Kinetic determination of trace amounts of nitrite based on its inhibitory effect on the photochemical reaction between iodine and ethylenediaminetetraacetic acid

Abstract

A kinetic method for the determination of trace amounts of nitrite based on its inhibitory effect on the photochemical reaction between l₂ and EDTA (6 × 10^–5M l₂, 2 × 10^–4M EDTA, pH 5, 40 °C and 2000 lux) is reported. The reaction is monitored amperometrically (Pt-SCE, 100 mV) by measuring the time required for the current due to iodine to decrease to zero. Nitrite can be determined at concentrations between 3 and 100 ng ml^–1. The proposed method has been applied to the determination of nitrite in waste waters and alkaline nitrates.