Nitron as a titrant in potentiometric determination of nitrate.
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.
Hulanicki
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Institute of Fundamental Problems in Chemistry, The University, Warsaw, Poland.
Maj
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