Interpretation of (Pu,U) matrix effect on atomization of analytes during GF-AAS analysis

Atomization of Al, Cr, Cu, Cs, Mn, Ni and Sr in (Pu,U) matrix was studied and the effect of Pu/(Pu + U) composition of the matrix on analyte absorbance was investigated. The changes observed in the absorbance signals for the analytes with change in composition of (Pu,U) matrix were correlated with relative oxygen partial pressures of the analyte oxides, UO2, PuO2 and the purge gas. The studies were utilised for the direct determination of trace levels of these analytes in (Pu,U) matrix containing 25 at.% Pu by graphite furnace atomic absorption spectrometry (GF-AAS) with a relative precision of approximately ±10%.