Potentiometric Determination of Silver Nanoparticles using Silver Amalgam Electrodes

A new approach to potentiometric measurements using an advanced amalgam electrode is reported. The conditions for the potentiometric determination on silver solid amalgam electrodes to determine total silver as colloidal silver nanoparticles are described. Proper calibration procedure was demonstrated by the potential and logarithmic concentration dependence at the silver amalgam and reference silver disc electrodes for aqueous silver nitrate, as both electrodes conformed to the Nernst equation with the slopes of approximately +58mV. However, analogous measurements using the silver solid amalgam electrode of silver nanocolloidal solutions provided a slope of -43mV. Although this value did not match the theoretical result for the Nernst equation, the device allowed the determination of total silver in these solutions. Under the same conditions, no useful calibration dependence was obtained using the silver electrode for the silver colloids.