Electrochemical study and flow-injection amperometric detection of trace NO2 at CuPtCl6 chemically modified electrode

A thin film of mixed-valent CuPtCl6 is deposited on a glassy carbon electro de by continuous cyclic scanning in a solution containing 3 x 10(-3) M CuCl 2 + 3 x 10(-3) M K2PtCl6 + 1 M KCl in the potential range from 700 to -800 mV. The cyclic voltammetry is used to study the electrochemical behaviors o f nitrite on CuPtCl6/GC modified electrode and the electrode displays a goo d catalytic activity toward the oxidation of nitrite. The effects of the fi lm thickness, pH, the electrode stability and precision have been evaluated . Experiments in flow-injection analysis are performed to characterize the electrode as an amperometric sensor for the detection of nitrite. The modif ied electrode shows a wide dynamic range, quite a low detection limit and s hort response time. The linear relationship between the flow-injection peak currents and the concentrations of nitrite is at a range of 1 x 10(-7)-2 x 10(-3) M with a detection limit of 5 x 10(-8) M. (C) 2000 Elsevier Science B.V. All rights reserved.