(656d) Essential Oil with Therapeutic Potential: Solubility in Compressed CO2

Previous work have shown that essential oils such as tea tree oil, lavender oil and lemon oil may act as acaricides, antimicrobial agents or antiseptic agents.  Liquid and supercritical CO₂ may be a useful vehicle for delivery of these agents in a variety of indoor environments.  Tea tree oil (TTO) is the essential oil steam-distilled from Metaleuca alternifolia, an Australian native plant.  Several in vitro studies have investigated its antimicrobial properties and in recent years, TTO has become popular as a naturally occurring antimicrobial and antiseptic agent.  Lavender oil is an essential oil obtained by distillation from the flower spikes of certain species of lavender.  Like all essential oils, it is not a pure compound but a mixture of naturally occurring phytochemicals, including linalool and linyl acetate. Lemon oil is an essential oil extracted from lemon peels. Lemon oil is used in many personal care products, home cleaning products and furniture polishes.  Constituents of lemon oil include limonene, which is responsible for the aroma and citral, for what we recognize as the lemon note in the aroma profile.  We report the solubility of tea tree oil, lavender oil and lemon oil in compressed CO₂ at several temperatures and pressures.  The Peng-Robinson equation has been used to model the phase behavior of each binary system.