Determination of Mercury by Chronopotentiometric Stripping Analysis Using Glassy Carbon Vessel as a Working Electrode

Abstract

In this work chronopotentiometric stripping analysis of mercury was performed using a process vessel of glassy carbon as a working electrode. Experimental parameters for both steady and rotating vessel were investigated and compared. Relative sensitivity as well as the sharpness of the analytical signal was better when the rotation of the process vessel was performed. The new design provided better sensitivity when compared to both stationary and rotating glassy carbon disk electrodes. Detection limit obtained for the electrolysis time of 600 s was 0.1 ng/L of Hg(II). The accuracy of the technique was confirmed by analyzing the standard reference material -tomato leaves.

Electrode reactions and electroanalysis of organomercury compounds

“…323 ± 396 Considering electrochemical methods as such, the most popular methods are different kinds of voltammetry (first of all, cathodic and anodic stripping voltammetry, 340,349,360,361,379 cyclic voltammetry, 78 ± 86, 301 rotating disk electrode 81, 320 ), reverse chronopotentiometry or coulometry with preconcentration. 314,315 In recent years, in addition to the mentioned methods, the methods of electrochemiluminescence, 375 electrochemical impedance 353,354,376 and also of stripping voltammetry coupled with surface plasmon resonance and with magnetohydrodynamic convection 374 were used. According to certain data, 295 the method of cold vapour atomic absorption spectroscopy may prove to be more convenient than voltammetry in the analysis of biological objects, because it requires no timeconsuming pre-treatment of samples before the analysis.…”

“…387 For this purpose, when using the electrode containing gold nanoparticles deposited on GC, 88 it was recommended to bind mercury into complexes with ethylenediaminetetraacetic acid, in the similar manner as in bioelectrochemical studies of oligodeoxynucleotides in the presence of Hg(II). 389 Moreover, in the electroanalytical practice, platinum 86,320,336,337,350 and different forms of carbon, namely, carbon paste, 310,311,327,342,356,364,365,390 fibres, 85,86,349 porous carbon, 391 GC, 81,86,314,340,344,370 graphite, 351 doped diamond 352,371,392 are widely used. Carbon materials of such a kind including also pyrolytic graphite and carbon nanotubes were considered 339, 383 as the most convenient supports for mercury film electrodes.…”