Essential oils: SPE fractionation

Essential oil analysis is often characterised by mixtures that are difficult to separate. The components belong to different classes of compounds that range widely in concentration. Hence, a pre-separation technique is often required, at least to evaluate the minor components. This paper reports an SPE method to overcome this problem. The method was developed with a standard solution that yielded 90 % mean recovery of the analytes. It was then tested on two different essential oils: tarragon (Artemisia dracunculus) and rose (Rosa damascena). In this way, the essential oil components were pre-separated into three fractions: A, which contained hydrocarbons; B, which contained esters, ethers, oxides, carbonyl compounds and tertiary alcohols; and C, which contained other alcohols, acids and diols.