Photometric determination of ammonium. • Photometric determination as indophenol. • At a pH value of about 12.6 ammonium reacts with hypochlorite and salicylate in the presence of sodium nitroprussiate as catalyst to form a blue indophenol. • Type: standard test 1-05 • Ranges: » 10 mm cuvette: 0.1 - 2.5 mg/l NH4+ / 0.1 - 2.0 mg/l NH4-N » 50 mm cuvette: 0.01 - 0.50 mg/l NH4+ / 0.01 - 0.40mg/l NH4-N • Sufficient for: 100 determinations • Sea water suitability: no