Method Of Determination Of Important Compounds In Tobacco

It is important that analysis of the components in tobacco leaf,especially the flavor and aroma compounds,such as soluble carbohydrates,carotenoids,cembranoid diterpenes and so on.As a tool,Analytical chemistry plays an important role in the study of tobacco leaf and smoke.In this thesis,three kind of important compounds in tobacco leaf,include soluble carbohydrates,carotenoids,cembranoid diterpenes,were studied.1.A high performance liquid chromatographic method with evaporative light scattering detector(ELSD) was established for the determination of soluble carbohydrates in tobacco leaf,such as rhamnose,xylose,arobinose,fructose,mnnose,glucose,sucrose and maltose. The soluble carbohydrates in tobacco leaf were separated by solide phase extraction with Sep-pak-C₁₈ cartridge.These carbohydrates were separated on carbohydrate column(waters carbohydrate,250 mm×4.6 mm i.d.,4μm) using an V(acetonitrile):V(water)=70:30 at a flow-rate of 1.0mL/min.Regrssion equations revealed linear relationship(correlation coefficient=0.9931-0.9992) between the mass of carbohydrates injected and the carbohydrates peak areas deteced by ELSD.The recoveries were high and reproducible, ranging from 84.0%to 120%.This method had been successfully applied to the determination of soluble carbohydrates in tobacco leaf with good result.2.A new method,using sudan I as internal standard to determine the content of carotenoids in tobacco leaf,includeβ-carotene and lutein,was developed.According to UV-vis absorption spectra,sudan I,β-carotene and lutein all had absorption peaks at 450nm.They could be separated absolutly by high performance liquid chromatography with retention time of 5.85min,8.45min,17.28min,respectively.The related equations between sudan I andβ-carotene or lutein content were obtained and verified by determining the content ofβ-carotene and lutein in tobacco leaf.The relative error was 0.4%,for determiningβ-carotene content and 1.8%for lutein.Intra-day variability forβ-carotene was 5.8%and for lutein was 7.1%.The mean recovery ofβ-carotene or lutein was 116.2%and 96.8%.3.α-2,7,11-cembratriene-4,6-diols(α-CBD),β-2,7,11-cembratriene-4,6-diols(β-CBD) are precursors of important tobacco smoke flavor and aroma compounds.A HPLC-UV method,using 20(R)-ginsenoside Rh2 as internal standard to determine the content of cembranoid diterpenes in tobacco leaf,was developed. Meanwhile,a simple and efficient pre-treatment method for extracting cembranoid diterpenes in tobacco leaf was developed.The relative error was 0.6%,for determiningα-CBD content and 2.2%for β-CBD.Intra-day variability forα-CBD was 9.8%and forβ-CBD was 7.9%.The result revealed the content ofα-CBD in tobacco leaf was 6.20mg/g,andβ-CBD was 2.62 mg/g,the ratio was 2.36, according with the result which was in reported previous literatures.