DETERMINATION OF TRACE-ELEMENTS IN PLANT MATERIALS BY SLURRY SAMPLINGGRAPHITE-FURNACE AAS - SOME ANALYTICAL PROBLEMS

The analytical conditions of cadmium, lead, nickel and cobalt determin ation in plant material by slurry sampling graphite furnace atomic abs orption spectrometry (GFAAS) are presented. The results of stability t ests for slurries prepared in different ways are also shown. The ratio of the amount of analyte found in the liquid phase to the total amoun t of analyte in the slurries is investigated. The determination result s are calculated from aqueous standard calibration graphs (cobalt and nickel) or by the standard addition method (cadmium and lead). Statist ical evaluation of the results from the certified materials indicate t hat the slurry method is both accurate and comparable in precision to the conventional wet-ashing procedure.