The Mediated Detection of Hydrogen Sulfide in Room Temperature Ionic Liquids

The detection of H2S was studied using several mediators in room temperature ionic liquids (RTILs) at a microelectrode. Each mediator was characterised voltammetrically. and H2S was added to observe if any mediation took place. A successful mediator was 3,5-tert-butyl-obenzoquinone. Cyclic voltammetry was carried out in [C(2)mim][NTf2]. A reductive wave was observed and attributed to the two-electron reduction of the mediator. No oxidative signal was observed. H2S was flowed through the system. Cyclic voltammograms showed a decrease in the reductive wave of the mediator and the onset of an oxidative signal due to the reaction between the mediator and H2S to form an adduct. This reaction is reversible and on purging the system with N-2, the original reductive signal of the mediator was recovered.