Electrochemical determination of trace sulfur containing compounds in model fuel based on a silver/polyaniline-modified electrode†
A modified electrode (GCE/PAni/Ag) was used for the electrochemical detection of sulfur containing compounds (SCCs) such as benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in the presence of naphthalene (NP), thiourea (TH) and carbazole (CR). The electrochemical response of BT, DBT and 4,6-DMDBT was determined using the differential pulse voltammetry (DPV) method. The detection range for SCCs was from 1 to 11 ppm with detection limits (LOD) of 0.33 ppmS, 0.24 ppmS and 0.21 ppmS for BT, DBT and 4,6-DMDBT, respectively. The electrochemical sensor showed excellent selectivity for the compounds in the presence of naphthalene, carbazole and thiourea over the studied range of concentrations. The prepared electrode showed satisfactory reusability data even after four successive measurements. From this study, it can be seen that GCE/PAni/Ag can be used to assay SCCs in petroleum samples.