Analytical Strategy Overview to Identify Vegetable Oil Adulteration in Essential Oils: The Cypriol ( <i>Cyperus scariosus</i> L.) Essential Oil Workcase

ABSTRACT Vegetable oil adulteration in essential oils is a common practice to increase artificially the volume of production of these natural raw materials and reduce the production cost. With the case study of cypriol oil, an overview of the different analytical tools was established to identify the fraud. The analytical strategy implemented analytical approaches suitable for the detection of heavy compounds such as triglycerides in vegetable oils to detect at least 3% of addition. This methodology includes stable isotope analyses IRMS δ 13 C, thermogravimetric analyses, spectroscopic techniques (FTIR and NMR) and the study by GC–MS (high temperature columns and derivatization). Depending on the adulteration performed, some techniques will be more effective. δ 13 C measurement is useful for the authentication of essential oils from C 4 plants; thermogravimetric analysis is the simplest to implement and allows for a quick detection of fraud but does not allow for the identification of the adulterant, in which case a complementary spectroscopic analysis will be necessary.