10.6084/M9.FIGSHARE.6007835.V1
Tayane A. Freitas
Manoel J. A. Lima
Aldaléa L. B. Marques
Edmar P. Marques
Rita C. S. Luz
Cicero W. B. Bezerra
Development of a Novel and Simple Electroanalytical Procedure for the Determination of Copper in Biofuel Employing a Sensor Based on Vulcan Functionalized with Carbazone
<div><p>A novel and simple electroanalytical method for the determination of Cu2+ in biodiesel samples by stripping voltammetric analysis was developed. The method employs a carbon paste electrode (CPE) modified with Vulcan carbon, previouly functionalized with carbazone (CBZ). The CPE/Vulcan-CBZ sensor promoted a significant increase in the analytical signal obtained from copper as compared to unmodified CPE, and the CPE modified with Vulcan carbon (CPE/ Vulcan). Vulcan-CBZ, Vulcan and CBZ materials were characterized by Fourier transform infrared spectroscopy (FTIR) technique. The electrochemical behavior of the sensor was evaluated using cyclic voltammetry (CV) and square-wave anodic stripping voltammetric (SWASV) techniques. The CPE/Vulcan-CBZ modified electrode showed excellent response and was able to detect Cu2+ at nanomolar levels. The electrochemical method is based on preconcentration of Cu2+ ions on the CPE/Vulcan-CBZ at 0.35 V vs. Ag/AgCl(sat) in 0.2 mol L-1 ammonium sulfate solution ((NH4)2SO4), pH 3.5, during 120 s, followed by subsequent chemical stripping. The analytical signal showed a linear response for Cu2+ concentrations in the range from 6 to 190 nmol L-1 (r = 0.998), with a detection limit of 1.2 nmol L-1. The sensor was successfully applied for the determination of Cu2+ in biodiesel and the average recovery varied between 97.0 and 102.8% for the soybean biodiesel samples and between 109.6 and 111.0% for the babassu biodiesel samples showing a good accuracy for the proposed method.</p></div>
30699 Physical Chemistry not elsewhere classified
SciELO journals
2018
2018-03-21
2018-03-21
Dataset
2546811 Bytes
10.21577/0103-5053.20170181
10.6084/m9.figshare.6007835
CC BY 4.0