Spectrometric evaluation of the metal content in canned tuna

We present the spectrometric determination of aluminum, copper, iron, mercury, lead, sodium and zinc in a commercial canned tuna product (EVEBA). Two microwave-based mineralization procedures were developed, using either closed vessels with pressure relief valves or high pressure reactors. No significant differences (P > 0.001) were obtained between the metal levels found for the two-digestion procedures. The mercury concentration found in the canned tuna samples (i.e, 1.5 plus or minus 0.1 mu g/g) was higher than the recommended by the World Health Organization (ca. 0.5 mu g/g) in fish. The detection limits, definded as three times the standard deviation of the blank, were 40 mu g/L aluminum, 20 mu g/L copper, 70 mu g/L iron, 53 ng/L mercury, 0.1 mu g/L lead, 20 mu g/L sodium and 14 mu g/L zinc.