Tobacco Aroma Chromatography - Mass Spectrometry Combined With Analysis And Research

The aroma of tobacco is one of the most important factors in evaluation of it quality, so the research of tobacco aroma constituents for improving and monitoring the quality of cigarette is significant. Because conventional flavors are easy to volatile and sublimation, fragrance can not last long, which is great disadvantage for keeping the style and quality of tobacco in its production, processing and storage. Flavor precursors can solve this problem. The development and application of flavor precursors are an important part in the study of tobacco flavors. Therefore, it is necessary to research these substances, learn more about these substances, and make it full use in tobacco. Following four investigations of work were done.1. Extraction and GC-MS analysis of essential oil. Volatile oil of spice tobacco and flue-cured tobacco are obtained by simultaneous distillation-solvent extraction. Following, the essential oil is analyzed by gas chromatography-mass spectrometry.45 and 42 components in two kinds of essential oil were identified separately, constituting approximately 89.4% and 93.7% of the oil. The main components of volatile oil are hydrocarbons, acids, aldehydes, ketones, alcohols and alkenes. Totally,13 kinds of compounds of two essential oils are identical.2. Extraction and Purification of the glycosides and sucrose esters. Based on the amount of extracted glycosides and sucrose esters, we studied the extraction solvent, time, solid to liquid ratio and extraction times, at last obtained the best extraction conditions. After extraction, glycosides were efficiently separated by chromatography on AmberliteXAD-2 column, and sucrose esters were well separated by SephadexLH-20 resin column.3. Liquid chromatography-mass spectrometry analysis of glycosides and sucrose esters. With high performance liquid chromatography-mass spectrometry(LC-MS), five glycosides were well separated on C18 column with mixtures of methanol and water as mobile phase, and the molecular weight of five glycosides were obtain simultaneously. The structures of the glycosides were further studied by ESI-MSn; the sucrose esters were studied by LC-MS, accurate molecular weights were determined through ESI-MS on-line detection, and fragment of sucrose esters were obtained by off-line analysis.4. Pyrolysis-gas chromatography-mass spectrometry analysis of glycosides and sucrose esters. Simulated smoking process, glycosides and sucrose esters were studied on their thermolysis with a pyrolyser connected directly to a gas chromatograph in specific temperature, and analyzed the flavor and fragrance that the glycosides and sucrose esters produced after the thermolysis.