Investigation of trace metals in different varieties of olive oils from northern Cyprus and their variation in accumulation using ICP-MS and multivariate techniques

Determination of trace metals in olive oil is an essential aspect for the assessment of good quality of dietary oil. It is so, because heavy metals are known to have a negative effect on the oxidative rate of the oils and be toxic to its consumers. This study is the first to be carried out in northern Cyprus aimed at determining the content of copper (Cu), cadmium (Cd), chromium (Cr), arsenic (As), lead (Pb), and nickel (Ni) in different varieties of olives in the region. The analysis was carried out using inductively coupled plasma mass spectrometer following microwave digestion with nitric acid and validated using an oil reference material. Two multivariate statistical analysis (principal component and agglomerative cluster analysis) used for the modeling and classification of different varieties of olive oil produced in the northern region of Cyprus. The metal concentrations are: Cu 1.02–3.81, Cd 0.02–0.09, Cr 0.33–0.95, As 0.03–0.75, Pb 0.15–1.48, and Ni 0.22–0.79 (minimum–maximum in µg/g). The content of Cu was observed with a high concentration of about 87% of all varieties of olive oils, while Pb, Cr, and As have a notable amount in a few of the varieties as compared to the standard limits by FAO/WHO expert committee on food and addictives and US environmental protection agency. Other metals like Ni and Cd are found to be tolerable in all the varieties of olive oils.