ANALYSIS OF VOLTAMMETRIC ItALF-WAVE POTENTIALS IN LOW IONIC STRENGTH SOLUTIONS AND VOLTAMMETRIC MEASUREMENT OF ION IMPURITY CONCENTRATIONS

0') An analytic equation is presented that allows the prediction of steady-state voltammetric half-wave potentials as a function of electrolyte concentration in low ionic IrNj strength solutions for electrodes of arbitrary geometry and size. The equation istested for the oxidation of ferrocene and reduction of TCNQ in acetonitrile at 2.4- 22.1 Amplatinum. microdisk electrodes for olectrolyte (tetra-n-butylammonium perchlorate) co cntrations between"10 and 4 x(10-,.M, and in acetonitrile solutions containing no intentionally added electrolyte- An analytical method for measuring ion impurity concentration, based on steady-state microelectrode voltammetry, is proposed and used to measure ionic impurities in acetonitrile. The role of ionic solution impurities on voltammetric measurements in the absence of intentionally added electrolyte is quantified and a criterion for the minimum.................... number of ions required to observe sigmoidally-shaped voltammetric curves at microelectrodes is proposed. t,diia:)ility Codes tvail a!d l o