Optimisation of mercury film deposition on glassy carbon electrodes: evaluation of the combined effects of pH, thiocyanate ion and deposition potential

Monterroso, Sandra C. C.; Carapuça, Helena M.; Simão, João E.J.; Duarte, Armando C.

doi:10.1016/j.aca.2003.10.034

Cited by 43 publications

(25 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…35,36 This electrode offers a large surface area to volume ratio that provides a higher amalgam concentration during the deposition step, resulting in higher plating efficiency. In addition, the diffusion from the bulk of the film to the surface is very fast resulting in superior sensitivity and selectivity.…”

Section: Methodsmentioning

confidence: 99%

Simultaneous monitoring of toxic metals on white poplar (populus) by SWASV

Silva¹,

Lopes²,

Leitão³

et al. 2005

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

foi utilizada na determinação simultânea de quantidades traço dos metais tóxicos Pb(II), Cd(II) e Cu(II) em folhas de choupo (populus), utilizadas como bio-indicador, recolhidas numa área de tráfego automóvel intenso da cidade de Lisboa. As folhas, após secagem, foram submetidas a um processo de digestão ácida por microondas. Para a aplicação desta técnica à análise das folhas foi realizado um estudo de optimização dos vários parâmetros voltamétricos. O eletrodo de trabalho consistiu num filme de mercúrio depositado numa superfície de carbono vítreo. O sistema Ag/AgCl foi utilizado como referência e um fio de Platina como eletrodo auxiliar. Concentrações médias (em mg de metal/kg de matéria seca -folhas) de 2,6, 0,18 e 5,0 foram obtidas para o Pb(II), o Cd(II) e o Cu(II), respectivamente. O valor obtido para o chumbo coincide com o obtido pelo método de referência baseado na Espectrofotometria de Absorção Atômica em Forno de Grafite (EAAFG).Square wave anodic stripping voltammetry (SWASV) was applied to the simultaneous determination of trace amounts of toxic metals Pb(II), Cd(II) and Cu(II) in white poplar (populus) leaves, used as bio indicator and gathered in a chosen area of the city of Lisbon with very high traffic intensity. The leaves were dried and subsequently exposed to an acid digestion microwave process. Square wave parameters were optimized for the voltammetric analysis of the samples. The working electrode consisted of a thin mercury film (TMFE) deposited on the surface of vitreous carbon. The pair Ag/AgCl was used as the reference electrode and a Pt wire as the auxiliary electrode. Average concentrations (in mg of metal/kg of dry matter-leaves) of 2.6, 0.18, and 5.0 were obtained for Pb(II), Cd(II) and Cu(II), respectively. The value for lead coincides with the one obtained by the reference method based on Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS).

show abstract

Section: Methodsmentioning

confidence: 99%

Simultaneous monitoring of toxic metals on white poplar (populus) by SWASV

Silva¹,

Lopes²,

Leitão³

et al. 2005

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Electrodeposition of mercury onto glassy carbon in acidic solutions of thiocyanate, provides highly homogeneous and reproducible mercury films of nanometer thickness [17]. In the present work, the performance of this type of TMFE, ex situ prepared in thiocyanate media, was evaluated in order to assess their potential application for SCP/ SSCP experiments.…”

Section: Evaluation Of the Stability And Durability Of Thin Mercury Fmentioning

confidence: 99%

“…The charge associated to the deposited mercury (Q Hg ) was calculated by electronic integration of the linear sweep stripping peak of mercury, for v = 0.005 V s À1 . The electrolyte solution was ammonium thiocyanate 5 mM (pH 3.4) [17]. The stripping step began at À0.15 V and ended at +0.6 V [20].…”

Section: Preparation Of the Thin Mercury Film Electrodementioning

confidence: 99%

“…The thin mercury film was than ex situ prepared in 0.03-0.12 mM mercury (II) nitrate in thiocyanate media (5 mM, pH 3.4) by electrodeposition at À1.3 V for different deposition times (180, 240 or 360 s) and a rotation rate of 1000 rpm [17,18]. The charge associated to the deposited mercury (Q Hg ) was calculated by electronic integration of the linear sweep stripping peak of mercury, for v = 0.005 V s À1 .…”

Section: Preparation Of the Thin Mercury Film Electrodementioning

confidence: 99%

“…Stable TMFE could be easily plated (ex situ or in situ mode), by a single electrodeposition step of high overpotential, in acidic solutions containing thiocyanate anion. In these conditions homogeneous and stable mercury deposits of high reproducibility could be prepared [17].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Evaluation of nanometer thick mercury film electrodes for stripping chronopotentiometry

Rocha

Pinheiro

Carapuça

2007

Journal of Electroanalytical Chemistry

View full text Add to dashboard Cite

In this work, the performance and applicability of the thin mercury film electrode (TMFE) in the heavy metal speciation, by stripping chronopotentiometry (SCP), were exploited. The TMFE thickness was optimized and a 7.6 nm mercury film was selected. This TMFE was mechanically stable and able to perform 60 SCP consecutive measurements, with no significant variation in the analytical signal of lead(II) (RSD less than 2%). Due to the small electrode thickness the measurements were performed under conditions of complete depletion over a wide oxidation current (I s ) range, i.e., within the interval [75-500] · 10 À9 A. The limit of detection (3r) for lead(II) was 2.4 · 10 À9 M for a deposition time of 40 s and an oxidation current of 75 · 10 À9 A. The TMFE was successfully applied to the construction of SSCP experimental waves, which were in conformity to those predicted by the theory. The stability constant calculated (K 0 ) for the Pb(II)-carboxylated latex nanospheres system using a TMFE, agreed with the one obtained using the HMDE, for identical experimental conditions.

show abstract

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

2006

View full text Add to dashboard Cite

An attempt is made to describe the electrochemical properties of bismuth films, plated in-situ on glassy carbon in acetic buffer, over a broad range of deposition potentials. It is shown that accumulation during anodic stripping voltammetric determination of lead and zinc at the bismuth film electrode depends to a large extent on the electrolyte composition and the plating parameters. The influence of the plating potential on Pb deposition is moderate, but it could not be disregarded during Zn quantification. The sources of electrode poisoning effects are discussed in detail. Voltammetric studies are complemented by AFM microscopic observations.

show abstract

Optimisation of mercury film deposition on glassy carbon electrodes: evaluation of the combined effects of pH, thiocyanate ion and deposition potential

Cited by 43 publications

References 27 publications

Simultaneous monitoring of toxic metals on white poplar (populus) by SWASV

Simultaneous monitoring of toxic metals on white poplar (populus) by SWASV

Evaluation of nanometer thick mercury film electrodes for stripping chronopotentiometry

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

Contact Info

Product

Resources

About