Figure 6.

Peppermint essential oil chromatograms, showing: (a) the ¹D GC-FID result indicating the regions 1–5 to be heart-cut; (b) the ²D GC-FID results of the analysis of all the five heart-cuts with cryofocussing; (c) the expanded separation window, comparing the separation of all five selected regions, with retention times given from the introduction of each region to the ²D column; and (d) the expanded result of heart-cut 4, showing a total retention time of about 24 s. Source: adapted with permission from Dunn et al. [116].