Voltammetric Trace Analysis of Uranium and Other Metals in Meta Rhyolite Rock Samples

Abstract

Direct current polarography (DCP), differential pulse polarography (DPP) and differential pulse anodic stripping voltammetry (DPASV) have been successfully used for the simultaneous determination of trace metals in meta rhyolite rock samples. The polarograms/voltammograms of sample solutions were recorded in 0.1 M KCl, 0.1 M ammonium tartrate and 0.1 M KSCN supporting electrolyte separately. The results indicated the presence of Zn²⁺, Fe³⁺, Mn²⁺, Cu²⁺ and UO₂²⁺ metal ions. Uranium gave a well-defined polarographic wave/peak with E_1/2/E_P -0.26/-0.26 V vs. SCE in 0.1 M KSCN. The method of standard addition was for the quantitative analysis of trace metals, which revealed the following results: Zn²⁺ (22.22), Fe³⁺ (147.10), Mn²⁺ (5.50), Cu²⁺ (28.58) and UO₂²⁺ (0.059) mg g^-1 of the sample. The observed voltammetric results were compared with those obtained using AAS. Statistical treatment of the observed voltammetric data revealed high accuracy and good precision of the determination.