Automated Determination of Ammonia in Natural Freshwaters Using Salicylate-Hexacyanoferrate-Dichloroisocyanurate System

Abstract

An automated method for the determination of ammonia in natural freshwaters was developed with the use of salicylate-hexacyanoferrate-dichloroisocyanurate system. Sodium salicylate is easy to handle and does not produce o-chlorophenol. The use of sodium dichloroisocyanurate as a chlorine donater excludes frequent standarization of chlorine content in sodium hypochlorite solution. Sensitivity in the present method is comparable with that in manual phenol method. The present study suggests that automated salicylate and phenol methods with the need of heating of more than 50°C may not determine the real concentration of ammonia due to the release of ammonia from free amino acids in natural waters.