SPECTROPHOTOMETRIC DETERMINATION OF NITRITE IN FOODSTUFFS BY FLOW-INJECTION ANALYSIS

A simple method for the determination of nitrite in foodstuffs by flow injection analysis is described. Nitrite samples are prepared in a mi crowave oven, treated with a 1 mol/l NH4Cl solution at a pH of 9 (all under nitrogen atmosphere) and are immediately analysed. Nitrite is di azotised in the FIA system with N-(1-naphthyl) ethylenediammonium dich loride to form the highly coloured azo dye, which is measured at 540 n m. The detection limit is 0.036 mg/kg for sample injections of 400 mu l. The sampling rate is about 50 samples per hour and the relative sta ndard deviation is 0.67%.