A simple solid-state pH electrode based on Ag/AgCl-Cu

Abstract

The protonic sense materials have been screened from our laboratory for development to microprobe electrodes. The basic measurement was based on potentiometric method using reference electrode and indicating electrode. The materials tested were aluminum-copper, platinum-carbon, silver/silver chloride-carbon, silver/silver chloride-copper and silver-aluminum. The potential measurement in mV unit of test solutions with various pH found that at least one proton contains 59 mV/pH range. The selectivity of materials to proton can be seen from the graph plotted between pH and mV count. The commercial glass electrode was used as comparing electrode and it showed the linear equation of y = -58.00x + 392.1 with r2 = 0.999. The silver/silver chloride-copper probe was found to be the protonic sense material which provided linear equation of y = -25.07x ??? 73.69 with r2 = 0.931. The selected solid-state pH electrode was applied to use as pH sensor for monitoring of pH of natural water collected between February and April, 2009. Data were analyzed statistically using Student???s t-test and it was found that the results obtained from both pH meter coupled with the selected solid-state pH electrode are not significant different at 95 % confidence levels.

Keywords: solid-state pH electrode; miniaturization; protonic sense