In-situ Modified Antimony-Film Glassy Carbon Electrode for Metal Trace Analysis

Abstract

Glassy carbon electrodes (GCE) have been extensively employed for the determination of trace amounts of heavy metals. Lately, modifications of GCE are currently being sought. One way of obtaining better analytical performance compared to GCE is the employment of an in situ prepared antimony-film glassy carbon electrode (SbFE). This combination is especially attractive in anodic stripping voltammetry technique which uses square wave excitation signal. This work will report on the optimization of the in situ prepared SbFE by employing different deposition potentials. Furthermore, a preliminary study using electrochemical impedance spectroscopy (EIS) was performed at different deposition and measured potentials in order to understand the mechanism of SbFE sensor performance.

A Comparison of Hydrochloric Acid and Acetate Buffer Media for Trace Metal Analysis Using Sb-Film Electrodes: A Detailed Electrochemical Impedance Spectroscopy Study

“…The deposition of Sb and the analytes for partial method validation was performed at -1.1 V in the case of the 0.01 M HCl solution and at -1.4 V for the acetate buffer solution, with an accumulation time (t acc ) of 60 s in both cases. The accumulation potential for the 0.01 M HCl solution was selected based on our previous study, which revealed the best electroanalytical performance when accumulation potential optimization was performed at -1.0, -1.1, and -1.2 V. 34 An accumulation potential of -1.4 V was selected based on the voltammograms measured (presented below), where hydrogen evolution was not intensive at that accumulation potential and the three analytes were accumulated on the electrode surface from the 0.1 M acetate buffer solution with and without the addition of 0.5 mg/L Sb(III). The cleaning and deposition steps were performed under continuous stirring (300 rpm).…”

Recent advances in the modification of electrodes for trace metal analysis: a review

“…197,248 Trace heavy metal analysis has been performed either with just BiFEs 247,248,252,253,[255][256][257]260 or with electrodes modified with a Bi-film combined with other materials and/or compounds, including with different NMs, 25,50,83,181,256 Nafion and GO, 40,83,233,235,250 as well as doping of the Bi-films with boron or indium. 245,259 Various other metals, including Sb, [261][262][263][264] Cu, [265][266][267] Au, 268 Pb, 269 and Hg, 260 have also been electrodeposited on different types of electrodes. Moreover, complexing agents such as 8-hydroxyquinoline, 251 nioxime, 265 and cupferron 269 have been added during the in situ Bi-, Pb-, and Cu-film modification of GCEs.…”

“…7,12,243 In the last five years, the research was focused on preparing two main types of film electrodes, i.e. , metallic- 25,40,50,83,181,197,233,235,245–273 and polymeric-film electrodes. 77,91,94,95,141,210,217,220,223–230,274–276 However, the combination of metallic (Bi) and polymer films ( i.e.…”