Study on Spatial Distribution of Chemical Components in Flue Cured Tobacco Leaves by Imprinting Analytical Electrospray Photoionization Mass Spectrometry
The imprint desorption electrospray photoionization mass spectrometry was employed to locally image the spatial distribution of chemical components in dried tobacco leaves after initial curing. The relative content distribution of different chemical components was obtained in tobacco leaves. The application of imprinting method could transfer tobacco internal compounds to the surface of porous polytetrafluoroethylene plate,which realized the detection and visual analysis of tobacco internal substances. Besides,the imprint desorption electrospray ionization/post-photoionization (Imprint DESI/PI) mass spectrometry imaging technique had the advantages of non-polarity discrimination,soft ionization and high ionization efficiency for plant samples,and could simultaneously detect and image rich compounds in tobacco samples. A total of 40 kinds of chemical components including alkaloids,amino acids,sugars,acids,ketones and phenols were identified based on high resolution mass spectrometry. The results showed that the representative chemical components of tobacco,such as alkaloids,amino acids and sugars,were mainly distributed near the leaf tip from the vertical analysis and at the left and right leaf edges from the horizontal analysis. Amadori compound (1-Deoxy-1-L-proline-d-fructose) was detected,and the content of Amadori was found to be consistent with that of free amino acid (proline). In addition,the technique was further used to study the climate spot disease area of tobacco,and it was found that the compounds had specific distribution in the climate spot area,which further proved the superiority of this method in studying the growth stress of tobacco leaves.