Kinetic Spectrophotometric Determination of Nitrite with Tropaeolin 00-Bromate System

Abstract

A simple accurate kinetic spectrophotometric method was developed for the determination of nitrite based on its catalytic effect on the redox reaction between tropaeolin 00 and bromate in acid medium. Nitrite was determined by measuring the decrease in the absorbance of tropaeolin 00 at 530 nm by a fixed time method, after 30 s from the initiation of the reaction. The calibration graph was linear in the range 6–500 ng mL−1 of nitrite and the detection limit was 2 ng mL−1. The proposed method is selective and is useful for the determination of nitrite in drinking water samples.