Principal component analysis monoterpene hydrocarbons from

The modified Ir data for monoterpene hydrocarbons from the three species of citrus oils were subjected to a multivariate analysis. According to principal component (PC) analysis, the citrus essential oils examined were clearly discriminated, with 93.3% of the accumulation contribution ratio of both PCI and PC2 (Fig. 4A). As shown in Fig. 4B, p-pinene (PCI, 0.530 PC2, -0.80), a-terpinene (0.685 0.062) and P-phellandrene (0.324 0.810) were large for the absolute value of the eigenvector of monoterpene system hydrocarbons, followed by terpinolene (0.367 -0.010). These compounds greatly contributed to the modified Ir discrimination of the citrus essential oils. 

Figure 4. Principal Component Analysis of the modified Ir values of the monoterpene hydrocarbons from citrus oils.

The GC-MS and HPLC analyses of oils from Salvia sclarea provided a comparative analysis profile of different plant materials. Sesquiterpene hydrocarbons (e.g., germacrene D and (3-caryophyllene), monoterpene alcohols (e.g., ot-terpineol), diterpenoids (mainly sclareol), monoterpene hydrocarbons (e.g., myrcene, limonene, and the two ocimene isomers), and the principal components (linalyl acetate and linalool) were analyzed. 

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