Is the boron-doped diamond electrode a suitable substitute for mercury in pesticide analyses? A comparative study of 4-nitrophenol quantification in pure and natural waters

Pedrosa, Valber A.; Codognoto, Lúcia; Machado, Sérgio Antônio Spínola; Avaca, Luís Alberto

doi:10.1016/s0022-0728(04)00330-4

Cited by 22 publications

(38 citation statements)

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“…Minor differences could be due to an internal resistance in the oxide layers while for DBB the reasons are mainly linked to the state of the surface prior to the experiment. 8 On the other hand, the quasi-reversible response recorded for the IrO 2 /BBD electrode ( Figure 2B) has been previously reported by Gottesfeld 39 who observed that the K 4 Fe(CN) 6 /K 3 Fe(CN) 6 redox couple in acid media showed a reversible behavior on an Ir rotating disk electrode that changed to irreversible when the electrode is covered by a Ir oxide layer, probably due to a blocking effect in the diffusion through the oxide film. Likewise, non-reversible behavior was observed for hydroquinone using an IrO x electrode while a reversible response was observed for gold in a borate buffer solution.…”

Section: Resultssupporting

confidence: 79%

“…It is well recognized that for a typical outer-sphere and diffusion-controlled reaction, as it is the case for the K 4 Fe(CN) 6 /K 3 Fe(CN) 6 redox couple in solution, the Randles-Sevick equation can be used: (1) where I p is the peak current, n is the electrons number, A is the active area of the electrode, D o is the diffusion coefficient, v is the scan rate and C o * is the bulk concentration of the specie. Then, a relation between I p and A can be established provided the reaction follows equation 1.…”

Section: Resultsmentioning

confidence: 98%

“…Thus, the voltammetric experiments shown in Figure 2 were recorded in 0.5 mol L -1 H 2 SO 4 + 10 -2 mol L -1 K 4 Fe(CN) 6 solutions except for that in the insert of Figure 2A that was carried out in the pure H 2 SO 4 solution. The insert presents a typical steady-state response of a polycrystalline Pt electrode in acid media.…”

Section: Resultsmentioning

confidence: 99%

“…The comparative cyclic voltammetries, aiming to determine the electrochemical active areas, were performed in a 1.0 x 10 -2 mol L -1 K 4 Fe(CN) 6 + 0.5 mol L -1 H 2 SO 4 solution while the OER studies were carried out in 0.5 mol L -1 H 2 SO 4 solution. The ethanol oxidation reaction was studied in a 0.5 mol L -1 CH 3 CH 2 OH + 0.5 mol L -1 H 2 SO 4 solution by cyclic and linear voltammetry and control potential electrolysis.…”

Section: Reagents and Apparatusmentioning

confidence: 99%

“…Boron-doped diamond (BDD) films have been largely used as electrode material in electroanalytical studies [1][2][3][4][5][6][7] since they posses an extraordinary chemical stability, low capacitive currents in an extended range of potentials and good reproducibility of the results if adequately pretreated. 8,9 Taking advantage of these qualities, several authors have also used BDD electrodes to study the oxidation or electrochemical combustion of organic 258 Suffredini et al J. Braz.…”

Section: Introductionmentioning

confidence: 99%

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AFM studies and electrochemical characterization of boron-doped diamond surfaces modified with metal oxides by the Sol-Gel method

Suffredini¹,

Salazar‐Banda²,

Okamura³

et al. 2006

J. Braz. Chem. Soc.

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Com o objetivo de aprofundar investigações anteriores, foram realizadas modificações superficiais diretas em eletrodos de diamante dopados com boro (DDB), com óxidos metálicos (PtO x , RuO 2 , IrO 2 e PbO 2 ) e com alguns compósitos mistos, utilizando a técnica Sol-Gel. Estes materiais foram estudados por microscopia de força atômica (MFA) e os resultados indicaram a formação de sítios de deposição heterogênea. Técnicas eletroquímicas foram utilizadas para estabelecer a atividade catalítica para a reação de desprendimento de oxigênio (RDO) e para reação de oxidação de etanol em meio ácido utilizando os compósitos de PtO x e PtO x -RuO 2 . Testou-se ainda a estabilidade de um depósito de PtO x , recoberto por um filme de Nafion ® , por meio de operação contínua de longa duração. Estudos de voltametria cíclica comparativa mostraram que a área superficial ativa dos novos materiais mudou consideravelmente com o método de modificação proposto. O eletrodo de IrO 2 /BDD mostrou o melhor desempenho para a RDO, iniciando o processo de oxidação em ~ 1.4 V vs. HESS, valor este 200 mV menor do que o observado sobre um eletrodo de PtO x /BDD. Foi observada uma pequena perda da atividade do eletrodo de PtO x /BDD (6%) depois de realizada eletrólise de 4 horas, enquanto que 1000 ciclos voltamétricos deixaram a superfície praticamente inalterada. Os estudos realizados mostram que as atividades satisfatórias dos eletrodos preparados pelo método Sol-Gel podem constituir ferramentas interessantes de pesquisa, visando principalmente a utilização destes materiais em aplicações práticas.Continuing previous investigations, direct surface modifications of boron-doped diamond (BDD) electrodes with metal oxides (PtO x , RuO 2 , IrO 2 and PbO 2 ) and with some mixed composites were carried out by the Sol-Gel technique. The materials were studied by atomic force microscopy (AFM) to determine their surface topologies and by electrochemical techniques to establish the catalytic activity towards the oxygen evolution reaction (OER) and also, for the PtO x and PtO xRuO 2 composites, the ethanol oxidation reactions in acid media. The stability of PtO x coating covered by a Nafion ® film was also tested by long-term operation. The AFM results indicated sites of heterogeneous deposition and the electrochemical studies demonstrated that the active surface area changed considerably with the proposed method of modification. The IrO 2 /BDD electrode showed the best performance to the OER with the onset of the oxidation current at ~1.4 V, a value 200 mV lower than for the PtO x /BDD electrode. The enhanced stability of PtO x /BDD electrodes achieved by the application of a Nafion ® film and already reported in acid media was further proved using the ethanol oxidation reaction. Only a small loss of activity (6%) was observed after 4-hours electrolysis while one-thousand voltammetric cycles left the surface practically unchanged. In addition, preliminary studies for the same reaction on PtO x /BDD and PtO x -RuO 2 / BDD electrodes demonstrated the excell...

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Section: Resultssupporting

confidence: 79%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Reagents and Apparatusmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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AFM studies and electrochemical characterization of boron-doped diamond surfaces modified with metal oxides by the Sol-Gel method

Suffredini¹,

Salazar‐Banda²,

Okamura³

et al. 2006

J. Braz. Chem. Soc.

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Study of the Electrochemical Behavior and Sensitive Detection of Pesticides Using Microelectrodes Allied to Square-Wave Voltammetry

Souza

Machado

2006

Electroanalysis

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This work describes the application of gold and carbon fiber microelectrodes allied to square-wave voltammetry for the study of the electrochemical behavior of the organophosphorous insecticides (methyl parathion and dichlorvos) and bipyridilium herbicides (paraquat and diquat), and the development of the sensitive methodology for their analytical determinations in natural water samples. The microelectrodes were lab-made constructed and their electrochemical behavior was characterized by measuring the electrochemical response with a solution of potassium ferricyanide. The experimental and voltammetric conditions to obtain the best analytical signal, in terms of intensities and profile of the peak voltammetric, for four pesticides were optimized and the results were used to evaluate the type of the electrochemical redox process and to appraise the number of electrons covered in each reduction process that occurred for pesticides and also, to propose a possible redox mechanism for a reduction process of pesticides at microelectrodes. Analytical curves were constructed and presented the linear relationships between the peak currents and the concentration of pesticides, for this, the detection limits for pure water (laboratory samples) for four pesticides were calculated and presented values under 15 mg L À1 , lower than maximum limit for drinking water (100 mg L À1 ) permitted by Brazilian Council for groundwater, indicating that the methodology could be employed to analyze those pesticides in natural water samples.

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Nontraditional Electrode Materials in Environmental Analysis of Biologically Active Organic Compounds

et al. 2007

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This review describes recent results regarding voltammetric and amperometric determination of submicromolar concentrations of various environmentally important biologically active organic substances using nontraditional types of electrodes either in batch analysis or in flow liquid systems (especially HPLC or FIA with electrochemical detection). Attention is paid to solid amalgam electrodes (environmentally friendly alternatives to mercury electrodes), to carbon paste electrodes with easily renewable surface, to boron doped diamond film electrodes with very low noise and broad potential window, and to inexpensive solid composite electrodes with high signal-to-noise ratio, compatibility with organic solvents and easy mechanical or electrochemical pretreatment. The review concentrates on our own results in the context of the general development in the filed.

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Is the boron-doped diamond electrode a suitable substitute for mercury in pesticide analyses? A comparative study of 4-nitrophenol quantification in pure and natural waters

Cited by 22 publications

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AFM studies and electrochemical characterization of boron-doped diamond surfaces modified with metal oxides by the Sol-Gel method

AFM studies and electrochemical characterization of boron-doped diamond surfaces modified with metal oxides by the Sol-Gel method

Study of the Electrochemical Behavior and Sensitive Detection of Pesticides Using Microelectrodes Allied to Square-Wave Voltammetry

Nontraditional Electrode Materials in Environmental Analysis of Biologically Active Organic Compounds

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