Solid Microelectrodes for In Situ Voltammetric Measurements

Solid Au and Ag microelectrodes for both, model and in situ voltammetric measurements, have been designed and tested. Amalgamation procedure and the parameters of measurement procedure are discussed. Differences between gold and silver electrodes were studied. Silver electrodes showed more stable behaviour and were used prevalently for calibration and in situ measurements. Calibration of a 30-&micro ; ; ; m diameter Ag electrode for Mn(II), Fe(II), I(-I) and S(-II) showed good linearity with reasonable confidence intervals, necessary for quantification of the signals obtained in situ, with average sensitivity of 0.05, 0.01, 0.16 and 1.10 nA/(&micro ; ; ; mol L-1) and minimal detection limit of 3.5, 28, 0.3 and 0.05 &micro ; ; ; mol L-1, respectively. Additional checking of the electrode sensitivity with the reduction peaks of oxygen is proposed.