SEARCH Articles Figures Tables GC X GC analysis of vetiver essential oil column 1, BPX5 column 2, BPX50 . The lower trace presents the pulsed peaks obtained from the modulation process, and shows such peaks in a manner that represents the normal cliromatograpliic result presentation. Tliis nace is many times more sensitive than a normal GC trace. In the upper plot, the 2D separation space shows that the BPX50 column is not very effective in separating components of the oils based on polarity, since all the components are bunched up along the same region of 2D time. [Publishers Imprint]