Determination of platinum, iridium, and rhodium in uranium alloys by atomic- absorption spectrophotometry

Abstract

Platinum, indium, and rhodium, at concentrations of 0.01 to 1 wt% in uranium-matrix alloys, are measured by a rapid atomic-absorption spectrophotomatric method. The alloys are dissolved in hydrochloric and nitric acids (in a sealed tube if indium is involved), and die noble metals are measured in this solution without separation. The uranium effectively suppresses interelement atomic-absorption effects and at the same time enhances the sensitivities of the individual noble metals. The measurement relative standard deviation generally is no greater dian 1% in analyzing alloys containing 0.1 to 1 wt% of noble metals, and no greater than 7% at the 0.01-W.% alloy level.

Determination of rhodium in platinum-rhodium loaded automotive catalyst material by graphite furnace atomic absorption spectrometry

“…For automotive catalyst materials, the use of conventional AAS is severely limited because high concentrations of aluminum and low levels of rhodium would necessitate chemical separations. In addition, several investigators using conventional AAS (7,9) have encountered inter-element effects within the noble metal group. These interferences can be eliminated only by the use of further chemical separations or by the addition of releasing agents such as copper, lanthanum, or uranium to minimize the matrix effects in the flame.…”