GAS ELECTRODE METHOD FOR DETERMINATION OF AZIDE IN AQUEOUS SAMPLES FROM THE REPROCESSING INDUSTRY

A method has been developed to determine azide (N-3-) in aqueous sampl es from the reprocessing industry using a gas electrode with Teflon me mbrane sensitive to changes in the gaseous hydrazoic acid (HN3) concen tration. The presence of nitrite in mentioned samples gives rise to in terferences from gaseous nitrogen oxides, hence nitrite was eliminated by oxidation with hydrogen peroxide prior to determination, As sample s from the reprocessing industry have a varying matrix, the method of standard additions was used in combination with a fitting method based on linear least squares regression with Mathcad software. The electro de response was linear with the azide concentration from 3 x 10(-6) to 3 x 10(-3) mol l(-1) and the detection limit was about 10(-7) mol l(- 1) azide. Relative standard deviations were between 10 and 20%.