Kinetic Spectrophotometric Determination of Hydroxylamine and Nitrite Ion in a Mixture by Their Reactions with Neutral Red

Kinetic determination of hydroxylamine in soils by the initial rate method is based upon the reaction of neutral red with the nitrite ion, produced by oxidation of hydroxylamine with iodate in acidic media. The optimal conditions for determination are as follows: 0.3 mol L –1 H 2 SO 4 , 0.024 mol L –1 KIO 3 , 6.92×10 –5 mol L –1 neutral red. Hydroxylamine can also be determined in mixtures with nitrite ion, if the nitrite content has been found separately at the same conditions without iodate. The calibration graphs are linear in the range (3–27) μmol L –1 of NH 2 OH and (4–46) μmol L –1 of NO 2 – . The reproducibility errors are 3.3 % and 1.8%, the relative errors of determination prove to be 2.6 % and 2.1 %, for hydroxylamine and nitrite ion, respectively.