Ferrocene Modified Carbon Paste Electrode in Determination of Dopamin HCl using Differential Pulse Voltammetry Technique
Irdhawati, Gede Permana Rakasiwi, James Sibarani

Department of Chemistry, Faculty of Mathematic and Natural Science, Udayana University, Bukit Jimbaran Bali 80361 Indonesia.
E-mail: irdhawati[at]unud.ac.id

Abstract

The research about the detection of dopamine by differential pulse voltammetry technique using carbon paste electrode (CPE) modified by ferrocene (CPE- Fc) has been carried out. The purpose of this study was to determine the performance of the working electrodes and applied to determine the levels of dopamine HCl in commercial samples. The result obtained, pH optimum was found at 4.0, composition of ferrocene was 0.6% in carbon paste, and scan rate for CPE at 15 mV/s, increase to be 20 mV/s using CPE-Fc. The linier concentration range of CPE-Fc was at \( 20 - 800 \mu M \), wider than CPE at \( 50 - 300 \mu M \). The detection and quantification limits of CPE-Fc obtained at \( 0.0814 \mu M \) and \( 0.0825 \mu M \), which was smaller than EPK at \( 0.0885 \mu M \) and \( 0.0888 \mu M \), respectively. Repetition of measurements had Horwitz ratio values smaller than 2, for both of CPE and CPE-Fc. The percentage of recovery for dopamine HCl in the presence of sample solution as matrix was found at (89.92 \( \pm \) 0.81)% and (99.05 \( \pm \) 0.17)%, for sample A and B. The result of measurements of dopamine HCl in sample A and B were obtained 190.40 mg/mL and 38.64 mg/mL, with the conformity result of 95.20% and 96.62% with its labels. It can be concluded that the addition of ferrocene in carbon paste can improve the performance of working electrode.

Keywords: Carbon paste electrode, differential pulse voltammetry, dopamine HCl, ferrocene

Topic: Analytical Chemistry