Modified multiwalled carbon nanotubes paste electrode as a sensor for the electrocatalytic determination of N-acetylcysteine in the presence of high concentrations of folic acid

A new vinylferrocene modified-multiwalled carbon nanotubes paste electrode was prepared and used for the determination of N-acetylcysteine (N-AC) and folic acid (FA). Using the modified electrode, a highly selective square wave voltammetric method for the simultaneous determination of N-AC and FA was developed. The peak currents of N-AC and FA increased linearly with their concentration in the ranges of 0.1-662 and 10.0-900 mu mol L-1, respectively, with corresponding detection limits of 0.09 and 7.0 mu mol L-1. The RSD% for 0.7 mu mol L-1 N-AC was 1.5%, whereas for 15.0 mu mol L-1 FA, it was 1.9%. Well separated oxidation peaks of N-AC and FA were obtained at pH 7.0 with this modified electrode. The modified electrode was successfully applied for the simultaneous determination of N-AC plus FA in real samples.