Amperometric detection of sulfide: An electrocatalytic reaction with ferrocene carboxylate

The electrocatalytic oxidation of sulfide and sulfhydryl thiol species by ferrocene carboxylate at both glassy carbon and boron doped diamond electrodes is examined. The enhancement in the oxidative current recorded in the presence of sulfide, allowed linear ranges up to 1 mM for sulfide detection to be achieved. In the absence of the mediator, no defined oxidation wave was observed for the direct oxidation of sulfide. Furthermore, the use of hydrodynamic voltammetry produced a limit of detection of 2 mu M. The procedure was applied to the recovery of a sulfide spike in river water, with a recovery of 104% obtained.