Citronella oil

Description

Citronella oil is present as a repellent in many sprays that contain other repellents, pyrethrins, and synergists. These formulations have insecticidal and repellent actions against biting insects and flies on cattle, dogs, horses, and pigs. The major constituent of citronella oil is citronellal (to which the information below applies).

Chemical properties

colourless or light yellow liquid with characteristic

Chemical properties

Sri Lanka (Ceylon) citronella oil is produced by steam distillation of fresh or partly dried leaves and stems of the grass species Cymbopogon nardus (L.) Rendle – the so-called lenabatu – cultivated in Sri Lanka. It is a pale yellow to brownish liquid with a fresh, grassy, camphoraceous odor.
d²⁰₂₀ 0.891–0.910; n²⁰_D 1.479–1.490; α²⁰_D ?25 ° to ?12 °; solubility: 1 vol in not more than 2 vol of 80% ethanol at 20 ℃; ester number (after acetylation): 157–200; carbonyl number: min. 18, corresponding to min. 5% of carbonyl compounds (calculated as citronellal).The content of citronellal by GC varies from 3% to 6%. Other typical constituents are borneol (4–7%), citronellol (3–8.5%), geraniol (15–23%), and methyl isoeugenol (7–11%).
Sri Lanka (Ceylon) oil is less valuable than Java oil and is used almost exclusively for perfuming toilet soaps, washing powders, and household products. Annual production is only ～25 t.

Chemical properties

There are two essential oils: Ceylon citronella oil and Java citronella oil. Ceylon citronella oil is obtained by steam distillation of the partially dried herb known as the lanabatu variety, while the Java citronella oil is obtained by steam or water distillation of the freshly cut or partially dried herb known as the maha pengira variety. It differs from the Ceylon citronella oil in both composition and odor. The Ceylon type has a characteristic citronellal-like odor. Java-type oil has a pronounced aldehyde (rose, lemon-like) odor.

Physical properties

The Ceylon oil is a pale yellow to yellowish-brown liquid. The Java-type oil is a clear, mobile, light yellow to brownish liquid.

Occurrence

Found in the grasses of Cymbopogon Nardus (Rendle), Andropogon Nardus (L) and Andropogon Nardus Ceylon, de Jong (Fam. Gramineae).

The Uses of Citronella oil

Citronella Essential Oil is the oil extracted from the plant Cymbopogon (lemongrass). It is well-known as an insect repellant.

The Uses of Citronella oil

Soap perfumery, manufacture of hydroxycitronellal, insect repellent.

Definition

Has both d- and l-isomers. C 9H17CHO.

Preparation

By direct steam-distillation of the dried grass.

Essential oil composition

The main constituents of citronella oil are geraniol and citronellal