Preparation and properties of a new solid state arsenate As(V) ion selective electrode and its application.

ABSTRACT

In this study a new solid-state ion selective electrode which is easy to prepare and sensitive to arsenate ion concentration is prepared. The solid salts used in the electrode composition were Cu2S, Ag3AsO4 and Ag2S. The principal component of the electrode was Ag3AsO4. The measurements were made in constant ionic strength using 0.1M NaNO3 and at room temperature. The potentiometric response of electrodes prepared in various compositions was investigated against arsenate ion concentration. The highest slope was obtained with 40% Ag3AsO4, 30% Cu2S and 30% Ag2S. This electrode showed linear response for arsenate ion in the 10(-5)-10(-1) M concentration range. An analytically useful potential change occurred, from 1×10(-6) to 1×10(-1) M arsenate. The slope of the linear portion was about 19±2 mV/10-fold change in arsenate concentration. The lifetime of the electrode was more than two years, when used at least 4-5 times a day, and the response time was about 20-30s depending on the concentration changes. The interference of most common ions and the effect of pH (6-10) have been investigated. This electrode has been used for the determination of arsenate ion in beer sample.