COMPARISON OF 2 MINERALIZATION METHODS FO R DETERMINATION OF LEAD BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY - APPLICATION TO SOILS, VINE-LEAVES, GRAPES, MUSTS, RAPES AND LEES SAMPLES

Two methods for the determination of lead based on graphite furnace at omic absorption spectrometry (GFAAS) are described. The essential diff erence between the methods resides in sample mineralisation: microwave system digestion versus dry ashing. The repeatability of the two meth ods has been tested by analysing three reference materials with lead c oncentrations varying from 19 mug/kg to 349 mg/kg. Although the two me thods examined for wine and vine products do not offer notable differe nces (except earth samples), our choice is inclined to the microwave d igestion which conducts to the best results, with relative standards d eviations of maximum 5% connected to a considerable gain of time: 30 m in instead of 20 h. This method can be applied to the trace and ultra- trace elements analysis in food and beverages; its validation accordin g to CEE rules of conduct is desirable and will be realised subsequent ly.