CONCENTRATION OF TOTAL AL, CR, CU, FE, HG, NA, PB, AND ZN IN COMMERCIAL CANNED SEAFOOD DETERMINED BY ATOMIC SPECTROMETRIC MEANS AFTER MINERALIZATION BY MICROWAVE HEATING

摘要

The concentration of total Al, Cr, Cu, Fe, Hg, Na, Pb, and Zn in commercial canned seafoods (tuna, sardine, jurel, ark clams, mejillons, and common cockles) frequently consumed by the Venezuelan population was spectrometrically evaluated. Flame atomic absorption spectrometry (Fe and Zn), flame atomic emission spectrometry (Na), cold vapor atomic absorption spectrometry (Hg), and electrothermal atomization atomic absorption spectrometry (Al, Cr, Cu, and Pb) were the techniques of choice. Before spectrometric analysis, samples were mineralized by microwave heating, using either Parr-type high-pressure bombs (for Hg and Pb only) or closed vessels with pressure relief valves (for the other metals). Recoveries (95-105%), precision studies (RSD < 3%), and analyses of NIST and NIES standard reference materials demonstrated the reliability and accuracy of the analytical methodologies employed in this study. Metal concentrations were higher in mollusks (edible portion) than in fish (muscle tissue), because bivalves bioconcentrate metals in their tissues. Common cockles showed higher concentrations mu g/g of dry weight) of Al (1168 +/- 175), Cu (4.0 +/- 0.2), Fe (1117 +/- 26), Na (35.9 +/- 1.2 mg/g), and Pb (1.3 +/- 0.1). Mejillons presented the highest Zn concentration (191 +/- 23 mu g/g), while the highest Cr was found in ark clams (1.2 +/- 0.3 mu g/g). Two brands of Venezuelan canned tuna showed Hg concentrations mu g/g) ranging from 1.1 to 1.4, above the Action Level of 1 mu g/g of Hg set by the FDA. These data can be used for referential purposes to judge and control the quality and safety of this type of food.