Determination of Nitrite by Flow Injection Spectrophotometry Using a Home-made Flow Cell Detector

Abstract

A simple, rapid, low cost and accurate determination using flow injection spectrophotometry with a home made flow cell detector, in combination with green LED and photodiode, had been developed for nitrite based on the Griess-Saltzman reaction, measuring the absorbance at 525 nm. The proposed system is able to monitor nitrite in freshwater samples at a throughput of 60 samples per hour with a relative standard deviation (%RSD) of less than 2.4% and a detection limit of <7 μg dm^-3. The calibration graph was linear between 0.010 - 1.0 mg dm^-3.