 2015 18 (7) 1575-80 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 45 whole 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. |
Nicotine delivery and pharmacologic response from Verve, an oral nicotine delivery product
Koszowski B , Viray LC , Stanfill SB , Lisko JG , Rosenberry ZR , Potts JL , Pickworth WB . Pharmacol Biochem Behav 2015 136 1-6 Verve, an oral nicotine delivery product (ONDP), was introduced by Nu Mark (Altria Client Group, Richmond VA) for smokers to use in places where smoking is prohibited. This study assessed the effect of this ONDP on plasma nicotine levels, heart rate, product satisfaction, and ability to suppress smoking urge and cigarette cravings. Thirteen daily cigarette smokers [8 men and 5 women; average age 33.4years] attended two laboratory sessions, one occurred after overnight tobacco abstinence. Plasma samples were collected before and after ONDP use and measured for nicotine. In non-abstinent smokers, mean plasma nicotine levels increased from 18.3 to 21.0ng/mL. In abstinent smokers, average nicotine levels increased from 3.1 to 4.5ng/mL. After overnight tobacco abstinence, ONDP use significantly (p<0.01) increased heart rate from 69 beats per minute (bpm) to 75bpm; while urge to smoke decreased significantly (p<0.01) from a score of 8.6 to 4.9. Participants indicated moderate product satisfaction that was not changed by tobacco abstinence. Analysis of unused ONDP revealed total nicotine levels of 1.68+/-0.09mg/disc. Spent ONDP discs were also analyzed to determine % nicotine liberated during chewing; results were 80% in the non-abstinent and 82% in the abstinent conditions (ns). Our study results indicate ONDP use can increase plasma nicotine levels and heart rate and reduce cigarette cravings in abstinent smokers. |
Comprehensive chemical characterization of rape tobacco products: nicotine, un-ionized nicotine, tobacco-specific n'-nitrosamines, polycyclic aromatic hydrocarbons, and flavor constituents
Stanfill SB , da Silva AL , Lisko JG , Lawler TS , Kuklenyik P , Tyx RE , Peuchen EH , Richter P , Watson CH . Food Chem Toxicol 2015 82 50-8 Rape, a diverse group of smokeless tobacco products indigenous to South America, is generally used as a nasal snuff and contains substantial amount of plant material with or without tobacco. Previously uncharacterized, rape contains addictive and harmful chemicals that may have public health implications for users. Here we report % moisture, pH and the levels of total nicotine, un-ionized nicotine, flavor-related compounds, tobacco-specific N-nitrosamines (TSNAs) and polycyclic aromatic hydrocarbons (PAHs) for manufactured and hand-made rape. Most rape products were mildly acidic (pH 5.17 - 6.23) with total nicotine ranging from 6.32 to 47.6 milligram per gram of sample (mg/g). Calculated un-ionized nicotine ranged from 0.03 to 18.5 mg/g with the highest values associated with hand-made rapes (pH 9.75 - 10.2), which contain alkaline ashes. In tobacco-containing rapes, minor alkaloid levels and Fourier transform infrared spectra were used to confirm the presence of Nicotiana rustica, a high nicotine tobacco species. There was a wide concentration range of TSNAs and PAHs among the rapes analyzed. Several TSNAs and PAHs identified in the products are known or probable carcinogens according to the International Agency for Research in Cancer. Milligram quantities of some non-tobacco constituents, such as camphor, coumarin, and eugenol, warrant additional evaluation. |
Chemical composition and evaluation of nicotine, tobacco alkaloids, pH, and selected flavors in e-cigarette cartridges and refill solutions
Lisko JG , Tran H , Stanfill SB , Blount BC , Watson CH . Nicotine Tob Res 2015 17 (10) 1270-8 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. |
Quantitation of ten flavor compounds in unburned tobacco products
Lisko JG , Stanfill SB , Watson CH . Anal Methods 2014 6 (13) 4698-4704 Most research on unburned tobacco has focused on the harmful chemicals associated with the tobacco itself. However, certain flavor additives in tobacco products can pose additional health risks. Flavors like camphor, coumarin, pulegone, eugenol, methyl salicylate, menthol and diphenyl ether have exhibited biological activity and/or toxicity in both lab animals and humans. This publication presents a new GC/MS method for the quantitation of ten flavor compounds (eucalyptol, camphor, menthol, pulegone, ethyl salicylate, methyl salicylate, cinnamaldehyde, eugenol, diphenyl ether and coumarin) in a variety of tobacco products, including smokeless products and cigar filler. Excellent linearity (0.997), accuracy (93.9-106.6%) and precision (CV, 0.5-3.0%) were achieved for all flavor analytes measured. A summary of the concentrations of these flavors in selected international smokeless tobacco (SLT) products including zarda, quiwam, gutkha, and khaini varieties from Southeast Asia and snuff, clove cigarette filler and flavored cigar filler from the United States is reported. High concentrations of eugenol (2110 g g-1), coumarin (439 g g-1), camphor (1060 g g-1) and diphenyl ether (4840 g g-1) were found in selected products. Accurate identification and quantitation of potentially hazardous flavor compounds is important because they can exist in relatively high levels in some tobacco products, including international SLT products. We outline a versatile method which can be used to quantitate flavor compounds in multiple types of tobacco products. |
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