Evaluations of solid electrodes for use in voltammetric monitoring of heavy metals in samples from metallurgical nickel industry

Abstract

Evaluation of different solid electrode systems for detection of zinc, lead, cobalt, and nickel in process water from metallurgical nickel industry with use of differential pulse stripping voltammetry has been performed. Zinc was detected by differential pulse anodic stripping voltammetry (DPASV) on a dental amalgam electrode as intermetallic Ni-Zn compound after dilution in ammonium buffer solution. The intermetallic compound was observed at -375 mV, and a linear response was found in the range 0.2-1.2 mg L(-1) (r(2)=0.98) for 60 s deposition time. Simultaneous detection of nickel and cobalt in the low microg L(-1) range was successfully performed by use of adsorptive cathodic stripping voltammetry (AdCSV) of dimethylglyoxime complexes on a silver-bismuth alloy electrode, and a good correlation was found with corresponding AAS results (r(2)=0.999 for nickel and 0.965 for cobalt). Analyses of lead in the microg L(-1) range in nickel-plating solution were performed with good sensitivity and stability by DPASV, using a working electrode of silver together with a glassy carbon counter electrode in samples diluted 1:3 with distilled water and acidified with H(2)SO(4) to pH 2. A new commercial automatic at-line system was tested, and the results were found to be in agreement with an older mercury drop system. The stability of the solid electrode systems was found to be from one to several days without any maintenance needed.

Effects of Electroplating Variables on the Voltammetric Properties of Bismuth Deposits Plated Potentiostatically

“…To overcome these disadvantages less toxic mercury-containing materials have been used such as dental amalgams [2,3]. In the literature one could find a great amount of electrode materials with performance more or less similar to that of mercury [4]. An especially promising substitute for mercury is bismuth.…”

Voltammetric procedure for trace metal analysis in polluted natural waters using homemade bare gold-disk microelectrodes

“…Another attempt with Ir microelectrodes with only traces of mercury was successful for Pb and Cd determination and measurements in box-core sediments [16]. Preparation for in-field measurements has been carried out on gold electrodes in acidic solutions [17,18], solid dental amalgam electrodes [19,20] and alloys [21]. KirowaEisner's team [22][23][24][25][26][27] researched solid bare silver and gold electrodes of macro scale, contributing to a better understanding and application of underpotential deposition (UPD) effects in stripping voltammetry [28].…”

Pyrolyzed Photoresist Carbon Electrodes for Trace Electroanalysis of Nickel(II)

“…Compared to other "environmental-friendly" electrode materials, such as silver [16], iridium [17], several alloys [18] and different configurations of carbon [19], bismuth displays better electroanalytical performance and, therefore, has been commonly accepted as a replacement for mercury.…”