Dissolution method with HBr-Br₂ for the analysis of Mn-Rh alloys by inductively coupled plasma-optical emission spectrometry

Abstract

A new dissolution method of a Mn-Rh alloy including trace amounts of Al and Si has been developed for the precise analysis by inductively coupled plasma-optical emission spectrometry (ICP-OES). For the determination of Mn, Rh, Al and Si in Mn-Rh alloy samples (100 mg), the samples were dissolved with 20 ml of HBr-Br₂, followed by the addition of 20 ml of HClO₄ at room temperature; then, most of HBr was decomposed into Br₂ with drops of H₂O₂. The resulting solution was concentrated to about 10 ml after the addition of 10 ml of HNO₃, and MnO₂ was decomposed with H₂O₂ after adding 10 ml of HCl (1+1) and 10 ml of H₂O to obtain a clear solution. Si was determined by a gravimetric method. Moreover, after being measured by ICP-OES, the analytical results were estimated with the sequential correction method.