Anodic stripping voltammetry procedure

SHUMAN M.S. and CROMER J.L. 1979. Copper association with aquatic fulvic and humic acids. Estimation of conditional formation constants with a titrimetric anodic stripping voltammetry procedure. Environmental Science and Technology, 13, 543-545. 

Stripping voltammetry procedure has been developed for determination of thallium(I) traces in aqueous medium on a mercury film electrode with application of thallium preconcentration by coprecipitation with manganese (IV) hydroxide. More than 90% of thallium present in water sample is uptaken by a deposit depending on conditions of prepai ation of precipitant. Direct determination of thallium was carried out by stripping voltammetry in AC mode with anodic polarization of potential in 0,06 M ascorbic acid in presence of 5T0 M of mercury(II) on PU-1 polarograph. 

We shall now consider the electrochemical apparatus used (electrodes and electrolytic cell) and the three steps in its procedure more closely, especially for anodic stripping voltammetry (ASV) as most important application. 

Stripping analysis with inherent pre-concentration seems attractive to CFA, but until recently such a procedure appeared rather exceptional. It has been used in the automatic determination of heavy metals in water by anodic stripping voltammetry (ASV12S) in a continuous flow cell with a mercury-covered graphite electrode, having the advantage that one can distinguish... 

A practical application of BCFMEs is the determination of gold by anodic stripping voltammetry [124], In this work, the BCFMEs were employed for the determination of tetrachloroaurate(III) complex in spiked samples of tap water. The methodology proposed is very easy and the details can be found in Procedure 46 in CD accompanying this book. 

Figure 14.7 shows the technique of anodic stripping voltammetry with collection at a double hydrodynamic electrode30. The fact that it is possible to control the potentials of generator and detector electrodes independently is used to increase sensitivity. This procedure has been used with success at rotating and wall-jet electrodes4,27... 

Anodic stripping voltammetry — Refers to a family of procedures involving a - preconcentration by electrochemical reduction of the - analyte (or a salt or derivative of the analyte) onto (or into) the working electrode prior to its direct or indirect determination by means of... 

Technique HG = hydride generation AAS = atomic absorption spectrometry GF = graphite furnace AES = atomic emission spectrometry MS = mass spectrometry AFS = atomic fluorescence spectrometry ASV = anodic stripping voltammetry SDDC = sodium diethyl dithiocarbamate. Procedures ISO = Memational Standards Organization ISO/CD = ISO Committee Draft SM = Standard Methods ... 

In this section the instrumentation and the experimental procedure to determine the Cd, Cu and Pb total dissolved concentration is described in some detail. Several reviews regarding the general theoretical and experimental aspects of anodic stripping voltammetry and its application in sea water (or natural water) analysis can be found in the literature (15 17, 41, 59, 62, 67, 68). Details of the speciation procedure are reported below. 

Other versatile and sensitive techniques for determination of metal ions in water are atomic absorption, which uses the attenuation of a beam of light of the appropriate wavelength by the atomized metal as the measure of concentration, and anodic stripping voltammetry, which is an electrochemical technique. Eurther details of all these procedures are available in standard texts ([20], and see also this chapter s Further Reading). 

The fuming HNO3 digestion procedure was used in conjunction with differential pulse anodic stripping voltammetry to determine sensitivity, linearity of response, measurement precision, and lead background or blank levels. Recovery studies, as well as some interference studies, were also conducted. It should be emphasized that the data presented in this discussion were obtained in a particular laboratory situation. Practical detection limits were determined both by the laboratory environment and by the ability of the analyst to reduce both the variability and magni-... 

Oehme, M. and Lund, W. (1979). Comparison of digestion procedures for the determination of heavy metals (Cd, Cu, Pb) in blood by anodic stripping voltammetry, Fres. Z. Anal. Chem. 298, 260-268... 

Kinard, J.R. (1977). Diagnosis of metal poisoning and evaluation of chelation therapy by differential pulse anodic stripping voltammetry coupled to a novel digestion procedure. Anal. Lett. 10,1147. 

The literature on procedures for PbB determination is abundant. Those techniques that have been shown to provide accurate and precise PbB determinations in routine use include anodic stripping voltammetry (ASV), flame atomic absorption spectrophotometry (FAAS), discrete sampling FAAS, and graphite furnace AAS (GF-AAS). The method most widely used for routine determination is AAS in its various modifications. The relatively slow analysis rate of ASV tends to limit the application of this technique to that of a backup or reference method. Whatever the technique which is applied, it should be emphasized that avoidance of contamination, careful handling of the blood samples and frequent intra- and interlaboratory checks are more important for ensuring precision and reliability than the method itself. 

A variety of spectrographic, colorimetric, polarographic, and other analytical techniques are used for routine measurement of silver in biological and abiotic samples. The detection limit of silver in biological tissues with scanning electron microscopy and X-ray energy spectrometry is 0.02 xg/kg and sometimes as low as 0.005 xg/kg. In air, water, and soil samples, the preferred analytical procedures include flame and furnace atomic absorption spectrometry, plasma emission spectroscopy, and neutron activation. Sensitive anodic stripping voltammetry techniques have recently been developed to measure free silver ion in surface waters at concentrations as low as 0.1 xg/L. 

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