Simultaneous and selective voltammetric determination of epinephrine, acetaminophen and folic acid at a ZrO2 nanoparticles modified carbon paste electrode

A new carbon paste electrode modified with ZrO2 nanoparticles (ZONMCPE) was prepared, and used to study the electrooxidation of epinephrine (EP), acetaminophen (AC), folic acid (FA) and their mixtures by electrochemical methods. The modified electrode displayed strong resolving function for the overlapping voltammetric responses of EP, AC and FA into three well-defined peaks. The potential differences between EP − AC, AC − FA and EP − FA were 210, 290 and 500 mV respectively. Differential pulse voltammetry (DPV) peak currents of EP, AC and FA increased linearly with their concentration at the ranges of 2.0 × 10−7–2.2 × 10−3 M, 1.0 × 10−6–2.5 × 10−3 M and 2.0 × 10−5–2.5 × 10−3 M, respectively. The detection limits for EP, AC and FA were found to be 9.5 × 10−8, 9.1 × 10−7and 9.8 × 10−6 M, respectively.