Electrochemical sensor based on a sepiolite clay nanoparticle-based electrochemical sensor for ascorbic acid detection in real-life samples

摘要

A new electrode composed of sepiolite clay (SC) carbon paste (CP) was developed and used for the adsorptive stripping differential pulse voltammetric quantification of ascorbic acid (AA). The effects of pH, the ratios of the electrode ingredients, accumulation potential, and accumulation time were investigated. The SC/CP electrode (SC/CPE) was found to have a good linear working range (1.4 x 10(-8)-9.0 x 10(-7) mol L-1) and the detection limit of 4.2 x 10(-9) mol L-1. The sensitivity is fairly good with LOQ of 0.014 mu mol L-1 and LOD of 0.0042 mu mol L-1. The selectivity in the presence of some common species, i.e., Na+, Cl-, Ca2+, Mg2+, NO3 (-) , citric acid, and glucose, at concentrations well above those encountered in body fluids was found to be satisfactory. The SC/CPE system has a lifetime not shorter than a month and proved to be practical for the analysis of not only pharmaceutical formulations but also natural products such as vitamin C-rich fruit Rosa canina and mineral waters.