title: Nitron as a titrant in potentiometric determination of nitrate.
abstract: A volumetric method of nitrate determination has been developed, using nitron as a titrant and detecting the end-point potentiometrically with a membrane electrode sensitive to nitrate. To get a better insight into the characteristics of the system, the acid dissociation constant of nitron was evaluated spectrophotometrically (pK(a) = 10.34). The solubility product of nitron nitrate was found to be 1.78 +/- 0.03 x 10(-6) (20 degrees , 0.05M K(2)SO(4)). The optimal nitrate concentration for titration is about 0.01M and this method may be successfully applied for determination of nitrate nitrogen in fertilizer samples.
authors.affiliation: Institute of Fundamental Problems in Chemistry, The University, Warsaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Hulanicki
authors.forename: M
authors.initials: M
authors.lastname: Maj