VOLTAMMETRIC DETERMINATION OF ETHYL NITRITE

Abstract

The possibility of voltammetric determination of ethyl nitrite on a graphite electrode modified with carbon ink was investigated and described in this study. The physicochemical characteristics of the oxidation process of the compound were studied. A nonlinear dependence of the oxidation current of С2Н5ONO on the scan rate was obtained. This indicates the absence of adsorption on the surface of the electrode. The dependence of the peak current on v 1/2 and the dependence of the potential of the ethylnitrite oxidation peak on log(v 1/2) are linear, indicating that the process is irreversible. The electrochemical behavior of ethyl nitrite on a graphite electrode modified with carbon ink, using voltammetry, has been studied. The effect of various factors on the anode signal of alkylnirite was shown: pH, time and potential of accumulation, potential scan rate. Oxidation of C2H5ONO strongly depends on the pH of the background electrolyte and when the pH is shifted to a neutral and alkaline medium, the current decreases as the number of protons is not sufficient to oxidize nitrite. The maximum current for the electro-oxidation of ethyl nitrite was obtained in an acidic environment. A universal Britton-Robinson buffer solution with pH 4.02 was used as a background electrolyte. The working conditions for the determination of ethyl nitrite in model media were selected: pH 4.02; Eacc 0.4 V; tacc 4.0 s; v = 100 mV∙s-1. The linear regression equation of ethyl nitrite was obtained at a potential of 1 V, in the range of concentrations of 1-10∙10-6 mol∙l-1. The detection limit was 3.8·10-7 mol∙l-1. Thus, a simple and rapid method for the determination of ethyl nitrite with high sensitivity has been developed.