ABSTRACT
Essential oils (EO) are a multi-component mixture of different chemical constituents like terpenoids, flavonoids, glycosides, etc. It is generally difficult to characterize essential oils. Essential oils are basically characterized by their flavor and fragrance, stability, chemical constituents, etc. Gas chromatography (GC) is not sufficient to generate efficient chemical evidence of essential oils; therefore, GC associated with Fourier-transform infrared spectroscopy (FT-IR) and mass spectroscopy (MS) have been reported for effective characterization. These sophisticated methods for identifying EO have been documented viz. Mexican marigold (Tagetes minuta), cumin (Cuminum cyminum), caraway (Carum carvi), fennel (Foeniculum vulgare), ginger (Zingiber officinale), garlic (Allium sativum), basil (Ocimum L.), coriander (Coriandrum sativum), cinnamon (Cinnamomum camphora), cumin (Cuminum cyminum), and Indian mustard (Brassica juncea). More than 96 constituents in the essential oil of Cinnamomum camphora have been identified using GC connected with conjunction with time-of-flight mass spectrometry (TOFMS). The several cutting-edge techniques to ascertain the essential oil specification include the MAU-9 electronic nose (e-nose), gas chromatography-flame ionization detector (GC-FID), high-pressure liquid chromatography (HPLC), HPLC-MS, and HPLC-GC. The author of this chapter places a strong emphasis on the most recent methods for characterizing the chemical properties of distinct essential oils and their medicinal formulation.
