Modulated polarographic and voltammetric techniques in the study of natural water chemistry

Davison, William; Whitfield, M.

doi:10.1016/s0022-0728(77)80215-5

Cited by 67 publications

(14 citation statements)

References 95 publications

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“…Under the assumption that Madison tap water is not unique, a great deal of method development and selection of analysis conditions appears to be necessary before ASVWC results can be confidently related to either the total metal ion concentration or its activity. This conclusion is in line with a recent review and evaluation of ASV (6).…”

Section: Discussionsupporting

confidence: 91%

“…This work indicates that in native (pH 7.1) or acidified (pH 5.0-5.7) tap water, a significant fraction of the cupric ion is complexed or otherwise bound, and that ASVWC measures not just the free copper ion but also at least a fraction of the bound. These conclusions are not at variance with those of other workers who have investigated ASV (6).…”

Section: (Activity)contrasting

confidence: 53%

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Anodic stripping voltammetry with collection at tubular electrodes for the analysis of tap water

Schieffer¹,

Blaedel²

1978

Anal. Chem.

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Portable, battery operated equipment is described, tested, and characterized for the performance of anodic stripping voltammetry with collection (ASVWC) at two mercury-coated glassy carbon tubular electrodes in series. By operating the collection electrode at a constant cathodic potential, charging current background6 are reduced greatly, permitting better perceptlon of peak currents than with conventional ASV. The equipment is applied to the analysis for Cd, Pb, and Cu in tap water at subnanomolar levels.Anodic stripping voltammetry with collection is a technique t h a t was invented for the rotated ring-disk electrode, but which may be performed a t two tubular electrodes in series on a flowing stream. Trace metal cations are deposited on the upstream electrode from the flowing sample solution, stripping from that electrode with an anodic potential scan, and are collected by deposition on the downstream electrode, which is held at a constant cathodic deposition potential. The constant potential applied to the collection (analytical) electrode eliminates the charging current normally encountered with conventional anodic stripping voltammetry (ASV).In a previous paper ( I ) we reported the theoretical and experimental dependences of stripping and collection peaks on flow rate, deposition time, scan rate, and concentration observed with a twin tubular electrode designed for ASVWC.T h e potential of the stripping electrode was controlled with a commercial two-electrode polarograph, while the potential of the collection electrode was held constant with a battery voltage source and a ten-turn precision potentiometer. This simple setup enabled data of sufficient quality to be accumulated to characterize the cell, support the theory, and to indicate the inherent sensitivity of the method. Based on the earlier theoretical treatment, and the need for on-site probes suitable for rapid analysis of environmental samples, we have designed and built battery operated dual potentiostat equipment and a flow-through electrolysis cell that have the capability for on-site analysis. The equipment is characterized and applied to the analysis of a tap water sample. E X P E R I M E N T A L Apparatus. The cell design was similar to that described previously ( I ) except that a platinum wire counter electrode was inserted into the tubular channel downstream from the reference electrode bridge, which consisted of cation-exchange membrane washers. The stripping and collection electrodes were of the same area (0.067 cm2) and were separated by a 0.011-inch Teflon spacer. (A cell in which the stripping electrode area was three times that of the collection electrode was also constructed. However, exploratory results indicated only a slight increase in sensitivity over the previous version, but with a significant increase in peak broadening and loss of resolution. As a result, this cell was not studied further.)The dual potentiostat for simultaneously and independently controlling the potential of both working electrodes was similar Present add...

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Section: Discussionsupporting

confidence: 91%

Section: (Activity)contrasting

confidence: 53%

Anodic stripping voltammetry with collection at tubular electrodes for the analysis of tap water

Schieffer¹,

Blaedel²

1978

Anal. Chem.

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“…The VIP system [13], which uses a Iridium -Hg electrode and is commercially available, has been used to measure Fe(II) in Lake waters similarly at the mmol L À1 level. Early studies by Davison [14,15] and coworkers utilized pulse polarography for Fe(II) with a hanging mercury drop or dropping mercury electrodes.…”

Section: Introductionmentioning

confidence: 99%

Determination of Labile Iron at Low nmol L⁻¹ Levels in Estuarine and Coastal Waters by Anodic Stripping Voltammetry

2006

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A new method is presented for the determination of electrochemically labile iron in estuarine and coastal seawater. The method is based on differential pulse anodic stripping voltammetry (DPASV) at a rotating silver-alloy disk electrode. The voltammetric parameters include a plating potential of À 1.5 V and an activation potential of À 5 V for 10s; the seawater is at the original sample pH. The main finding is the presence of a peak for low nmol L À1 levels of iron at À 0.55 V ascribed to elemental iron deposited on the bare silver alloy electrode. The peak increased linearly with the iron concentration between < 1 and 14 nmol L À1 using a 900 s plating time. At higher concentrations an additional iron peak appeared at À 0.7 V which was also found to increase linearly with the iron concentration but at a higher concentration range from ca. 15 to 90 nmol L À1 using a 300 s plating time. The second peak was ascribed to iron deposited on iron. Additions of chelating agents (EDTA and a siderophore) to seawater caused the iron peak to be masked indicating that this method is suitable for iron speciation as only the electrochemically labile fraction is determined. The detection limit was 0.3 nmol L À1 using a 900 s plating time. The method was used to determine iron in the range of 5 to 50 nmol L À1 in samples from the Mersey estuary near Liverpool and its potential use for in situ monitoring was demonstrated by using it to monitor labile iron (at 2 -3 nmol L À1) over a period of 4 days at 1 h intervals in coastal waters in the Trondheim fjord, Norway.

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“…[4]. Direct measurement of surfactants by electrochemical methods has proved useful in the determination and characterization of organic matter in natural and polluted waters [5,6]. The height of tensammetric peaks can be used for quantitative analytical purposes.…”

Section: Introductionmentioning

confidence: 99%

Tensammetric Analysis of Nonionic Surfactant Mixtures by Artificial Neural Network

2005

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An artificial neural network (ANN) model has been developed for tensammetric determination of a series of Brijes (Brij 30, Brij 35, Brij 56, Brij 96) as nonionic surfactants. The tensammetric method is based on the measurement of the capacitive current of the mercury electrode after adsorption of surfactants. All Brijes were analyzed in the concentration range of 1.0 -100.0 mg mL À1. The proposed method shows good sensitivity and applicability to the simultaneous determination of mixtures of four Brijes in aqueous solutions.

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Modulated polarographic and voltammetric techniques in the study of natural water chemistry

Cited by 67 publications

References 95 publications

Anodic stripping voltammetry with collection at tubular electrodes for the analysis of tap water

Anodic stripping voltammetry with collection at tubular electrodes for the analysis of tap water

Determination of Labile Iron at Low nmol L⁻¹ Levels in Estuarine and Coastal Waters by Anodic Stripping Voltammetry

Tensammetric Analysis of Nonionic Surfactant Mixtures by Artificial Neural Network

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Modulated polarographic and voltammetric techniques in the study of natural water chemistry

Cited by 67 publications

References 95 publications

Anodic stripping voltammetry with collection at tubular electrodes for the analysis of tap water

Anodic stripping voltammetry with collection at tubular electrodes for the analysis of tap water

Determination of Labile Iron at Low nmol L−1 Levels in Estuarine and Coastal Waters by Anodic Stripping Voltammetry

Tensammetric Analysis of Nonionic Surfactant Mixtures by Artificial Neural Network

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Determination of Labile Iron at Low nmol L⁻¹ Levels in Estuarine and Coastal Waters by Anodic Stripping Voltammetry