Laser-induced fluorescence spectroscopy of certain essential oils by blue and violet diode laser excitation

Laser-induced fluorescence (LIF) spectroscopy of 8 essential oils (rosemary, basil, orange, lavender, peppermint, rose, pomegranate and tea tree oil) has been performed using compact blue and violet lasers operating at 447 nm and 405 nm respectively. The various features of the obtained spectra and their possible molecular origins have been discussed. Important constituents in these oils have been identified, such as two types of chlorophylls (A and B), in addition to a type of tocopherol (vitamin E). It may be possible to roughly estimate, qualitatively, the relative abundance of these constituents in these essential oils. To the best of our knowledge, the analysis of a significant number of essential oils by laser induced fluorescence (LIF) technique has not been performed before. As a future application, the technique can be used for the efficient and rapid detection adulterants in essential oils.