Comparison of the Cloud Point Extraction and Matrix Volatilization Procedures for the Determination of Cr, Cu, Fe, Ni, and Pb in a Germanium Matrix by Graphite Furnace Atomic Absorption Spectrometry

摘要

Two procedures are compared for the determination of critical impurities (such as Cr, Cu, Fe, Ni, and Pb) in a germanium matrix. The first procedure involves a cloud point extraction procedure that uses the Ammonium pyrrolidine dithiocarbamate (APDC) - Triton X-114 system and the second procedure uses a matrix volatilization technique for the removal of the germanium matrix using chlorine gas. Graphite furnace atomic absorption spectrometry (GFAAS) was used for the determination of the impurities. Preconcentration factors between 75.0-91.5 times were obtained using the cloud point extraction procedure (CPE) for all of these impurities. Using the volatilization technique results in lower factors of preconcentration. The limits of detection obtained by CPE were 0.015 mu g/g for Cr, Cu, and Ni and 0.024 mu g/g for Fe and Pb. However, by using the matrix volatilization procedure, the limits of detection were 0.1 mu g/g for Cr and Ni and 0.14, 0.33, and 0.16 mu g/g for Cu, Fe, and Pb, respectively.