COMPARISON OF DRY MINERALIZATION AND MICROWAVE-OVEN DIGESTION FOR THE DETERMINATION OF ARSENIC IN MUSSEL PRODUCTS BY PLATFORM IN FURNACE ZEEMAN-EFFECT ATOMIC-ABSORPTION SPECTROMETRY

Two digestion procedures were compared in order to obtain an accurate method for the determination of As in mussel products using platform in furnace Zeeman-effect atomic absorption spectrometry. One procedure was based on dry mineralization of the samples and the other on microwave-oven sample digestion in closed polytetrafluoroethylene reactors. Microwave-oven digestion with HNO3 and H2O2 allows the accurate determination of As in certified oyster and mussel tissue samples and provides results comparable to those found by dry mineralization of real mussel product samples, with a sensitivity of 3.9 absorbance units per mu-g ml-1 and a relative standard deviation of 5% in the analysis of samples containing 8-mu-g g-1 dry mass of As. Experimental conditions for the determination of As in real samples were optimized and a series of real samples analysed in order to determine the analytical characteristics of the proposed procedure. Sample treatment time was reduced from 2-3 d using dry mineralization, to 20 min per sample using microwave-oven digestion.