Copper , anodic stripping voltammetry

The concentration of copper in a sample of sea water is determined by anodic stripping voltammetry using the method of standard additions. When a 50.0-mL sample is analyzed, the peak current is 0.886 )J,A. A 5.00-)J,L spike of 10.0-ppm Cu + is added, giving a peak current of 2.52 )J,A. Calculate the parts per million of copper in the sample of sea water. 

Scarponi et al. [93] used anodic stripping voltammetry to investigate the contamination of seawater by cadmium, lead, and copper during filtration and storage of samples collected near an industrial area. Filtration was carried... 

Muzzarelli and Sipos [622] showed that a column of chitosan (15 x 10 mm) can be used to concentrate zinc from 3 litres of seawater before determination by anodic-stripping voltammetry with a composite mercury-graphite electrode. Zinc (and lead) are eluted from the column by 2 M ammonium acetate (50 ml), copper by 0.01 M EDTA (10 ml), and cadmium by 0.1 M potassium cyanide (3 ml). 

Brugmann et al. [680] compared three methods for the determination of copper, cadmium, lead, nickel, and zinc in North Sea and northeast Atlantic waters. Two methods consisted of atomic absorption spectroscopy but with preconcentration using either freon or methyl isobutyl ketone, and anodic stripping voltammetry was used for cadmium, copper, and lead only. Inexplicable discrepancies were found in almost all cases. The exceptions were the cadmium results by the two atomic absorption spectrometric methods, and the lead results from the freon with atomic absorption spectrometry and anodic scanning voltammetric methods. 

Scarponi et al. [781] studied the influence of an unwashed membrane filter (Millpore type HA, 47 mm diameter) on the cadmium, lead, and copper concentrations of filtered seawater. Direct simultaneous determination of the metals was achieved at natural pH by linear-sweep anodic stripping voltammetry at a mercury film electrode. These workers recommended that at least 1 litre of seawater be passed through uncleaned filters before aliquots for analysis are taken the same filter can be reused several times, and only the first 50-100 ml of filtrate need be discarded. Samples could be stored in polyethylene containers at 4 °C for three months without contamination, but losses of lead and copper occurred after five months of storage. 

Nygaard et al. [752] compared two methods for the determination of cadmium, lead, and copper in seawater. One method employs anodic stripping voltammetry at controlled pH (8.1,5.3 and 2.0) the other involves sample pretreatment with Chelex 100 resin before ASV analysis. Differences in the results are discussed in terms of the definition of available metal and differences in the analytical methods. 

Cuculic and Branica [788] applied differential pulse anodic stripping voltammetry to a study of the adsorption of cadmium, copper, and lead in seawater onto electrochemical glass vessels, quartz cells, and Nalgene sample bottles. Nalgene was best for sample storage and quartz was best for electroanalytical vessels. 

Batley [28] examined the techniques available for the in situ electrodeposition of lead and cadmium in estuary water. These included anodic stripping voltammetry at a glass carbon thin film electrode and the hanging drop mercury electrode in the presence of oxygen and in situ electrodeposition on mercury coated graphite tubes. Batley [28] found that in situ deposition of lead and cadmium on a mercury coated tube was the more versatile technique. The mercury film, deposited in the laboratory, is stable on the dried tubes which are used later for field electrodeposition. The deposited metals were then determined by electrothermal atomic absorption spectrometry, Hasle and Abdullah [29] used differential pulse anodic stripping voltammetry in speciation studies on dissolved copper, lead, and cadmium in coastal sea water. 

A kind of standard additions approach can also be used for the measurement of apparent complexing capacity. In this technique, labile copper is measured by differential pulse anodic stripping voltammetry after each of a number of spikes of ionic copper have been added to the sample [420]. 

The determination of copper is also discussed under Multi-Metal Analysis of Soils in Sect. 2.55 (atomic absorption spectrometry), Sect. 2.55 (emission spectrometry), Sect. 2.55 (inductively coupled plasma atomic emission spectrometry), Sect. 2.55 (photon activation analysis), Sect. 2.55 (neutron activation analysis), Sect. 2.55 (electron probe microanalysis) and Sect. 2.55 (differential pulse anodic stripping voltammetry). 

Figure 8.3 Schematic representation of copper concentrations relevant to freshwater studies and analytical windows of several analytical techniques. ASV, anodic stripping voltammetry CSV, cathodic stripping voltammetry ISE, ion selective electrode SLM, supported liquid membrane SWASV, square wave anodic stripping voltammetry LC50, lethal concentration for 50% of the population [Cu]t, total metal concentration (adapted from Langford and Gutzman, 1992).

Martinotti, W., Queirazza, G., Guarinoni, A. and Mori, G. (1995) In-flow speciation of copper, zinc, lead and cadmium in fresh waters by square wave anodic stripping voltammetry Part II. Optimization of measurement step. Anal. Chim. Acta, 305, 183-191. 

Plavsic, M., Krznaric, D. and Branica, M. (1982) Determination of the apparent copper complexing capacity of seawater by anodic stripping voltammetry. Mar. Chem., 11, 17-31. 

Deaver, E. and Rodgers, J.H., Jr (1996) Measuring bioavailability of copper using anodic stripping voltammetry. Environ. Toxicol. Chem., 15, 1925-1930. 

The four variations of this technique are to be found in Table 14.2. The schemes of operation are shown in Fig. 14.6. Important applications for trace metals are the use of anodic stripping voltammetry (ASV) to determine trace quantities of copper, cadmium, lead and zinc, and adsorptive stripping voltammetry (AdSV) of trace quantities of nickel and cobalt—pre-concentration by adsorption accumulation of the oxime complexes followed by reduction to the metal is employed, as reoxidation of these metals in ASV is kinetically slow and does not lead to well-defined stripping peaks. 

Anodic stripping voltammetry (ASV) was applied to the determination of copper traces present as Cu(dik)2. The differential pulse technique was used to strip the amalgamated copper from a hanging mercury drop electrode. The experimental variables such as scan rate of electrode potential, deposition potential, deposition time and stirring speed of the solution could be optimized. The linear range of the calibration plot was 0.05-1 (xM and the LOD was 0.014 fiM Cu(II). A method was used for the determination of copper in breast milk and beer as typical examples of application, consisting of minerahzation of the sample, extraction of Cu(II) from the aqueous solution with a 1 M solution of acacH in chloroform and ASV end analysis . 

Automated Anodic Stripping Voltammetry for the Measurement of Copper, Zinc, Cadmium, and Lead in Seawater... 

M. L. Landy, An evaluation of differential pulse anodic stripping voltammetry at a rotating glassy carbon electrode for the determination of cadmium, copper lead and zinc in Antarctic snow samples. Anal. Chim. Acta, 121 (1980), 39-49. 

Piotrowicz, S. R., Harvey, G. R., Springer-Young, M., Courant, R. A., and Boran, D. A. (1983b). Studies of cadmium, copper, and zinc interactions with marine fiilvic and humic materials in seawater using anodic stripping voltammetry. In Trace Metals in Seawater (C. S. Wong, J. D. Burton, K. Bruland, and E. D. Goldberg, eds.). Plenum, New York, pp. 699-717. 

Bhat, G. A., Saar, R. A., Smart, R. B., and Weber, J. H. (1981). Titration of soil-derived fulvic acid by copper(n) and measurement of free copper(II) by anodic stripping voltammetry and copper(II) selective electrode. Anal. Chem. 53, 2275 -2280. 

Duinker, J. C., and C. J. M. Kramer (1977), An Experimental Study on the Speciation of Dissolved Zinc, Cadmium, Lead, and Copper in River Rhine and North Sea water, by Differential Pulsed Anodic Stripping Voltammetry, Marine Chem. 5, 207 228. 

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