Potentiometric titration of sulfanylamide with sodium nitrite.

Abstract

Potentiometric titration of sulfanylamide with sodium nitrite was carried out in the solution acidified with hydrochloric acid, by using seven bimetallic electrode couples; platinum-antimony, platinum-nickel, platinum-palladium, platinum-tungsten, platinum-tantalum, platinum-molybdenum and platinum-silver. The titration curves were constructed and the magnitudes of change in potential at the end point were obtained. The influences of concentration of hydrochloric acid used to acidify the system on them were also investigated. Platinum-tungsten and platinum-palladium electrode couples showed a titration curve with a peak and the potentials at the end point increased abruptly. On the other hand, the other five electrode couples presented an S-shaped titration curve and the potentials at the end point receded suddenly. In case of 1N hydrochloric acid solution, the end points for all couples were not clear. The optimum concentration with respect to hydrochloric acid was 6N. The samples containing sulfanylamide in the range of 40 to 170mg per 55ml solution were titrated directly and satisfactorily by this method. © 1962, The Japan Society for Analytical Chemistry. All rights reserved.