- Journal Details
- Format
- Journal
- eISSN
- 2719-9509
- First Published
- 01 Jan 1992
- Publication timeframe
- 4 times per year
- Languages
- English
Search
- Open Access
Inter-Laboratory Reproducibility and Interchangeability of 3R4F and 1R6F Reference Cigarettes in Mainstream Smoke Chemical Analysis and In Vitro Toxicity Assays
Page range: 119 - 135
Abstract
A new reference cigarette, 1R6F, produced by the Kentucky Tobacco Research and Development Center, has been manufactured as a substitute for the 3R4F reference cigarette because of a depletion of 3R4F stock. The purpose of the current study was to investigate the interchangeability of 1R6F and 3R4F by comparing the chemical and biological characteristics of the mainstream smoke and to assess the inter-laboratory reproducibility by comparing the results obtained in the current study with a previous report. We analyzed 45 priority chemicals required by Health Canada for regulatory reporting and assessed the toxicological effects of cigarette smoke using
Keywords
- Mainstream cigarette smoke
- inter-laboratory reproducibility
- chemical analysis
- toxicity
- Open Access
Relationship Between Nicotine Dependence Scores and Nicotine, Cotinine, 3′-Hydroxycotinine and Nicotine Metabolite Ratio in Chinese Male Smokers
Page range: 136 - 144
Abstract
Smoking is mainly sustained by nicotine dependence (ND), which varies across ethnic groups principally due to genetic as well as environmental factors. The Fagerström Test for Nicotine Dependence (FTND) and biomarkers of tobacco exposure are two important approaches to assess ND. However, the relationship between ND and FTND of Chinese smokers has not been studied. The aim of this study was to assess the relationship between FTND scores and nicotine, cotinine, 3′-hydroxycotinine (3HC) and nicotine metabolite ratio (NMR, the concentration ratio of 3HC to cotinine) in Chinese smokers. FTND was carried out and general characteristics were collected using a self-administered smoking questionnaire with 289 smokers. Nicotine, cotinine and 3HC in urine were simultaneously determined by liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS). The concentrations of nicotine, cotinine and 3HC in the urine of smokers with a high FTND score were higher than in the urine of those with a low FTND score. There were significant correlations between urinary biomarker and FTND scores. Except for FTND item 2 (difficulty to refrain), the other items showed significant associations with the urinary biomarkers. No relationship was found between the nicotine metabolite ratio (NMR, 3′-hydroxycotinine/cotinine) and FTND scores or general characteristics of the participants. In conclusion, biomarkers of tobacco exposure levels are significantly associated with FTND scores. However, FTND Item 2 and NMR were not found to be associated with nicotine dependence in Chinese smokers.
Keywords
- Nicotine
- cotinine
- 3′-hydroxycotinine
- nicotine-metabolite ratio
- nicotine dependence
- Open Access
Simulation of Heat and Mass Transfer of Cut Tobacco in a Batch Rotary Dryer by Multi-Objective Optimization
Page range: 145 - 155
Abstract
To simulate the drying process of cut tobacco in a batch rotary dryer, six different models of equilibrium moisture content were selected to calculate the driving force of mass transfer, and a mathematical model of heat and mass transfer was numerically solved. The multi-objective nonlinear problem of heat and mass transfer coefficients was optimized by employing a weight factor. The simulation results showed that the weight factor r was an important parameter for fitting results of moisture content and temperature. The model evaluation indices almost reached their minimal values with r at 0.1. For all the six equilibrium/classic models the fit was better for moisture content than for temperature. One model (M-H
Keywords
- Cut tobacco
- drying
- heat and mass transfer
- equilibrium moisture content
- multi-objective optimization
- Open Access
Numerical Simulation of the Burning Process in a King-Size Cigarette Based on Experimentally Derived Reaction Kinetics
Page range: 156 - 179
Abstract
A comprehensive two-dimensional (2D) mathematical model has been proposed to simulate the burning process of a king-size cigarette. The characteristics of this model are including: 1) the use of kinetic models for the evaporation of water, the pyrolysis of tobacco and the oxidation of char, 2) the application of mathematical relationships between the release amounts of certain products (i.e., “tar” and CO) and different reaction variables (i.e., temperatures and oxygen concentrations), 3) the introduction of mass, heat and momentum transports, 4) the consideration of filtration effects of the cigarette filter on “tar”. These characteristics were expressed in a set of coupled equations that can be solved numerically by FLUENT. The information about the char density field, temperature field, flow velocity field, “tar” and CO density fields and the filtration efficiency could be obtained from the model. This model was validated by comparing the predictions with experimental data on puff number, the temperatures at specific locations, the filtration efficiency and the yields of “tar” and CO under different puff intensities. The calculated results show a good agreement with the experimental data. The predicted puff number was 7.3, and the experimental puff number was 6.8. The standard root mean square error (NRMSE) between the experimental and the predicted temperatures at specific locations is < 18%. The predicted filtration efficiency for “tar” was 46.1%, and the experimentally determined filtration efficiency for nicotine was 44.5%. The maximum relative deviations of the yields of “tar” and CO under different puff intensities were 8.9% and 10.6%, respectively.
Keywords
- Numerical simulation
- cigarette burning process
- pyrolysis
- combustion
- “tar” and CO release
- filtration efficiency