The assessment of Omega-3 fish oil pollution with mercury derived from shark and tuna fish in post-market surveillance in Tehran by cyclic voltammetry

Fish oil is one of the best sources of fatty acids dietary supply. Recently, use of fish oil is enhanced based on its useful effects on human health. Unfortunately, due to industrial pollution, many fish and fish oils have high levels of mercury. Mercury is one of the most poisonous microelement for the ecosystem. mercury is toxic and can damage the brain and the nervous system. The main object of this research was the assessment of Omega-3 fish oil pollution with mercury derived from shark and tuna fish in post-market surveillance in Tehran by cyclic voltammetry. For this pupose fourteen fish oil brands was collected from market retail and transferred to the laboratory. In this research, closed vessel microwave extraction and cyclic voltammetric method was employed. The digestion process was perfomed via four steps in a constant 50 bar pressure and a gradiant temperature from 145 to 200 ˚C. The mercury content of fish oils was in the range of 11.03–107.11 ng/ml. Validation of parameters reveal that the precision of developed method was 2.3 percent in mean standard deviation. In conclusion, fish such as swordfish and shark and tuna fish are also a source of exposure to the heavy metal toxin, mercury. So the potential toxicity of omega 3 fish oil capsules with mercury must be considered and it is necessary to measure the mercury content of these capsules with a simple, precise, accurate and economic method.