Kinetic study on the nitrosation of dibenzylamine in a model system

A kinetic study of the formation of N-nitrosodibenzylamine (NDBzA), from the nitrosation of dibenzylamine (DBzA) by sodium nitrite, was performed in a model system under conditions (temperature, pH) that are similar to those encountered in the industrial production of hams processed in elastic rubber nettings. The nitrosation reaction was carried out in a KH2PO4 buffer (0.5 M) at pH 5.8 and at a temperature of 69 degrees C. Since DBzA is insoluble in an aqueous buffer system, a non-ionic surfactant, Tween 20, was used as a solubilizing agent. The nitrosation reaction exhibited first-order kinetics with respect to DBzA and second-order kinetics with respect to nitrite. The calculated rate constant was 4.7 +/- 0.5 M-2/min. The pH profile of NDBzA formation was also determined. The optimal pH of NDBzA formation, 3.12, was close to the pKa of nitrous acid (HNO2, pKa = 3.1).