Analysis and determination of mercury, cadmium and lead in canned tuna fish marketed in Iran

The objective of this study is to determine mercury, cadmium and lead concentrations in 60 canned tuna fish samples produced and distributed in Iran after digestion by the standard methods of the Association of Official Analytical Chemists. Mercury contents in canned tuna fish were determined by cold vapor atomic absorption spectrophotometry while cadmium and lead were determined by graphite furnace atomic absorption spectrophotometry. The metal contents, expressed in μg g-1wet weight for mercury, cadmium and lead varied from 0.010 to 0.401 (average of 0.125), 0.008 to 0.150 (average of 0.050) and 0.021 to 0.301 (average of 0.096), respectively. The values  were comparable and in the range of the literature values. The results of this study indicate that tuna fish produced and marketed in Iran have concentrations well below the standards of FAO/WHO levels of these toxic metals.Key words: Canned tuna fish, heavy metals, mercury, cadmium, lead