Abstract
Reports published on determination of nitrite with, GR reagent (sulfanilic acid, α-naphthylamine and tartaric acid as solid) have been different in the optimum ranges of time, temperature and pH required for its. full coloration. This paper says that the full coloration is maintained during 2080 min. at 1530°C and pH l.93.0 (Figs. 1 and 2). The pH is about 2.3 when 0.1 g of GR reagent is added to a 20 ml sample solution.
Several sulfur compounds and iodide ion interfere with the coloration, but it is proposed that the interferences are simply eliminated by adding 50 mg of mercuric chloride to a 20 ml solution (Figs. 39). If the latter causes precipitate, the filtrate is used for the coloration. Mercuric chloride may be effective also when other similar reagents are used to yield the azo-dye for determination of nitrite (Fig. 10). Thus, it is possible to determine nitrite in hot spring, lake and waste waters containing sulfur compounds and iodide.
