The preparation of water which will not give the yellow coloration with Nessler's reagent is an important problem in the analysis of water. Where the laboratory water supply contains a small quantity of ammonia, suitable water for use in water analysis can no doubt be obtained by ordinary distillation and collecting that part of the distillate which is free from ammonia. The water supply of many laboratories will not permit of this ready method of preparing ammonia free water. The distilled water must be redistilled with sulphuric acid and potassium permanganate to obtain a satisfactory water which will remain colorless when the Nessler reagent is added to it. This method requires distillation in a glass flask and is subjected to the usual degree of breakage and loss.
Proceedings of the Iowa Academy of Sciences
©1902 Iowa Academy of Science, Inc.
Weems, J. B.; Gray, C. E.; and Myers, E. C.
"The Preparation of Ammonia Free Water for Water Analysis,"
Proceedings of the Iowa Academy of Science, 10(1), 112-113.
Available at: https://scholarworks.uni.edu/pias/vol10/iss1/20