Determination of sulfur species using a glassy-crystalline chalcogenide membrane

A new potentiometric sulfide sensor based on chalcogenide glassy/crystallin e Cu-As2S3 alloys is described. The analytical characteristics of these ion -selective electrodes were fully investigated in terms of sensitivity, sele ctivity, reproducibility and compared to the conventional method for sulfid e determination. Quasi-Nernstian responses associated to a limit of detecti on close to 10-h M were observed. While low selectivity coefficients were o btained versus several anions. The most important characteristic of this se nsor 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 s ulphide concentration in thermal bath. On site measurements show good repro ducibility, long term stability (>3 months) and allow monitoring of sulfide concentration. (C) 2001 Elsevier Science B.V. All rights reserved.