Chemometric analysis of gas chromatographic data of oils from Eucalyptus species

Gas chromatograms (GCs) of oil extracted from Eucalyptus species have been compared using principal components analysis (PCA), linear discriminant analysis (LDA), and the Tanimoto distance in which the number of similar peaks between two species are determined. stems were studied, a number of examples of E. camaldulensis Dehnh. (River Red Gum) and clones of that species, and samples from two trees E. woodwardii Maiden and E. torquata Luehm. and a number of their hybrids (E. torwoodii). A revealed natural groupings of E. camaldulensis clones and showed, via loading plots, that eight intensities of the 180 times studied were sufficient to explain most of the variance and characterise each tree. The chemical species were identified by GC-mass spectrometry as a-pinene, 1,8-cineole, p-cymene, terpinen-4-ol/aromadendrene, cryptone, borneol, spathulenol, and torquatone. ybrid (E. torwood) of the trees E. woodwardii and E. torquata has a distribution of oils that lies between those of the parents. LDA was able to define two distinct groups and performed better than the Tanimoto distance in classifying the trees.