Modified carbon-paste-surface electrode for NaCl and KCl solution measurements

In this work, we report on the research results of electrical impedance spectroscopy using a surface printed electrode with superficial modification using graphite nanoparticles and polymethyl-metaacrylate in three concentrations. The experiments used saline solutions of NaCl and KCl with a molar range between 0.287 to 3 M. Three parameters with nonlinear behaviour were used to adjust the molar concentration (MC); the correlation coefficients show a higher relationship (r ²  >  0.9). This behavior depends on frequency, graphite and MC. The proposed electrode was found to have lower sensitivity to lower levels of NaCl or KCl which, in turn, might be a good electrical characteristic in order to detect a higher concentration in a solution. The modified electrode has advantages such as low cost, easy construction and lower saturation surface; future application of this sensor could be an industrial process or corrosion with brine water. (paper)