Essential oils (EOs) are complex and unstable compounds processed from aromatic plants including terpenes, alcohols, esters, aldehydes, etc. These oils are commonly used in food, pharmaceutical, and cosmetic industries regarding their natural antioxidant and antimicrobial features. Therefore, the identification and accurate determination of both organic and inorganic contaminants in EOs are becoming increasingly important [1]. In this study, commercially available rose, apricot, jasmine, black cumin, lilac, pine turpentine, orange flower, lavender, thyme, mint, garlic, white rose, jasmine, eucalyptus and vanilla oils were analyzed for their Cd(II) and Cu(II) contents.
The samples were collected from supermarkets. The conventional methods for trace element determinations in oil generally include a sample decomposition and determination by sensitive instrument. This method use solid phase extraction method as a preconcentration procedure. Previously synthesized and characterized magnetite was used as solid sorbent in this method. The preconcentrated sample solutions easily analyzed by relatively less sensitive, cheap and accessible instrument such as flame atomic absorption spectrometry (FAAS) [2]. The preconcentration procedure that was based on solid phase extraction was utilized for separation of analytes and elimination of the oily matrix.
Accordingly, certain amount of essential oil sample was added on 0.26 g magnetite and vortexed for 41 s for sorption of the analytes. Then, oil sample was decanted and excess of the oily matrix on solid phase was removed by washing with n-hexane. Followingly, 6.2 mL of 0.61 mol L-1 HNO3 was added on solid phase and vortexed for 66 s for elution. The results showed that there were significant differences in Cd(II) and Cu(II) concentrations of the investigated oil samples. Additionally, dermatological health risk assessment of these toxic elements were carried out using the calculations Margin of Exposure (MoS), hazard quotient (HQ), hazard index (HI) and cancer risk (CR).