Square wave voltammetric determination of ascorbic acid in food and pharmaceutical samples using a novel room temperature ionic liquid ZnO nanoparticles carbon paste electrode

Najafi, Maryam; Bijad, Majede; Lal Sanati, Afsaneh; Karimi, Fatemeh; Khalilzadeh, Mohammad Ali; Karimi-Maleh, Hassan

doi:10.22075/chem.2017.629

Square wave voltammetric determination of ascorbic acid in food and pharmaceutical samples using a novel room temperature ionic liquid ZnO nanoparticles carbon paste electrode

Authors

Maryam Najafi

Majede Bijad

Afsaneh Lal Sanati

Fatemeh Karimi

Mohammad Ali Khalilzadeh

Hassan Karimi-Maleh

10.22075/chem.2017.629

Abstract

In this paper we report synthesis and application of ZnO nanoparticle (ZnO/NPs) and 1, 3-dipropylimidazolium bromide as high sensitive sensors for voltammetric determination of ascorbic acid (AA) using carbon paste electrode. The ZnO/NPs was characterized with different methods such as TEM and XRD. The cyclic voltammogram showed an irreversible oxidation peak at 0.35 V (vs. Ag/AgClsat), which corresponded to the oxidation of AA. Compared to common carbon paste electrode, the electrochemical response was greatly improved. The electro-oxidation of AA occurred in a pH-dependent 2eâ and 2H+ process, and the electrode reaction followed a diffusion-controlled pathway. Under the optimum conditions, the voltammetric oxidation peak current of AA showed two linear dynamic ranges with a detection limit of 0.04 Î¼M for AA. The novel sensor has been found selective and successfully implemented for the determination of AA in fresh vegetable juice fruit juices, tablet and tablet samples without previous preparation and were compared with a published electrochemical method.

Keywords

Ascorbic acid, 1, 3-dipropylimidazolium bromide, ZnO nanoparticle

Carbon paste electrode