.uplc-ms/ms Analysis Of Several Classes Of Flavor Precursors In Tobacco

The chemical compositions of tobacco leaf have direct influences on tobacco products quality. At present, the quality of domestic tobacco in comparison with foreign high-quality leaf has a big disparity, there is mainly a big difference in the tobacco leaf aroma and the fragrance quantity, it showed that the fragrance quantity is insufficient and the smoke is not gentle sufficingly. TheAroma Precursors is stability in the process of tobacco production and storage to avoid the loss of aroma, and can release uniform fragrance in the suction process. Therefore, it is the investigative emphasis in the tobacco aroma and typical local dish. In this paper, ultra-high performance liquid chromatography-electrospray ionization mass spectrometry (UPLC/ESI-MS/MS) on several types of tobacco flavor precursors were studied, summarized as follows:(1) The experiment using ultra performance liquid chromatography-tandem mass spectrometry interfaced with electro-spray ionization (UPLC/ESI-MS/MS), five kinds of aromatic acids and phenolic acids(benzoic acid, phthalic acid,4-coumaric acid, caffeic acid and ferulic acid) in tobacco leaf are rapid determined, The results indicated that:①the content of benzoic acid, phthalic acid,4-coumaric acid and ferulic acid were lower in flue-cured tobacco;②the content of caffeic acid in flue-cured tobacco is much higher than other aromatic acids and phenolic acids, and its content in the domestic is also more than the foreign flue-cured tobacco;③the phenolic acids content of flue-cured tobacco produced in Yunnan Province is higher than other regions.(2) Five kinds of glycosides in tobacco were rapid determined:③use GC-MS to analyse aglycone structure, five kinds of glycosides are identified;②summarize the cracking law of glycosides in the ESI(-) ion source mode;(3) 11 Aroma Precursorssubstances were rapidly screened out and identified:①using the neutral loss scanning function,11Aroma Precursorssubstances were screened out and its structures were identified;②summarize its cracking law in the ESI(-) ion source mode.(4) Five kinds of flavonoids were rapidly screened out and identified:①using the precursor ion scan,5 kinds of rutinose flavanone material were screened out and its structures were identified;②summarize its cracking law in the ESI(-) ion source mode.The cracking law of several types of Aroma Precursorssubstances:①the Aroma Precursors of organic acids will break first to obtain its characteristic acid, for example cumaric acid derivative will break and produce fragment m/z 162.8 of cumaric acid, and then produces the fragment ions m/z 118.9 by loss of -COOH;②monosaccharide will produce aglycone fragments m/z 163 and the aglycone [M-162]-by breaking from aglycone bond connection area, and disaccharide will produce disaccharide aglycone fragments m/z 296, aglycone fragments m/z 163 and [M-295]-;③in the ESI positive and negative ions mode, flavonoids will produce glucoside m/z 309 and fragment ions m/z 331 which are produced by glucoside sugar combined with the Na ions, aglycone ions and some ions that Na ions combining with aglycone ions.As most of the flavor precursors which are plant metabolites, are most difficult to obtain standard samples, at present the research about them are some kinds of organic acids and flavonoids which had obtained standard samples. This article through the UPLC-MS/MS neutral loss scanning and pre-ion scan function,20 kinds of Aroma Precursors are screened out. Some kinds of Aroma Precursors are analyzed in the electro-spray ionization(ESI) ion source mode with MS2 mass spectrum scan, and the cracking law is summarized. The second-level debris-MS spectrum library of some parts of the Aroma Precursors had been established, and the Aroma Precursors content in the upper, middle, lower part of tobacco leaf were compared using the semi-quantitative method. These efforts are helpful in understanding the differences of Aroma Precursors in the various tobacco leaves, and also have a basis on the analysis of Aroma Precursors using liquid chromatography-mass spectrometry in the future.