Gaseous nitrogen trichloride sampling and analyzing method for atmosphere of e.g. swimming pool, involves reacting chloride ions with reagents to form ferrithiocyanate ions, and measuring ferrithiocyanate ions by spectrophotometry

摘要

The method involves passing a determined volume of gaseous mixture through a filter (5) impregnated with sulfamic acid, to retain chloramine and hypochlorous acid. The volume is passed through a filter (4) to retain gaseous nitrogen trichloride. The retained nitrogen trichloride is reacted with a reagent to decompose the nitrogen trichloride into chloride ions, in the presence of water. Ions are reacted with reagents containing respective ferric ions and mercury thiocyanate, to form ferrithiocyanate ions from the chloride ions. The ferrithiocyanate ions are measured by spectrophotometry.