Quality profile determination of Chios mastic gum essential oil and detection of adulteration in mastic oil products with the application of chiral and non-chiral GC-MS analysis

The determination of mastic oil profile, with emphasis on its chiral characteristics, could serve as a method for detecting adulteration in products found in the market with a claim of mastic oil content aiming towards protecting it from counterfeiting. Furthermore the evaluation of the raw material is crucial, as the profile is potentially affected by factors as mastic origin and storage time. Thus 45 authentic mastic oil samples were analyzed by GC-MS employing a chiral column and content limits for all major constituents were determined. The chiral GC-MS analysis proved that selected concentration ratios between these constituents, namely those of (-)/(+)-α-pinene (≤1:100) and (-)-α-pinene/myrcene (1.9:100-11:100) could serve as markers for the determination of mastic oil authenticity. Employing this methodology, the analysis of 25 mastic oils contained in cosmetic and dietary products, as well as an artificial mastic oil sample, exhibited several differentiations that could indicate adulteration either with artificial essential oils or volatile compounds, or the use of aged mastic oil.