DIRECT ION-SELECTIVE DETERMINATION OF BORON IN GALLIUM-ARSENIDE

The behavior of the Orion fluoroborate-selective electrode (Model 93-0 5) has been investigated under several working conditions. Long respon se time and slow shift of the potential can cause serious difficulties in practical applications. In spite of these facts, after a suitable conditioning of the electrode in solutions whose composition is simila r to that of the solutions of the samples, sufficiently reproducible r esults are possible. Samples of GaAs, containing at least 1 mug/g of b oron, can be analyzed with a precision (relative standard deviation) o f about 5% (n = 5).