Preparation of a New Solid-State Molybdenum-Selective Electrode and Application

Abstract

A new solid state molybdenum-selective electrode has been developed. The electrode is composed of 20% MoS2, 60% Ag2S, and 20% Cu2S. An analytically useful potential change occurred, from 1 × 10-5 to 1 × 10-1 M molybdenum ion. The slope of the linear portion (1 × 10-1 - 1 × 10-5 M) was about 45 ± 2 mV/10-fold concentration changes in molybdenum. It was found that pH change between 1 and 12 had no effect on the potential of the electrode. There was no interference of most common cations such as K+, Na+, Ca2+, Mg2+, Cu2+ and Fe3+ anions such as Cl-, ,  and . The lifetime of the electrode was more than 2 years, when used at least 4 - 5 times a day, and the response time was about 30 s. This electrode has been used for the determination of molybdenum ion in wine using standard addition method. The validation of the electrode has been made with a commercial molybdenum DP polarography and high consistency was obtained.