ABSTRACT
Essential oils are a complex mixture of plant volatile compounds that may contain mainly terpenes and phenolic compounds. These oils find their potential applications in the biomedical field because of their important biological properties (such as antibacterial, antioxidant, antifungal, cancer chemoprotective and allelopathic activities). In addition to their medicinal importance, they are widely used in numerous food, perfume and cosmetic products. Therefore, to take better advantage of these opportunities the physio-chemical characterization of the essential oil is very important. Several analytical methods and techniques such as gas chromatography (GC), high-pressure liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), infrared spectroscopy (IR) and nuclear magnetic resonance (NMR) spectroscopy are available for essential oil characterization. But, due to the volatile nature of constituents present in essential oil, they are preferably analyzed by gas chromatography. However, classical GC alone does not provide enough data for good chemical profiling. Thus to make the GC a better tool for essential oil analysis, advanced GC techniques such as fast GC and chiral selective GC have been used. Nowadays, many hyphenated and multidimensional variants of analytical techniques such as GC-MS, LC-MS, GC-LC, LC-NMR, SFC-GC, etc., are available. This chapter covers fundamental aspects and technological advancement for the chemical characterization of essential oils.
