Use of the sulfide minerals pyrite and chalcopyrite as electrochemical sensors in non-aqueous solutions. The potentiometric titration of weak acids in alcohols

Abstract

Natural monocrystalline pyrite and chalcopyrite were examined as new indicator electrodes for the potentiometric titration of weak acids in tert-butanol and iso-propanol. The electrodes investigated demonstrated a linear dynamic response for p-toluenesulfonic acid concentrations in the range from 0.1 to 0.001 M, with a Nernstian slope of 48 mV per decade for pyrite in tert-butanol. Sodium methylate, potassium hydroxide and tetrabutylammonium hydroxide (TBAH) proved to be suitable titrating agents. The response time was less than 12 s and the lifetime of the electrodes was higher than 1 year. The advantages of the electrodes are long-term stability, rapid response, reproducibility, easy preparation and low cost.© Versita Warsaw and Springer-Verlag Berlin Heidelberg.

Synthesis of a Novel Sensor Electrode Based on Bromothymol Blue as an Indicator Electrode in Potentiometric Acid-Base Titration in Aqueous Solution

“…Different types of electrode have been used as acid-base indicator electrodes. Of those, the most frequently used are the titanium, hydrogen-palladium and other electrodes [9][10][11][12].…”

“…To study the thermal stability of the sensor, calibration graphs were constructed at different test solution temperatures 15, 25, 35 and 45 C. According to Figure 6. The sensor would be used for pH measurements in the range from (2)(3)(4)(5)(6)(7)(8)(9)(10)(11). At lower temperatures, like 283 K, the slope of the sensor was about 34.12 mV/decade.…”

A Spin Coating of Thymol Blue Indicator on F-SnO2 Glass to fabricate a Novel Sensor Electrode in Potentiometric Acid-Base Titration

“…Titrimetric procedures based on a detection of the endpoint, i.e., the point at which volumetric titration is completed, are successfully employed over a wide range of concentrations and are popular because of their simplicity, speed, accuracy and good reproducibility [9]. Recently, many studies developed some types of electrodes in potentiometric acid base titration [10][11][12][13]. Thymol blue (thymolsulphonephthalein) is used as a pH indicator.…”