Copper stripping analysis

METHOD DEVELOPMENT FOR THE POTENTIOMETRIC STRIPPING ANALYSIS OF SOLUBLE COPPER IN DENTAL MATERIALS... 

Potentiometric stripping analysis has been applied by Sheffrin and Williams [320] to the measurement of copper in seawater at environmental pH. The advantage of this technique is that it can be used to specifically measure the biologically active labile copper species in seawater samples at desired pH values. The method was applied to seawater samples that had passed a 0.45 pm Millipore filter. Samples were studied both at high and at low pH values. 

The way that the stripping analysis is performed in practice is much more sophisticated. After the solution has been exhausted, all of the copper (as Cu (Hg) amalgam) resides on the surface of the mercury drop. The potential of the drop is changed from cathodic to anodic (we say that we have stepped the potential), and the copper is all oxidized back to Cu and the charge determined - as oxidation-The potential chosen should be more positive than E for the analyte couple by at least 0.2 V. 

Accumulation of Cu(II) complexes with xanthine and xanthosine has also been utilized in stripping analysis [74]. Copper(II) indapamide complex was adsorptively accumulated at a HMDE and used for the determination of the ligand in the cathodic stripping step [75]. 

Town, R.M. (1998) Chronopotentiometric stripping analysis as a probe for copper(II) and lead(II) complexation by fulvic acid limitations and potentialities. Anal. Chim. Acta, 363, 31-43. 

Potentiometric stripping analysis, as stated in one review,92 "is not as general an analytical technique for the determination of metal traces as is graphite-furnace atomic absorption spectroscopy." It is used as a complementary technique for assay of some toxic metals in water (zinc, cadmium, lead, and copper in potable water and wastewater,93 94 and lead and thallium in seawater.95 The advantage of anodic stripping voltammetry (ASV) is summarized in two steps, which include electrolytic preconcentration and the stripping process. There are a number of interfering ions that can affect the... 

A study of seawater by stripping analysis reveals an anodic copper peak having a height of 0.13 /xA when deposition is carried out at —0.5 V. However, deposition at —1.0 V yields a larger peak of 0.31... 

Adsorptive stripping voltammetry (ASV) is another specialised technique where the SMDE electrode is used for reducible species and carbon paste electrodes for oxidisable ones. This allows enrichment (by factors of 100-1000) of ions at the working electrode before stripping them off for measurement this improves the detection limits. This technique is rapid, sensitive (10 "M), economical and simple for trace analysis. The basic instrumentation for stripping analysis is apotentiostat (with voltammetric analyser), electrode and recorder. While voltammetry is generally very useful for compounds that do not have a chromophore or fluorophore, stripping analysis is the best analytical tool for direct, simultaneous determination of metals of environmental concern, e.g. lead, cadmium, zinc and copper in sea water. 

Amperometric techniques are very useful for detecting analytes that have been separated by chromatographic means but have no chromophores or other easy means of detection. Adsorptive stripping voltammetry (ASV) can be used for the direct sensitive analysis of metals in many types of sample matrix. For example, ASV has been used to determine cadmium, lead and zinc in urine, copper and bismuth in human hair tin in fruit juice, zinc and copper in fish and lead in gunshot residue. Stripping analysis can also be used for other applications such as determining flavanols in wine °, inorganic compounds such as cyanide and pharmaceuticals. ... 

Fig. 2. Potentiometric stripping analysis in a whole blood sample. Deposition for two min at -1.2 V (Curve I). Curves II and III are the corresponding response after standard additions of 8 and 16/tM copper, respectively. (From Jagner et al., 1981).

Huiliang, H., Jagner, D. and Renman, L. (1987b) Simultaneous determination of mer-cury(ll), copper(ll) and bismuth(lll) in urine by flow constant-current stripping analysis with gold fiber electrode. Anal. Chim. Acta, 202,117-122. 

Soares, H.M.V.M., Vasconcelos, M.T.S.D., 1995. Application of potentiometric stripping analysis for speciation of copper complexes with adsorbable ligands on the mercury electrode. Anal. Chim. Acta 314, 241-249. 

Wil] Chemical analysis of carbon content and calculation of carbon activity in (yFe) phase. Pure iron-copper strip and metastable iron carbide as a carbon source placed in the sealed tubes were heated in furnace from 24 h at 1050°C to 7 d at 850°C, then the tubes were quenched to room temperature. Fe-alloys with 0.72, 1.36, 3.13, 5.61, 6.74 mass% Cu and 0.2 to 1.5 mass% C. Measurements at 850, 925 and 1050°C. 

Potentiometric stripping analysis (PSA) is another commonly used technique in water analysis. This technique can usually be applied directly to the analysis of water samples without previous treatment, and it is virtually free from interferences of dissolved oxygen. Both, PSA and ASV techniques are based on the same principle the anal) e is first deposited on the electrode surface while the solution is stirred, and then stripped back to the solution in the measurement step [14,22,196]. The ASV technique works on a film electrode (electrochemically deposited mercury or gold on a glassy carbon support). One advantage of PSA is that it requires simpler equipment than ASV, and can compete with nonelectroanalytical techniques in terms of price, and possibility of automation [247-249]. This method has been applied to determine metals in tap water and rainwater samples [250-253], coupled with FIA to determine copper in natural waters [254,255], etc. In addition, portable PSA instruments have also been developed, and demonstrated to be useful for metals determination in aquatic samples [256-259]. 

Saei-Dehkordi, S.S. andFallah, A.A. (2011) Determination of copper, lead, cadmium and zinc content in commercially valuable fish species from the Persian Gulf using derivative potentiometric stripping analysis. Microchem. J., 98 (1), 156-162. 

Cadmium, copper, lead Flow potentiometric stripping analysis - [61]... 

Metalloimmunoassays for proteins based on stripping analysis of copper- and silver-enhanced " AuNPs as well as silver nanoparticle labels have also been reported. One problem with all dissolution-based strategies for electrochanical detection of nanoparticle or enhanced nanoparticle labels is that dissolution often involves anploying toxic or corrosive reagents, for example, hydrobromic acid/bromine mixture for AuNPs and nitric acid for silver nanoparticles and copper- or silver-enhanced AuNPs. In one study, electrooxidation and complexation with thiocyanate was used as an alternative to dissolve silver nanoparticles in place of nitric acid for anodic stripping detection of myoglobin. ... 

Baldo MA, Daniele SD, Ciani I, Bragatto C, Wang J (2003) Remote stripping analysis of lead and copper by a mercury-coated platinum microelectrode. Electroanalysis 16 360-366... 

Wang E, Sun W, Yang Y (1984) Poteaitiranetric stripping analysis with a thin-film gold electrode for determination of copper, bismuth, antimmiy, and lead. Anal Chem 56 1903— 1906... 

Legeai S, Bois S, Vittori O (2006) A copper bismuth film electrode for adsorptive cathodic stripping analysis of trace nickel using square wave voltammetry. J Electroanal Chem 591 93-98... 

Yang W, Gooding JJ, Hibbert DB (2001) Characterisation of gold electrodes modified with self-asseanbled monolayers of L -cysteine for the adsorptive stripping analysis of copper. J Electroanal Chem 516 10-16... 

Jagner D, Aren K (1979) Potentiometric stripping analysis for zinc, cadmium, lead and copper in sea wato. Anal Chim Acta 107 29-35... 

Hardcastle JL, Compton RG (2001) The electroanalytical detection and determination of copper in heavily passivating media ultrasonically enhanced solvent extraction by N-benzoyl-N-phenyl-hydroxylamine in ethyl acetate coupled with electrochemical detection by sono-square wave stripping voltammetry analysis. Analyst 126 2025-2031... 

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. 

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