Air-Cooled Electrodes for the Spectrochemical Analysis of Powders*†‡

Publisher Website
Google Scholar
Abstract
A controlled source of excitation has been developed to eliminate selective volatilization and element interference effects encountered in the spectrochemical analysis of powders with the dc arc. A circular air jet, concentric with the sample electrode, was used to cool the unburned portion of the sample throughout the exposure and to stabilize the arc by surrounding it with a directed current of air. The effectiveness of the air jet was increased by placing the samples in deep narrow craters drilled in high-purity graphite electrodes. Uniform volatilization of even the volatile constituents was achieved and the spectral sensitivity of the elements was made relatively independent of the sample matrix. A maximum deviation from the mean of less than a factor of two was obtained for the sensitivity of any element when determined in a number of matrix materials including graphite, SiO2, NaCl, Al, and Zn. A significant improvement was made in the linearity of the intensity-concentration curves.

This publication has 4 references indexed in Scilit: