Heavy metals content of canned tuna fish marketed in Tabriz, Iran

Some heavy metals are dangerous to health and there is rising concern about the quality of foodstuffs in some parts of the world. Fish، particularly Tuna fish، can concentrate huge quantities of several metals from water and they even play a significant role in human nourishment. In this study، the concentrations of mercury and four trace metals in five brands of canned tuna samples purchased within the Tabriz city (Iran) were determined after digestion via the Association of Official Analytical Chemists techniques. A total of 40 samples were collected. Lead and cadmium levels were determined via graphite tube atomic absorption spectrophoto-metry، whereas nickel and tin levels were determined via flame atomic absorption spectrophotometry، and mercury levels were determined via hydride generation atomic absorption spectro-photometry. The ranges obtained for the elements were Pb (0. 01-0. 242)، Ca (0. 0-1. 05)، Ni (0. 113-0. 589)، Sn (0. 05-0. 9)، and Hg (0. 1-0. 205) mg/kg wet weight. The results showed that tuna fabricated and marketed in Tabriz (Iran) had safe level of heavy metals that were lower than the averages of EC/FAO/WHO levels for these toxic metals.