Determination of sulfur species using a glassy-crystalline chalcogenide membrane

A new potentiometric sulfide sensor based on chalcogenide glassy/crystalline Cu–As2S3 alloys is described. The analytical characteristics of these ion-selective electrodes were fully investigated in terms of sensitivity, selectivity, reproducibility and compared to the conventional method for sulfide determination. Quasi-Nernstian responses associated to a limit of detection close to 10−6 M were observed. While low selectivity coefficients were obtained versus several anions. The most important characteristic of this sensor was the ability to detect the sulfide species at neutral or pH or even acidic pH. The sensor was applied to the long term in situ monitoring of sulphide concentration in thermal bath. On site measurements show good reproducibility, long term stability (>3 months) and allow monitoring of sulfide concentration.