A method was developed for the qualitative and quantitative determination of glucose tetra-esters( GTEs) in tobaccos by gas chromatography-mass spectrometry( GC-MS) after ultrasonic extraction. The ultrasonic extraction parameters were optimized by response surface methodology( RSM). The optimal conditions were to use methanol as the extraction solvent within 16 min at 32 ℃ and the solid liquid ratio was 1: 28. The GTEs extracted from tobaccos were cleaned up by a silica column and derived with N,O-bis( trimethylsilyl) trifluoroacetamide( BSTFA)-trimethylchlorosilane( TMCS). The GTE derivatives were separated by gas chromatography using a HP- 5MS capillary column and detected by mass spectrometry. Full scan mode and SIM mode were used for the qualitative and quantitative analysis,respectively. Four kinds of GTEs were identified from tobaccos,and they were 6-O-acetyl- 2,3,4-tri-O-( 3-methylbutyryl)-glucopyranose,6-O-acetyl- 2,3,4-tri-O-valeryl-glucopyranose,6-O-acetyl- 2,3,4-tri-O-isoamyl-glucopyranose and 6-O-acetyl- 2,3,4-tri-O-( 3-methylvaleryl)-glucopyranose. The average recoveries of the four GTEs in the range from 86. 2% to 97. 4%( n = 5),the relative standard deviations were between 1. 3% and 4. 0%,and the detection limits were in the range of 1. 72 ~ 2. 93 μg / L. The method for the detection of four GTEs in 11 tobacco samples was sensitive and highly reproducible with satisfactory recoveries.

The ultrasonic-assisted extraction technology of sucrose esters( SE) from tobacco was studied.The qualitative and quantitative analysis was performed by gas chromatography-mass spectrometry( GCMS) method,and the effect of various factors including extraction solvent,temperature,time and solid liquid ratio on the total extract yield of SE was investigated by response surface methodology( RSM). The results showed that the optimal extraction conditions were as follows: the extraction solvent acetonitrile,the solid liquid ratio 1∶ 29,the temperature 43 ℃ and the extraction time 16 min. Under the optimized conditions,the total extract yield of SE was 5. 039( actual) or 5. 067( theoretical),the average recovery was99. 87%,7. 74 % more than that obtained under the optimized conditions of single facter tests. The determination results of 10 kinds of tobacco leaf showed that the kinds and content of SE in tobacco leaves were different with different origin,variety and level.

The pretreatment technique of microwave-assisted extraction coupled to headspace solid-phase microextraction(MAE-HS-SPME) was investigated on the extraction of aroma components from Zanthoxylum bungeanum Maxin.The extracted volatiles were analyzed by gas chromatography-mass spectrometry(GC-MS) method,and the determination results were compared with that of simultaneous distillation and extraction(SDE) and HS-SPME methods.The results showed that the optimal extraction conditions of MAE-HS-SPME were extracting 5 min at 120 W microwave power from 10 g sample in 100 mL deionized water using a 100 μm polyacrylate(PA) fiber,and then desorbing for 20 s at 250 ℃.The GC-MS analysis results showed that 59 components were identified and accounted for 96.65% of the total peak areas.The main volatiles were the same as that separated from HS-SPME fiber and SDE method.The main volatiles were linalool,linalool acetate,etc.The total num-ber of the components extracted by MAE-HS-SPME was more than that extracted by HS-SPME and SDE.The results indicated that MAE-HS-SPME is a high performance pretreatment method.

A method for the analysis of sucrose tetra-ester(STE)in ultrasonic–assisted extraction products from tobaccos by gas chromatography-mass spectrometry(GC-MS)was developed.The STE were extracted under the optimal extraction conditions which optimized by the response surface methodology,the STE derived with N,O-bis(trimethylsilyl)trifluoroacetamide and analyzed by GC-MS method.The contents of STE in tobaccos were determined by internal standard curve method and 19 kinds of tobacco were analyzed.The results showed that the average added standard recovery of the method developed by this paper was in the range of 98.53%～101.49%,the relative standard deviations(RSD)were less than 2.9%,the correlation coefficients were more than 0.999 and the detection limits were in the range of 0.14～0.17μg/mL.5 kinds of STE(STEⅠ～SE Ⅵ)were identified from oriental tobacco,3 kinds of STE(STEⅠ,SE II and SE IV)were identified from flue-cured and 2 kinds of STE(STE I and SE II)were identified from cigarette.The total content of STE in oriental tobacco was higher than that in flue-cured and cigarette,and flue-cured has the least content of STE.

A method for the analysis of menthol in mentholated cigarettes and mainstream smoke by gas chromatography-mass spectrometry select ion monitoring(GC-MS,SIM)method was developed and the transfer rate in smoke was determined.Menthol in mentholated cigarettes and total particulate matter of mainstream smoke was extracted by ethanol and determined by internal standard curve method using n-heptadecane as internal standard.The results showed that the added standard recoveries of menthol were in the range from 99.34% to 100.04% in different samples,and the relative standard deviations(RSD)was below 2.6%;the correlation coefficients was more than 0.999 and the detection limits was 0.12μg/mL.The transfer rates of menthol in mainstream smoke varied with tar content in different mentholated cigarettes.The transfer rate increased with the tar content,the highest was up to 47.79%.