Electrochemical sensor for simultaneous determination of dextromethorphan hydrobromide and paracetamol at carbon paste electrode modified with synthesized indium tin oxide nanoparticles and ionic liquid

Indium tin oxide nanoparticles were synthesized by solution route using cetyltrimethyl ammonium bromide as surfactant and used as a modifier of the electrode. An electrochemical study for simultaneous quantification of dextromethorphan hydrobromide (DXM) and paracetamol (PA) by adsorptive stripping differential pulse voltammetry at a carbon paste electrode modified with the composite of indium tin oxide nanoparticles and 1-butyl-3-methylimidazolium chloride ionic liquid (ITO-IL-CME) is described. Phosphate buffer (0.05 M) at pH 7 was found to be the ideal supporting electrolyte for the electrochemical study. The voltammetric results indicate that ITO-IL-CME remarkably enhances the electrocatalytic activity towards the oxidation of DXM and PA in neutral solution. The peak current increased linearly with the concentration for DXM in the range from 9.70 x 10(-7) M to 6.20 x 10(-4) M with a correlation coefficient of 0.989 and for PA with the concentration in the range from 3.62 x 10(-8) M to 7.18 x 10(-4) M with a correlation coefficient of 0.995. The detection limits for simultaneous determination of DXM and PA were 4.66 x 10(-8) M and 8.40 x 10(-9) M for DXM and PA respectively. The proposed procedure was successfully applied for determination of the drugs in pharmaceutical formulations, human serum and urine sample with good apparent recoveries without interference from matrix. The nanocomposite material modified carbon paste electrode has several advantages such as providing improved voltammetric behavior, long time stability, good selectivity, high sensitivity and excellent reproducibility.