Analysis of essential oils of origanum onites by superheated water extraction using gcxgc-tof/ms

Abstract

Superheated water extraction was used to extract essential oils from leaves and grains of Origanum onites. The effect of different sample collection dates on the amount and composition of extracted essential oils was investigated. C-18 solid phase extraction was used to elute the essential oils from the aqueous extract. The volatile components were characterized by comprehensive (two dimensional) gas chromatography with time of flight mass spectrometry (TOF/ MS). The O. onites samples were collected on three different dates (15 June 2006, 25 June 2006, 05 July 2006). The extraction yields from O. onites leaves were 2.88 %, 3.06 %and 3.97 %; and from O. onites grains 3.63 %, 4.22 %and 4.57 %, respectively from each collection date. The main component found in all samples was carvacrol. The later collection dates gave better essential oil recovery from both leaves and grains. © 2009 Taylor & Francis Group, LLC.