Figure 4.

Topographic plots of the compounds isolated from AEOs from different regions using gas chromatography–ion mobility spectrometry (GC-IMS): A (Wenshan), B (Nujiang), C (Tengchong). (A) depicts the total volatile organic compounds (VOCs), and each colored point represents a compound. Red represents high concentration, and dark blue represents almost not present. Increasing color darkness from dark blue to red depicts increasing concentration. In (B), for VOCs of analytes with the same concentration compared to the reference (A1), the color would be white. Red and blue indicated that the concentration of VOC is more and less than the reference, respectively.