Extraction and characterization of essential oil components based on geraniol and citronellol from Java citronella (Cymbopogon winterianus Jowitt)

Abstract

Citronella oil is the main product of Java citronella grass (Cymbopogon winterianus Jowitt) rich in geraniol and citronellol, widely used in mosquito repellents and perfumeries. The age of the plant plays a key role in oil composition and its yield such that young leaves have lesser oil content than the mature leaves. Also, a remarkable difference between fresh and dried leaves regarding oil yield is observed. The various methods of extracting essential oils from citronella grass with respect to yield (%) were studied. Average percent yield in the manual extraction and hydro-distillation procedure was 0.8 and 1 % respectively, which was better as compared to steam distilled oil (0.7 %). The chromatographic analysis of essential oils with respect to standards geraniol and citronellol were studied by high performance thin layer chromatography (HPTLC) with n-hexane and ethyl acetate (3:2) as mobile phase followed by its separation on plates. The developed plates showed geraniol, citronellol and citronellal as major bands. The analysis of all extracted oil samples by means of electrospray ionization-mass spectrometry (ESI-MS) in the positive ion mode showed rapid mass fingerprints of constituents present in the samples according to the observed mass of standards. Furthermore, the analysis of vibrational spectra was accomplished with Fourier transform infra-red spectroscopy (FTIR) specifying all the functional groups as major peaks confirming all of them as monoterpene alcohols with conjugated double bonds. Thus, HPTLC, ESI-MS and FTIR studies evidenced that the two essential oil components were majorly present in the methanol extract suggesting methanol as a good extractant in the manual extraction process.