COMBINATION OF CLASSICAL DRY ASHING WITH STRIPPING VOLTAMMETRY IN TRACE-ELEMENT ANALYSIS OF BIOLOGICAL-MATERIALS - REVIEW OF LITERATURE PUBLISHED AFTER 1978

Critical statements have appeared recently in the literature concernin g the need for classical dry ashing in trace element analysis of biolo gical materials. In contrast, respected institutions (AOAC, Nordic Com mittee on Food Analysis, etc.) as well as numerous other laboratories have developed, verified, and/or successfully used classical dry ashin g in practical analyses of a number of materials of biological origin. Hence, it is desirable to find out under which conditions the latter decomposition technique yields good and accurate results. Since electr oanalytical techniques are among the most demanding with regard to the completeness of the biological matrix removal, we decided to critical ly review the literature published after 1978 in which classical dry a shing is combined with some version of electroanalytical measurement. It emerged from this review that in particular the charring step requi res careful performing. When performed well, classical dry ashing lead s to complete removal of the organic matrix and to accurate analytical results for a number of determined elements.