Rose oil the aromatics unaltered by heat. Because CO is gas at normal atmospheric pressure, it leaves no trace of itself in the final product. The equipment for CO extraction is expensive, which is reflected in the price of the essential oils obtained from the process. It takes a large amount of rose petals to distill a small amount of essential oil. Depending on extraction method and plant species, the typical yield can be approximately 1:3,000. To mitigate the cost, some dishonest dealers will dilute rose oil with geranium ("Pelargonium graveolens") or palmarosa ("Cymbopogon martinii") essential oils, both of which are rich
Bergamot essential oil process and allows for the detection of possible adulteration. The combined use of isotope ratio mass spectrometry and SNIF-NMR (Site-Specific Natural Isotope Fractionation-Nuclear Magnetic Resonance) allows discovering adulteration otherwise undetectable even allowing for the identification of the geographical origin of the essential oil. The GC-C-IRMS (Gas Chromatography-Combustion – Isotope Ratio Mass Spectrometer) technique, the most recently used, allows obtaining similar results. Analytical values take as reference for genuinity evaluation of bergamot essential oil by the "Experimental Station for the Industry of the Essential oils and Citrus products", in Reggio Calabria, Italy. The phototoxic effects of bergamot essential oil have been