Determination of trace nitrite in water samples by catalytic spectrophotometry

A kinetic spectrophotometer method has been developed for the determination of copper. It is based on the reaction of discoloring oxidation between dimethyl yellow and potassium bromate catalyzed by copper in acid medium. The influential factors of reaction and the optimum conditions for the determination of nitrite were investigated. The linear determination range is between 0. 5 and 5. 0 μg /25 mL of nitrite. A detection limit of 2. 39 × 10- 9g / mL NO-2 is achieved. The relative standard deviation is 1. 02% and the recovery of samples is 98. 2%. The method has been applied to the determination of nitrite in water samples with satisfactory results.