The Research On Analytical Technology Of Some Important Chemical Components And Composition Relevancy In Tobacco

Today, anti-smoking campaign is springing up around the world. Therefore, how to improve the quality of tobacco products and reduce the contents of harmful substances in tobacco is an important task faced by scientists in tobacco industry. To achieve this, it is vital to study tobacco chemical and instrumental analytical techniques, develop corresponding experimental technology, and set up a series of new analytical method for measurement of those components associated with tobacco quality and its sucking security. With the help of these analytical methods, the relevancy between the contents of harmful components and aroma substances in tobacco could be studied in order to take corresponding controlled action. This will give a fundamental support for us to improve cigarette quality of Chinese style with the character of "high flavor and low harmfulness" . In the present thesis, the following research works were carried out on the basis of extensive literature investigation.1. A method for the determination of tobacco-specific nitrosamines(TSNA) in tobacco smoke using capillary gas chromatography—NPD measurement was developed. A series of experimental conditions, such as smoke substance collection, extraction time, and chromatography substance conditions, were optimised. The new method avoided the phenomenon of emulsification during sample pretreatment, which was often found in past literatures for TSNA determination. The new method has the advantage of high sensitivity, good repeatability and dispensing expensive special equipment. The method will find application in general tobacco laboratory and be suitable for the supervision of tobacco products in tobacco enterprises.2. A spectrophotometric method for the determination of N-nitrosamines in tobacco was developed. The internal relation between the content of N-nitrosamines in tobacco and of corresponding tobacco extractives was investigated, It was shown that aroma substances in tobacco leaf was associated with its N-nitrosamines content in some degree. Our experimental results also indicated that the more the content of aroma substances in tobacco leaf, the less that of nitrosamines. In particular, the content of aroma substances in YunNan tobacco leaf was more ample than that in HuNan tobacco leaf at the same grade, and the content of nitrosamines in YunNan tobacco leaf less than that in HuNan tobacco leaf at the same grade.3. A new analytical method for the determination of potassium in tobacco wasestablished by the combination of suspention sampling and flame atomic absorption spectrophotometry with agar to be suspending agent for the first time. Standard curve and standard addition methods were applied for the quantitative analysis of potassium in tobacco. The main advantage of this method is that the tobacco powder can be directly injected as suspended sample, and has no need for cineration in advance. In addition, the new method is high repeatable and accurate, and is suitable for the measurement of large quantities of tobacco sample.4. A new method for the determination of chlorogenic acid in tobacco by molecular imprinted polymer modified piezoelectric bio-mimetic sensor was first described. The method is simple in operation, easy to carry out online measurement and its features includes high reproducibility and sensitivity. The method recovery is 96.7-105.0%, RSD 3.7%, and linear range 5.0× 10-8~1.0× 10-4mol/L. Beside, the sensor used in this method is cheap, and with the characteristic of high thermal stability and mechanical stability.