Arsenic environmental samples

Zinc smelters use x-ray fluorescence spectrometry to analyze for zinc and many other metals in concentrates, calcines, residues, and trace elements precipitated from solution, such as arsenic, antimony, selenium, tellurium, and tin. X-ray analysis is also used for quaUtative and semiquantitative analysis. Electrolytic smelters rely heavily on AAS and polarography for solutions, residues, and environmental samples. 

It is well known that arsenic is one of the most dangerous elements in terms of its potential impacts to both to human and ecosystem health. Therefore the problem of As detection at ppb level remains very important from the point of environmental hazard investigation. The goal of the present work is the developing of very simple and inexpensive assay for arsenite and arsenate determination in environmental samples using whole-cell bacterial biosensors. 

Smith, P.G. Koch, I. Gordon, R.A. Mandoli, D.F. Chapman, B.D., Reimer, K.J. 2005. X-ray absorption near-edge structure analysis of arsenic species for application to biological environmental samples. Environmental Science and Technology, 39, 248-254. 

J. Mattusch and R. Wennrich (1998) Determination of anionic, neutral, and cationic species of arsenic by ion chromatography with ICPMS Detection in environmental samples.- Anal. Chem. 70,3649 - 3655. 

Arsenic recoveries from the zinc column in the range 0.1-5pg ml-1 arsenic exceeded 97%. The concentrations at which certain elements interfere are shown in Table 12.16. Various other elements [A1 m, B m, Ca II, Cd II, Co II, Cr VI, Fe III, K I, Li I, Mg II, Mn H, Na I, Ni II, Pb II, S VI, Sn II and Zn II] showed no significant interference at the 500pg level. Only low senium concentrations in extracts can be tolerated. However, few environmental samples contain appreciable amounts of selenium. As selenium is not reduced to hydrogen selenide on the column, selenium will not interfere in the final determination step, but probably suppresses either arsenic reduction or arsine formation. Selenium appears to suppress arsine generation at high arsenic concentrations but causes a slight enhancement at low arsenic concentrations (around O.lpg), which could not be traced to arsenic impurities in the selenium standard used. 

The chemical form of arsenic in marine environmental samples is of interest from several standpoints. Marine organisms show widely varying concentrations of arsenic [4-6] and knowledge of the chemical forms in which the element occurs in tissues is relevant to the interpretation of these variable degrees of bioaccumulation and to an understanding of the biochemical mechanisms involved. Different arsenic species have different levels of toxicity [7] and bioavailability [8] and this is important in food chain processes, while physicochemical behaviour in processes such as adsorption onto sediments also varies with the species involved [9]. It has... 

S. A. Pergantis, W. R. Cullen and A. P. Wade, Simplex optimisation of conditions for the determination of arsenic in environmental samples by using electrothermal atomic absorption spectrometry, Talanta, 41(2), 1994, 205-209. 

Francesconi, K.A., Edmonds, J.S. and Morita, M. (1994) Determination of arsenic and arsenic species in marine environmental samples, in Arsenic in the Environment Part I Cycling and Characterization (ed. J.O. Nriagu), John Wiley Sons, Inc., New York, pp. 189-219. 

Pizarro, I., Gomez, Ma.M., Camara, C. and Palacios, Ma.A. (2003) Distribution of arsenic species in environmental samples collected in northern Chile. International Journal of Environmental Analytical Chemistry, 83(10), 2879-90. 

Leermakers, M., W. Baeyens, M. De Gieter, et al. 2006. Toxic arsenic compounds in environmental samples Speciation and validation. Trends Anal. Chem. 25(1) 1-10. 

Some metals are of particular interest in environmental samples, and specific methods for these have been developed. Arsenic, chromium, and mercury are all important in this respect, having very differing toxicities in different forms. 

Fishbein L. 1984. Overview of analysis of carcinogenic and/or mutagenic metals in biological and environmental samples I. Arsenic, beryllium, cadmium, chromium and selenium. Int J Environ Anal Chem 17 113-170. 

The term speciation is used to describe any analytical procedure in which the amounts of an element in discrete chemical forms are determined, as opposed to the total amount of an element in the sample. For example, it may be of interest to determine the amounts of Cr3 + and Cr042 in environmental samples, if the two ionic species have different toxicities, rather than the total amount of chromium. In this instance ion exchange may be used to separate the cationic and anionic species.23 Sometimes all the species to be determined may be either cationic or anionic, as in the case of the determination of Fe2+ and Fe3+ or S2, S032-, and S042-. Sometimes inorganic and organically bound forms may be determined, as in the case of arsenic species in natural waters.24 Where flame spectrometric determination has been employed in speciation studies of this type, selected key references may be found in the element-by-element section of Chapter 6. 

E. Vassileva, H. Docekalova, H. Baelen, S. Vanhentenrijk, M. Hoenios, Revisitation of mineralisation modes for arsenic and selenium determination in environmental samples, Talanta, 54 (2001), 187-196. 

Z. Slejkovec, A. R. Byme, B. Smodis, M. Rossbach, Preliminary studies on arsenic species in some environmental samples, Fresenius J. Anal. Chem., 354 (1996), 592-595. 

Sass, S., T.L. Fisher, M.H. Stutz and R.J. Piffadi. 1970. Analysis of Environmental Samples from Area of Sheep Deaths near Dugway Proving Ground (U). EASP 100-69, Department of the Army, Edgewood Arsenal, MD. 

Vassileva, E., Docekalova, H., Baeten, H., Vanhentenrijk, S., Hoenig, M. Revisitation of mineralization modes for arsenic and selenium determinations in environmental samples. Talanta 54, 187-196 (2001)... 

Gomez-Ariza, J.L., Sanchez-Rodas, D., frunaculada, G.I., Morales, E. A comparison between ICP-MS and APS detection for arsenic speciation in environmental samples. Talanta 51, 257-268 (2000)... 

Arsenic Species Commonly Found in Environmental Samples... 

Talmi, Y. and Norvell, U.E. Determination of arsenic and antimony in environmental samples using gas chromatography with a microwave emission spectrometric system. Anal. Chem. 47, 1510-1516 (1975). 

Laboratory methods. Huorimetry has been used widely for selenium analysis in environmental samples but is being superseded by more sensitive instrumental methods. Some of the instmmental methods used for arsenic speciation and analysis can also be used for selenium. In particular, HPLC and HG can separate selenium into forms suitable for detection by A AS, AFS (Ipolyi and Fodor, 2000), or ICP-AES (Adkins et al, 1995). Only Se(IV) forms the hydride, and so Se(VI) must be prereduced to Se(IV) if total selenium is to be determined. This is normally achieved using warm HCl/KBr followed by co-precipitation with La(OH)3 if necessary (Adkins et al., 1995). KI is not used, since it tends to produce some Se(0), which is not reduced by HG. La(OH)3 collects only Se(IV), so the prereduction step to include the contribution from Se(VI) is required before co-precipitation. Other methods of preconcentration include co-precipitation of Se(IV) with hydrous iron oxide or adsorption onto Amberlite IRA-743 resin (Bueno and Potin-Gautier, 2002). 

The gas chromatography-microwave plasma detector (GC-MPD) technique has been applid to the analysis of alkyl arsenic acids in environmental samples . 

P. Richter, R. Seguel, I. Ahumada et al.. Arsenic Speciation in Environmental Samples of a Mining Impacted Sector of Central Chile, J. Chilean Chem. Soc. 49(4), 333-339, Dec. (2004). 

Copper was determined with cuproine in silicate rocks, biological materials, and sea water [112,113], in environmental samples [113], steel and cast iron [114]. Neocuproine was used for determination of copper in biological materials [12,115], foods [116], sea water [117], beryllium [118], arsenic and gallium [119], tungsten [120], aluminium alloys [117], plutonium [121], tellurium [122], and fertilisers [123]. Bathocuproine was applied in determinations of copper in blood serum [124,125], water [126,127], niobium, tantalum, molybdenum, and tungsten [128], lead and nickel [129], cast iron and steel [66]. 

Chan CC, Sadana RS. 1992. Determination of arsenic and selenium in environmental samples by flow-injection hydride generation atomic absorption spectrometry. Anal Chim Acta 270(l) 231-238. 

DOE. 1987. A cathodic stripping technique for the determination of trace levels of arsenic and selenium in waste, organic, and environmental samples. Report to U.S. Department of Energy by Martin Marietta Energy Systems, Inc., Oak Ridge, TN. DOE K/PS-5078. DE88-002257. 

Table 5.5 Examples of arsenic compounds found in environmental samples...

PoNGRATZ R (1998) Arsenic speciation in environmental samples of contaminated soil. Sci Total Environ 224 133-141. 

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