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dispersive interactions with the derivatized cyclodextrin. Courtesy of Supelco The columns were 30 m long, 0.25 mm I.D., carrying a film of stationary phase 0.25 mm thick of b-DEX™. The column was programmed from 40˚C to 220˚C at 4˚C/min. The helium flow velocity was 35 cm/s. Figure 48 Chromatogram of the Essential Oil From White Pine Leaves It should be noted that whereas the (–)-a-pinene is the first eluted enantiomer of a-pinene it is the (+)-camphene that is the first eluted of the camphene enantiomers. This tends to indicate that there is no rational procedure for predicting the order of elution of an enantiomeric pair

common use was disclosed.   Even the early examples given by James and Martin (2) in one of their first public lectures on the subject, included dramatic separations of multi-component mixtures that fired the imagination of chemists world-wide. For the first time the complex nature of these important materials could be displayed both quantitatively and qualitatively. An example of the separation of an essential oil using modern GC equipment is shown in figure 1 .     1. a-Pinene 7. gÐTerpinene 13. Geraniol 2. Camphene 8. Terpinolene 14. Neryl Acetate 3. b-Pinene 9. Linalool 15. Geranyl Acetate 4. Myrcene 10. Terpinene-4-ol 16. Caryophyllene 5. p-Cymene 11. a-Terpineol 17. trans-a-Bergamotene 6. Limonene 12. Neral 18. b-Bisabolen   Courtesy of Supelco, Inc.     Figure 7 A Chromatogram of Lime Oil

solutes, it is largely a dispersive stationary phase, and thus substances are eluted roughly in order of their boiling points (excepting very polar solutes). The introduction of the diphenyl groups contributes more to phase temperature stability than it does to solute selectivity. The column was 30 m long, 250 mm I.D. carrying a film 0.25 mm thick of stationary phase. Helium was used as the carrier gas at a linear velocity of 25 cm/sec(set at 155˚C). 1. a–Pinene 7. g–Terpinene 13. Geraniol 2. Camphene 8. Terpinolene 14. Neryl Acetate 3. b–Pinene 9. Linalool 15. Geranyl Acetate 4. Myrcene 10. Terpinene–4–ol 16. Caryophyllene 5. p–Cymene 11. a–Terpineol 17.trans–a–Bergamotene 6. Limonene 12. Neral 18. b–Bisabolen   Courtesy of

a sample of lime oil is shown in figure 43. A SB–5 column, that contained poly(5%diphenyl-95%–dimethylsiloxane) as the stationary phase was used to carry out the separation. It is largely a dispersive stationary phase, although the diphenyl group will contribute some induced polarizability capability to interact with polar solutes. As a consequence substances are eluted roughly in order of their boiling points (excepting very polar solutes).   1. a–Pinene 7. g–Terpinene 13. Geraniol 2. Camphene 8. Terpinolene 14. Neryl Acetate 3. b–Pinene 9. Linalool 15. Geranyl Acetate 4. Myrcene 10. Terpinene–4–ol 16. Caryophyllene 5. p–Cymene 11. a–Terpineol 17. trans–a–Bergamotene 6. Limonene 12. Neral 18. b–Bisabolen   Courtesy of