Study On Analysis And Fingerprint Of Tobacco Flavor By Gas Chromatography-Mass Spectrometry

The fingerprint has been increasingly utilized as practical method for the identification and quality evaluation of tobacco flavor.It can be comprehensive and integrated to reflect their inner components.So far there's a great variety of tobacco flavors and their components are different and complicated.So it's necessary to choose the suitable pretreatment method to extract the components of tobacco flavor.In this thesis,the pretreatment and detection methods,research status of tobacco flavor,application of the GC fingerprints in tobacco flavor were introduced.And then three different pretreatment methods of ultrasound-assisted liquid-liquid extraction(ULLE),head space-solid phase microextraction(HS-SPME)and head space-liquid phase microextraction(HS-LPME)were investigated on the analysis of 5 kinds of the tobacco flavors and the GC fingerprints with pattern recognition were developed.Ultrasound-assisted liquid-liquid extraction(ULLE)was used to extract the components of tobacco flavor 1187#,and the components were analysed by GC/MS.The optimal extracting conditions are established as follows:extracting solvent is solvent pairs with CH2Cl2 and CH3CH2OH(9:1(v/v));saturated NaCl solution is used as water phase and ultrasound extracting time is 10 min.The fingerprints of tobacco flavor named 1187#were successfully established.2 samples mixed with other kind of flavor components were obviously distinguished from the 11 batches of 1187#samples by principal component analysis(PCA).Thus,this method is suitable for the quality control of this tobacco flavor.Head space-solid phase microextraction(HS-SPME)and ULLE were used to extract the components of tobacco flavors 1127#and 1115#,and the components were analyzed by GC/MS.The results indicated that HS-SPME is more suitable for the extraction of components of these two flavors.Effects of different types of SPME fiber,extracting time and temperatures on the results were studied,and the optimal extracting conditions are obtained.The components of nine batches of tobacco flavor 1115#samples were analyzed and the fingerprint of the flavor was established.Furthermore,The fingerprint of different batches of the flavor were compared by using hierarchical cluster analysis.The feasibility of developed SPME method in quality control of tobacco flavor was examined by spiked samples.The pretreatment method of head space-liquid phase microextraction(HS-LPME)was developed on the analysis of tobacco flavors 1133#and 1148#and the components of 2 flavors were analysed by GC/MS.The results were compared with the methods of HS-SPME and ULLE and it shows that HS-LPME had better performance for the extraction of low volatile components of tobacco flavor.Effects of different types of extraction solvent,extraction time and temperatures of HS-LPME on the results were studied,and the optimal extracting conditions are selected as following:after balanced at 70°C for 1hour with the stirring rate at 300r/min,4.0?L of dodecane as extraction phase for the time of 10min.The pattern recognition of flavor samples of 1148#was carried out with principal component analysis(PCA).The research results shows that the established method can distinguish the spiked sample successfully,and it is an effective method for tobacco flavor 1148#quality control.