Experimental and statistical analysis on a nanostructured sensor for determination of p-hydroxybenzoic acid in cosmetics

Abstract

In this research, differential pulse voltammetry (DPV) coupled with experimental design, was used for de-termination ofp-hydroxybenzoic acid (PHB) in cosmetics. Optimization of effecting parameters was carried out based on rotatable central composite design (RCCD) and response surface methodology (RSM) at the surface of a nanostructured electrode for achieving the best sensitivity. Sol-gel process was used for synthesize of nickel titanate (NiTiO3) nanoceramics. The structural and morphological characterization of the nanoparticles was studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron mi-croscopy (SEM). Then the NiTiO3nanopowders were used for surface modification of a carbon paste modified electrode (CPE). Surface characterization of the electrode was accomplished using SEM, electrochemical im-pedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. Under the optimized conditions, the vol-tammograms exhibited two linear dynamic ranges of 0.7–80.0μM and 80.0–1000.0μM for PHB with the de-tection limit of 62.0 nM (S/N= 3). Finally the NiTiO3nanoceramics modified carbon paste electrode (NiTiO3/ CPE) could be employed for the determination of PHB in real samples with satisfactory results.