Preparation of Graphite Electrodes for Spectrographic Analysis of Acid Solutions

Abstract

A procedure is described for the treatment of graphite electrodes to make them impervious to acids. Elimination of loss of sample due to random seepage into the body of the electrode results in high sensitivity and good reproducibility. Sample volume required is 0 1 ml. Reproducibility obtained is within 25% of the amount present at 0.04 μg/ml level; 0.02 μg/ml is readily detectable for most elements. The electrodes are excited in flowing oxygen. A new compact chamber is also described in which the electrodes are sparked.