The spectrographic determination of impurities in copper-base samples of small dimensions

Abstract

Serious problems arise in the point-to-point spectrographic analysis of copper-base materials if only wire or thin-sheet samples are available. In the procedure recommended in this paper, the sample is converted into oxide, transferred to a graphite cup of optimum dimensions, then examined spectrographically. Standard oxide samples are prepared in a similar way (from high-purity reagents) and excited, and resulting reference spectra are used to evaluate the impurities in copper, brass, phosphor and aluminium bronze, cupro-nickel, nickel-silver and Everdur. Densities of the recommended impurity lines for each of these materials are in remarkably close agreement at all comparable impurity levels.

The validity of the proposed method has been substantiated by a comparison with similar analytical results obtained by alternative, often time-consuming, procedures.

A wide range of impurities, down to about the 10 p.p.m. level, can be determined in a single sample within 90 minutes, and several samples can be analysed concurrently.