Spectrophotometric determination of micro amounts of nitrogen as indophenol

摘要: A critical study has been made of the well known spectrophotometric determination nitrogen as ammonia, originally based on reaction ammonia with hypochlorite and phenol producing a blue coloured indophenol.This resulted in modified method gain sensitivity reproducibility.The absorptivity indophenol found this is 0·60 per p.p.m. cm at wavelength 625 nm, which an improvement methods previously reported.The standard deviation 0·0013 0·2 level 50 ml colour developed solution. The solution obtained after development also suitable for solvent extraction isobutyl alcohol. described paper can be applied to 0·05 20 µg nitrogen.