Flow Injection Analysis of Sulfide Using a Cinder/Tetracyano Nikelate Modified Screen-Printed Electrode

Flow injection analysis (FIA) of sulfide is presented using a screen-printed carbon electrode modified with a cinder/tetracyano nickelate hybrid (designated as cinder/NiTcSPE). Hybridization of NiTc was achieved in iron-enriched industrial waste cinder material through the bimetallic formation of FeIII[NiII(CN)4]. The electrocatalytic oxidation of sulfide is mediated by the higher oxidation state of Ni in this hybrid-bimetallic complex. The system shows a detection limit (S/N=3) of 0.06 μM and a linear working range up to 1 mM in pH 10, 0.1 M KCl solution. Taking into account the relatively low volatility of the analyte in alkaline conditions, the system is ideally suited for the accurate detection of sulfide. The response of the electrode to sulfide is highly reproducible, thereby offering the potential development of a disposable amperometric sensor for sulfide. Selective detection of sulfide in cigarette smoke is presented in this study as an example of a real sample application.