Determination of Mercury Using a Novel Sonogel‐Carbon 3‐Methylthiophene Electrode

Abstract

A solid Sonogel-Carbon electrode was modified for the determination of Hg (II) in industrial waste water. 3-Methylthiophene (3MT), pyrrol, poly-3-methylthiophene (P3MT), polypyrrol, and C18 were used for the chemical modification. The obtained composite electrodes were tested for their response to Hg(II); the best results were observed for the 3MT monomer modification with a detection limit of 10 22 mg . l 21 and 3 weeks lifetime of use. A linear relationship between anodic peak height and concentration inside the range of 0.07 -0.42 mg . l 21 was obtained. A study of interferences due to other heavy metal is also included.

Electroanalytical applications of a graphite–Au nanoparticles composite included in a sonogel matrix

“…Several additional components, e.g. clays [9] or conducting polymers [10,11], can be added during the gelification phase, to introduce specific functionalities that improve the electroanalytical performances of the basic SNG/C material. However, by following the synthetic procedures reported so far, only a physical mixture of the additional component with graphite is obtained.…”

Electrode reactions and electroanalysis of organomercury compounds

“…Different anions 353 and cations (for example, see Refs 86,307,311,353,361 and 384) usually exerted no substantial effect on the electroanalytical determination of mercury; however, their presence could affect (see Table 4) the analytical signal and the ER potential, 353 especially if such cation [for example, Au(III)] formed intermetallic compounds with mercury. 349 The exception were the anions well adsorbed on the Hg electrode in the working potential range [Cl 7 , Br 7 , and especially I 7 (even in concentration >10 77 mol litre 71 ), 362 CNS 7 and several other 353,360 ], or coordinated with mercury. For example, the ER of the Hg 2+ cations in neutral non-coordinating media produced two VA peaks, whereas in the presence of even a weak complex-forming reagent such as the acetate ion (at pH 4.5), only one peak was observed.…”

“…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.…”

“…309)], which were prepared by deposition of the active metal on the backing (for instance, deposition of gold on carbon paste, 339 GC (Refs 88, 305) and iridium; 347 deposition of mercury on carbon, 85, 86 GC, 86 Pt, 83 gold 386 ), and also electrodes modified with various organic and inorganic additives. 298,338,345,346,353,383,395 Thus the electrode modification with polymers, resins and other reagents allowed extraction of the chloride ions thus preventing the adverse formation of calomel, which made easier the surface regeneration. 82,86,345 This procedure was especially efficient for electrodes prepared by screen printing 300,343,345,357,358 (particularly, carbon 343,345,357,358 as well as silver 300 ), which ensured high sensitivity and selectivity of detection.…”

Voltammetric Sensing of Mercury and Copper Cations at Poly(EDTA‐like) Film Modified Electrode

“…Use of CMEs furthermore greatly limits chemical interferences and allow sensing of metals as mercury or silver, which can not be analyzed with conventional mercury based anodic stripping voltammetry [28 -32]. Stripping voltammetric analyses of mercury have yet been reported at solid working electrodes using carbon paste incorporating various organic [33 -40] or inorganic compounds [41], sonogel carbon electrodes [42,43], glassy carbon electrodes in association with ion exchange resins [44,45], or with various electrolytes and additives [46 -48].…”