Water solubility of clary sage essential oil

Abstract

The article provides data on the degree of solubility of essential oils in water. Essential oils are considered as compounds that are completely insoluble or slightly soluble, or refer to substances with a certain, limited, solubility. The distillation of the essential oil from the raw material is preceded by its dissolution in water and hydrodiffusion in the solution beyond the limits of the essential oil containers. The solubility of essential oils in water, apparently, plays an important role in living plants during their intracellular movement and removal outside the cells. To clarify the concepts, samples of primary and secondary oils obtained in production have been examined. The solubility of clary sage oil at 20○C reaches a significant value (0.094% for primary one, 0.406% for secondary one), but with an increase in temperature up to 40○C it decreases to 17-15%. Further study of the GLC data shows that the change in the percentage is due to an increase in the content of cineole and unidentified components in the oil, which have a relatively high solubility, hardly noticeable in the primary oil and accumulate in the secondary one and in the one isolated from the primary one. In the sample isolated from the water solution of the secondary oil there are 2 unidentified components located between cineole and linalool and apparently having increased solubility. Due to this, the percentage of linalool in the oil isolated from the solution decreases, but the absolute amount of the latter in 100 ml of the solution increases 2,58 times compared to the oil isolated from the primary oil solution.