Determination Of Organic Acids And Polyphenols In Tobacco By HPLC And Research On Sunlight-Conversion Film For Tobacco In Field Experiments

Tobacco chemical analysis plays a very important role in the healthy development of tobacco industry. High performance liquid chromatography (HPLC) known as a kind of separating and analysis technology has a high practice value to analysis of chemical composition in tobacco. In this thesis, a method for simultaneous and rapid determination of 6 organic acids in tobacco leaf by high performance liquid chromatography was developed, and established a new HPLC method for the rapid simultaneous determination of organic acids and polyphenols in tobacco leaf. Then applying it to study the effect of sunlight-conversion film (SCF) and sunlight-conversion and reflection film (SCRF) on growth of tobacco and compounds. The main results are summarized as follows:1. A method for simultaneous and rapid determination of 6 organic acids in tobacco leaf by reverse-phase HPLC was developed, and 6 organic acids were identified and quantified in less than 7 min. Optimal conditions for separation of 6 organic acids, such as wavelength, mobile phase, elute mode were investigated. The method appears the higher sensitivity, precision and better repeatability. At the same time, preparation of the sample was optimized.2. A reversed-phase (HPLC) method was developed for the rapid simultaneous determination of organic acids and polyphenols in tobacco leaf, and they were identified and quantified in less than 20 min. Optimal conditions for separation of the main 4 organic acids and 4 polyphenols, such as wavelength, mobile phase, elute mode were investigated. Furthermore, the conditions of ultrasonic extraction were optimized.Followed by this method to analysis the main 4 organic acids and 4 polyphenols in tobacco leaf.3. The effect of SCF on the main 2 organic acids and 2 polyphenols in tobacco leaf was studied by using the fore mentioned HPLC method. The results indicated that in the growth prophase of tobacco, SCF had more effect on the accumulation of malic acid than CK, but for citric acid, it was contrary. Chlorogenic acid and rutin contents commonly decreased for SCF but increased for CK. In tobacco aging period, SCF had more effect on the accumulation of Chlorogenic acid, rutin in tobacco leaf and citric acid in above leaf than CK, but for malic acid and citric acid in below leaf, it was contrary.At the same time, the effect of SCF on tobacco growth was showed as follows: SCF was more propitious to grow for root, stem and leaf. Comparing to CK, it improved higher ground temperature. Furthermore, it increased the net photosynthesis velocity and improved the contents of chlorophyll a, chlorophyll b and total chlorophyll.4. The effect of SCRF on the main 2 organic acids and 2 polyphenols in tobacco leaf was studied by using the fore mentioned HPLC method. Through a series of researches, it was found as follows: In tobacco aging period, SCRF was commonly propitious to accumulate malic acid, citric acid, chlorogenic acid and rutin in below leaf, but it was more effect for malic acid and citric acid. In addition, we studied the effect of SCRF on thickness of foot leaf. It was found that the thickness of flue-cure tobacco leaf (underside three leaf location) of SCRF was thicker than CK, and then the foot leaf was more sufficient to be utilized.