Detecting Essential Oil Adulteration
An upsurge in worldwide essential oil sales seems to have intensified corrupt practices by unscrupulous costcutters and adulterators with varying levels of expertise. From outright misrepresentation of botanical species to the addition of cheaper oils to create additional profit for the oil producer, adulteration is unfortunately a common place occurrence in essential oil trade. The most adulterated essential oils fall into two categories: high-value oils like sandalwood and rose and the bestselling oils such as lavender, peppermint, citrus oils, wintergreen, oregano, and thyme. While some adulterations can be detected simply by routine GC-MS testing, with technology such as GC-IRMS and SNIF-NMR, analysts are able to spot adulteration with synthetic compounds or the natural compounds and/or oil fractions taken from cheaper essential oils. Today’s cutting-edge technology for essential oil adulteration detection encompasses many analytical techniques from HPLC and fast GC to GC × GC, IRMS to MS, 1H, and 13C NMR. This paper is a review of 30 studies dating up to May 2014 that detail the analytical procedures used to uncover essential oil adulteration in order to ensure that essential oils are authentic and genuine.