| Snus and gum-based chewing tobacco which are more popular in China compared with other forms smokeless tobacco were chosen as the research objects. According to the characteristics of snus and gum-based chewing tobacco, different analysis methods for determination the content of nicotine were built. In the meantime, the release model of nicotine in vitro was set up, and an on-line detecting system was included this model, which was based on the ultraviolet-visible spectrophotometer and flowing cell. This paper is composed of three sections as follows:1. In order to determinate nicotine content in artificial saliva release from snus by UV-VIS spectroscopy rapidly, a method was build by using methyl orange as complexing agent while dichloromethane as extracting agent under the condition of pH=4.6. As the results show that this method is accurate, effective and convenient, in which the linearly related coverage is1-70mg/L, the related coefficient is0.9995, the recovery rate is between97.6%and102.8%, and it’s RSD is less than3%. This method and the release model of nicotine in vitro were used to study the release rates of nicotine of multiple snus, both domestic and international. At the same time, the influence of pH, moisture content of products, size of tobacco powder and the tissue material of the pouch were studied. The results showed that the release rate of nicotine decreases with increasing of pH, size and density of bag about snus, and increases with decreasing of moisture content.2. Based on gas chromatography-mass spectrometry instrument, a method was build for determining the content of nicotine in gum-based chewing tobacco. Under optimum conditions, this method can be applied to different types of gum-based chewing tobacco with higher veracity and excellent accuracy, and the recovery rate is between92.9%and105.2%, and RSD is less than2.0%. By using the release model of nicotine in vitro with the method mentioned above, the release behaviors of five flavors of gum-based chewing tobacco were studied. The results showed that, there were significant differences in the release behavior of different flavors.3. In order to study the release behavior of nicotine from snus in vitro and determinate nicotine content in artificial saliva release instantaneously, an on-line detecting device was set up:based on the system of flowing cell and ultraviolet spectrophotometer, meanwhile some conditions for this experiment was optimized. This study result shows that the golal of determinating nicotine content on-line while releasing might be possible to achieve, and the device is feasible with good prospect of application. |
