Voltammetric detection of arsenic on a bismuth modified exfoliated graphite electrode

Ndlovu, Thabile; Mamba, Bhekie B.; Sampath, S.; Krause, Rui W. M.; Arotiba, Omotayo A.

doi:10.1016/j.electacta.2013.08.084

Cited by 78 publications

(38 citation statements)

References 31 publications

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“…pattern is obtained for these modified CPEs ( Figure S1), however, the anodic/cathodic peak current is proportional to the scan rate. Moreover, the scan rate studies are also commensurate with the electroactive surface area of the modified CPEs [32]. Therefore, the mass transfer study using the hybrid material modified carbon paste electrode was performed ( Figure 5).…”

Section: Electrochemical Response Of Modified Cpementioning

confidence: 99%

Efficient Use of Porous Hybrid Materials in a Selective Detection of Lead(II) from Aqueous Solutions: An Electrochemical Study

Zirlianngura

Tiwari

et al. 2017

Metals

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Due to health and pollution concerns of aquatic environments related to the presence of heavy metal toxic ions, the necessity of developing devices able to detect and to monitor such kinds of species has recently gained importance. Carbon paste electrodes (CPEs) a starting approach to obtain new ion-selective devices by supporting materials like bentonite and/or clay; which become sensitive to lead(II) when they are suitably modified by chemical treatments to obtain different hybrid materials. In this work, two natural clays and three different hybrid materials were produced and then were characterized by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy to assess their physico-chemical properties. After this stage, the electrochemical characterization of the modified CPEs using hybrid materials was performed by cyclic voltammetry, using the standard Fe(CN) 6 4− /Fe(CN) 6 3− redox couple. Subsequently, this study performed electrochemical experiments on lead(II) containing solutions, to test the ability of the examined CPEs to detect this toxic ion present in very low amounts. Lead(II) exhibited a reversible two electron oxidation/reduction behaviour in the cyclic voltammetry analyses and a reasonably good linear behaviour of the current associated with the oxidation peak as a function of its concentration (5.0-40.0 µg/L). The detection limit was found to vary in the range of 3-5 µg/L for the different modified CPEs. The presence of several co-existing ions showed that an interference variation had occurred. These results, therefore, show a restriction of the selectivity of the electrode up to a certain extent in the lead(II) detection. Finally, tap water with spiked lead(II) was analyzed to verify the suitability of the electrodes in the low level detection of lead(II) from real matrix samples.

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Section: Electrochemical Response Of Modified Cpementioning

confidence: 99%

Efficient Use of Porous Hybrid Materials in a Selective Detection of Lead(II) from Aqueous Solutions: An Electrochemical Study

Zirlianngura

Tiwari

et al. 2017

Metals

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“…The linear ranges were 30–500 μM for phenylarsonic acid and 2–500 μM for arsenate. The LODs of both species are comparable with those from electrochemical methods and from sensors based on gold nanoparticles . The LOD for arsenate (As(V)) is also sufficient to meet the World Health Organization's guideline value of 10 µg L −1 elementary arsenic .…”

Section: Resultsmentioning

confidence: 83%

Hyphenation of capillary high‐performance ion‐exchange chromatography with mass spectrometry using sheath‐flow electrospray ionization

Kochmann

Matysik

2014

Rapid Comm Mass Spectrometry

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RATIONALE: Mass spectrometry (MS) is an attractive method for extending capillary-size ion chromatography (cHPIC) to create a valuable technique for speciation analysis. For hyphenation, the aqueous effluent of cHPIC has to be transformed into a volatile mixture for MS while preserving analytical concentrations as well as peak shapes during transfer from cHPIC to MS. Finally, the approach should technically be flexible and easy-to-use. A combination of cHPIC and sheath-flow electrospray ionization (ESI)-MS offers to solve all these challenges. METHODS: cHPIC/sheath-flow-ESI-TOFMS was used in this study for the speciation analysis of various arsenic model compounds. These model compounds were analyzed with different hyphenation setups and configurations of cHPIC/MS and their respective assets and drawbacks were examined and discussed. The parameters (flow rate and composition of sheath liquid) of sheath-flow ESI and their influence on the performance of the spray and the sensitivity of the detector were investigated and compared with those of sheathless ESI. RESULTS: Using an injection valve to couple cHPIC and MS was found to be the best method for hyphenation, since it constitutes a flexible and dead-volume-free approach. The investigation of sheath-flow ESI revealed that the flow rate of the sheath liquid has to resemble the flow rate of the IC effluent to ensure a stable spray and that a composition of 2-propanol/water/ammonia at 50:50:0.2 (v/v/v) suits most applications without unilaterally promoting the sensitivity for either organic or inorganic compounds. The optimized setup and conditions were successfully applied to the analysis of a mixture of important arsenic species and used to determine limits of detection of organic and inorganic arsenic species (3.7 μg L À1 elemental arsenic). CONCLUSIONS: A method for cHPIC/sheath-flow-ESI-MS was developed. The method was shown to be a valuable tool for speciation and trace analysis. It features no dead volume, fast transfer from IC to MS, only minimal peak-widening, high reproducibility, and the ability to fine-tune the ESI spray for higher sensitivity and stability by adjusting the composition of the sheath-liquid.

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“…(5) The analysis can be simplified by: the replacement of precious metal electrodes by inexpensive materials [44,47,33,60,[99][100][101][102][103][104]; analysis without removing oxygen from solution [38,55,75,91]; minimizing the sample preparation stage by eliminating the reduction of As(V) to As(III), and speciation of As in the field. Automation of procedures is helpful and there has been some research aimed at creating microfluidic total analysis systems which would be ideal for this purpose [4].…”

Section: As(iii) Determination By Anodic Stripping Voltammetry (Asv)mentioning

confidence: 99%

Inorganic arsenic speciation by electroanalysis. From laboratory to field conditions: A mini-review

Antonova

Захарова

2016

Electrochemistry Communications

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Voltammetric detection of arsenic on a bismuth modified exfoliated graphite electrode

Cited by 78 publications

References 31 publications

Efficient Use of Porous Hybrid Materials in a Selective Detection of Lead(II) from Aqueous Solutions: An Electrochemical Study

Efficient Use of Porous Hybrid Materials in a Selective Detection of Lead(II) from Aqueous Solutions: An Electrochemical Study

Hyphenation of capillary high‐performance ion‐exchange chromatography with mass spectrometry using sheath‐flow electrospray ionization

Inorganic arsenic speciation by electroanalysis. From laboratory to field conditions: A mini-review

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