Quantitative analysis of several kinds of Ir-Al alloys by ICP-OES

Abstract

For the analysis of samples by inductively coupled plasma-optical emission spectrometry (ICP-OES), dissolution of the samples is important. Classical lead assay, chlorination, fluorination and dissolution with acids are difficult for the dissolution of Ir-base alloys. Therefore, fusion with Na₂O₂ has been used. However, when the alloys are fused with it in a Zr crucible, the crucible is partially dissolved together with Na₂O₂. The dissolved Zr interferes with the measurements of analytes in the samples by spectral interferences of Zr. To dissolve the crucible as little as possible, it was fused with a mixture of 1 g of NaOH and 2 g of Na₂O₂; the amount of Zr dissolved was 20∼130 mg. Salts given by fusion were dissolved in HNO₃-HCl. The analytes in the solution were determined by ICP-OES and the interferences of coexistent elements on the spectral intensities of analytes were corrected by sequential correction method. Good analytical results were obtained for lr-base alloy samples.