Studies on matrix interference and atomization behavior of Al, Cr, Cs, Cu, Mn, Ni and Zn in Th matrix using GFAAS technique

摘要

An electrothermal atomization atomic absorption spectrometric (ETA-AAS) method with a graphite furnace (GF) atomizer has been developed for the direct determination of Al, Cr, Cs, Cu, Mn, Ni, and Zn in a thorium matrix without prior chemical separation of the matrix. The influence of thorium matrix on the atomization behavior of the analytes and the effects of varying matrix concentrations were investigated. The studies revealed a significant reduction in the analyte signal due to the presence of thorium and its magnitude increased with Th concentration. Multielement solution standards with graded concentrations of the analytes and fixed concentrations of the matrix were used in the standardization process. Based on these investigations, analytical methods were developed for the direct determination of these analytes. The absolute lowest amount determined was, Al and Zn - 5 ng; Cu and Cr - 0.05 ng; Mn - 0.2 ng; and Cs and Ni - 0.25 ng. Repeatability ranged from 4-10% RSD for all of the analytes. Thorium accumulation within the atomizer over its repetitive use did not cause any significant change in the absorbance signals up to 100 atomization cycles. The analytical results were obtained for spiked samples having analytes added at three different concentration levels based upon the analytical ranges established. The estimated values were in close agreement with the added amounts within the range of precision.