Amperometry detection of nitrite in food samples using tetrasulfonated copper phthalocyanine modified glassy carbon electrode

摘要

A stable chitosan protected tetrasulfonated copper phthalocyanine (Chit-TsCuPc) modified glassy carbon electrode (GCE) was used to aid the electrochemical detection of nitrite (NO2−) in food samples. The electrochemical oxidation of NO2−was investigated on bare, chitosan and TsCuPc modified GCE in presence of phosphate buffer solution with an acidic medium. The elevated oxidation peak current was noticed at less oxidation potential for + 0.55 V vs. Ag/AgCl at Chit-TsCuPc modified electrode under the optimized experimental conditions. The plot displays the peak current against NO2−with a good linearity in the concentration rangefrom 6.5 × 10−8 M to 5.0 × 10−10M. The linear regression equation is calculated to be Ip(μA) = 0.5291 + 1.4894C (NO2−), has a good correlation coefficient of 0.9949 and the detection limit of 22 nM (S/N = 3) with the current sensitivity of 4.964 μA nM−1 cm−2. The standard addition method was adopted to measure the unknown NO2−concentration in food samples.