Simultaneous Determination Of Polyphenols And Nicotine In Tobacco By HPLC And Their Distribution In Different Tobacco Growth Periods

Tobacco analysis is the base of tobacco chemistry. For powerful separating ability and good selectivity, high performance liquid chromatography (HPLC) has unique merit in analysis complex sample such as tobacco. Developing techniques for determination components in tobacco by using HPLC has important application value. This thesis has established a new HPLC method for simultaneous determination nicotine and polyphenols in tobacco, and then applying to study the effect of sunlight-conversion film (SCF) and sunlight-conversion and reflection film (SCRF) on polyphenols and nicotine in tobacco. Primary studies are included as following:1. Anew HPLC method was developed for simultaneous analysis nicotine and four polyphenols in tobacco. Optimal conditions for separation of nicotine and four polyphols, such as mobile phase, elute mode, wavelength, were investigated. This method appears simple, accurate and precise. Four extraction methods applied to extract nicotine and polyphols in dry tobacco leaf were compared and found that the ultrasonic extraction was efficient than other methods. Furthermore, the conditions of ultrasonic extraction were optimized.2. The effect of SCF on polyphenols and nicotine in tobacco was studied by using the fore mentioned HPLC method. It was found that nicotine content kept immovable nearly, rutin content increased appreciably but chlorogenic acid increased in the first place and then decreased. It was also found that SCF has little effect commonly on the contents of chlorogenic acid, nicotine and rutin in tobacco leaf during 40days when tobacco seedlings were transplanted to farmland except the content of chlorogenic acid increased in SCF1# tobacco leaf, while nicotine and polyphenols contents all increased in tobacco aging period. By a series of researches, rules were found as following: contents of nicotine and rutin increase respectively as tobacco plant grow up but decrease gradually as leaf locations descend. As for their content's increasing extent in tobacco leaf, rutin is not as good as nicotine. Effect of SCF on tobacco plant growth was showed as follows: SCF can improve ground temperature under the film and is propitious to increase root elongate, stem thick, leaf area augment and biologic mass.3. Underside conclusions were obtained by determination polyphenols and nicotine in aging tobacco leaf underside part of tobacco plant on the effect of SCRF: Contents of nicotine, chlorogenic acid and rutin in tobacco leaf are all relatively low and they increase gradually from base to top of leaf in tobacco aging period commonly. SCRF mostly induces contents of polyphenols decrease in the top of tobacco leaf, while the content of rutin in the base of 6# tobacco leaf effect increases on effect of sunlight conversion. Contents of nicotine and polyphenols, in roasted tobacco leaf underside part of tobacco plant on the effect of SCRF, are lower than CK. We also found some growth and distribution rules on the effect of SCRF as follows: the content of nicotine increases gradually in tobacco leaf from middle and top of tobacco plant as plant grows up, and decrease gradually as leaf location falling from the third or the first leaf. Nicotine content of 1# is the highest in every leaf location. In the same appearance mature tobacco leaf, nicotine content of 6# is highest and the others are almost same, the order of chlorogenic acid content is...