Application of NiO/CNTs nanocomposite ionic liquid paste electrode as avoltammetric sensor for determination of ascorbic acid in fruit juices samples

Ascorbic acid (AA), as a water soluble vitamin, is an effective reducing agent and a powerfulantioxidant in food, preventing color changes and alterations of aroma and flavor as well asextending the storage time of the products. So, determination of AA is very important in foodsamples [1]. In this study, a simple and rapid analytical method developed for ascorbic acid (AA)determination in fruit juices by using square wave voltammetry (SWV) method using NiO/CNTsnanocomposite ionic liquid modified carbon paste electrode as a sensor. Important parameterssuch as NiO/CNTs nanocomposite ratio, ionic liquid ratio and pH, have been optimized in thiswork. The cyclic voltammogram showed an irreversible oxidation peak at 0.4 V (vs. Ag/AgClsat),which corresponded to the oxidation of AA. Compared to common carbon paste electrode, theelectrochemical response was greatly improved. Under the optimized conditions, the oxidationpeak current of AA showed linear dynamic range 0.09–800.0 μ mol l−1 with a detection limit of0.05 μmol L-1, using the SWV method. The proposed sensor was successfully applied to thedetermination of AA in fruit juices without previous preparation and was compared with apublished electrochemical method

کلیدواژه ها:

Fruit juices analysis ، Ascorbic acid ، Voltammetry ، Ionic liquid NiO/CNTsnanocomposite