Elemental speciation

Moreover, GC-ICP-MS has also been utilized for the analysis of TBDMS derivatives of alkyl phosphonic acid degradation products in river water and soil extracts [25]. In addition, the same group investigated the analysis of TBDMS derivatives of alkyl phosphonic acid degradation products in the presence of common herbicides and pesticides [14]. Kroening et al. [26] recently reviewed the use 

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Vol. 135. Element Speciation in Bioinorganic Chemistry. Edited by Sergio Caroli... 

Okamoto K and Yoshinaga J (1999) Proper use of reference materials for elemental speciation studies. In Fajgelt A and Parkany M, eds. The use of matrix reference materials in environmental analytical processes, pp 46-56. Royal Sodety of Chemistry, Cambridge. 

ICP-MS Multielement detection Trace elements Speciation Expensive [36]... 

HPLC-QFAAS is also problematical. Most development of atomic plasma emission in HPLC detection has been with the ICP and to some extent the DCP, in contrast with the dominance of the microwave-induced plasmas as element-selective GC detectors. An integrated GC-MIP system has been introduced commercially. Significant polymer/additive analysis applications are not abundant for GC and SFC hyphenations. Wider adoption of plasma spectral chromatographic detection for trace analysis and elemental speciation will depend on the introduction of standardised commercial instrumentation to permit interlaboratory comparison of data and the development of standard methods of analysis which can be widely used. 

Plasmas compare favourably with both the chemical combustion flame and the electrothermal atomiser with respect to the efficiency of the excitation of elements. The higher temperatures obtained in the plasma result in increased sensitivity, and a large number of elements can be efficiently determined. Common plasma sources are essentially He MIP, Ar MIP and Ar ICP. Helium has a much higher ionisation potential than argon (24.5 eV vs. 15.8 eV), and thus is a more efficient ionisation source for many nonmetals, thereby resulting in improved sensitivity. Both ICPs and He MIPs are utilised as emission detectors for GC. Plasma-source mass spectrometry offers selective detection with excellent sensitivity. When coupled to chromatographic techniques such as GC, SFC or HPLC, it provides a method for elemental speciation. Plasma-source detection in GC is dominated by GC-MIP-AES... 

Applications ICP-MS has become the technique of choice for the determination of elements in a wide range of liquid samples at concentrations in the ng L 1 to [igL-1 range. Typical applications of ICP-MS are multi-element analysis of liquids (even with high solid contents) element speciation by hyphenation to chromatographic techniques continuous on-line gas analysis multi-element trace analysis of polymers and trace analysis in high-purity materials. ICP-MS is routinely used for quality control purposes. 

LA-ICP-MS allows quick simultaneous oligo-element homogeneity determinations in mg samples of polymeric material. Coupling of ICP-MS to chromatographic techniques provides element speciation capabilities, especially as a detector for LC. Kingston et al. [417] have described a speciated technique for the determination of Cr(III) and Cr (VI) by HPLC-ICP-MS. 

R. Comehs, J. Camso, H. Crews and K. Heumann (eds), Handbook of Elemental Speciation, John Wiley Sons, Ltd, Chichester (2003/4), 2 vols. 

L. Ebdon, L. Pitts, R. Comehs, H. Crews, O.F.X. Donard and Ph. Quevauviller (eds), Trace Element Speciation for Environment, Food, Health, The Royal Society of Chemistry, Cambridge (2001). 

J.A. Camso, K.L. Sutton and K.L. Ackley (eds), Elemental Speciation - New Approaches for Trace Element Analysis, Elsevier, Amsterdam (2000). 

G.R. Batley (ed.), Trace Element Speciation Analytical Methods and Problems, CRC Press, Boca Raton, FL (1987). 

Photothermal Spectroscopy Methods for Chemical Analysis. By Stephen E. Bialkowski Element Speciation in Bioinorganic Chemistry. Edited by Sergio Caroli Laser-Enhanced Ionization Spectrometry. Edited by John C. Travis and Gregory C. Turk Fluorescence Imaging Spectroscopy and Microscopy. Edited by Xue Feng Wang and Brian Herman... 

FACTORS AFFECTING TRACE ELEMENT SPECIATION IN SOIL SOLUTION... 

Trace element speciation in soil solution is affected by total metal concentrations in soils. Free Cu2+ activity increases with total Cu content in soils from Quebec and New York (Sauve et al., 1997). Total free Cu activity in soils could be predicted from total Cu content and soil pH ... 

Carbonates, organic matter, Fe and Mn oxides, and clay minerals play important roles in controlling overall reactivity of trace elements in soils and sediments. This chapter addresses the interaction of trace elements with carbonates, organic matter, Fe and Mn oxides and clay minerals. Analytical techniques for trace element speciation in solid-phase and their distribution among various solid-phase components in arid and semi-arid soils are reviewed. Solubilities of trace elements in solid phases and their mineralogical characteristics in arid and semi-arid soils also are discussed. 

ANALYTICAL TECHNIQUES FOR TRACE ELEMENT SPECIATION IN SOLID-PHASE... 

Ball, J. W, E. A. Jenne and D. K. Nordstrom, 1979, WATEQ2 - a computerized chemical model for trace and major element speciation and mineral equilibria of natural waters. In E. A. Jenne (ed.), Chemical Modeling in Aqueous Systems, American Chemical Society, Washington DC, pp. 815-835. 

B Hymer C, Brisbin J, Sutton K, Caruso JA. New approaches for elemental speciation using plasma mass spectrometry. Am. Lab. 2000 32 17-39. 

On the basis of the preceding discussion, it should be obvious that ultratrace elemental analysis can be performed without any major problems by atomic spectroscopy. A major disadvantage with elemental analysis is that it does not provide information on element speciation. Speciation has major significance since it can define whether the element can become bioavailable. For example, complexed iron will be metabolized more readily than unbound iron and the measure of total iron in the sample will not discriminate between the available and nonavailable forms. There are many other similar examples and analytical procedures that must be developed which will enable elemental speciation to be performed. Liquid chromatographic procedures (either ion-exchange, ion-pair, liquid-solid, or liquid-liquid chromatography) are the best methods to speciate samples since they can separate solutes on the basis of a number of parameters. Chromatographic separation can be used as part of the sample preparation step and the column effluent can be monitored with atomic spectroscopy. This mode of operation combines the excellent separation characteristics with the element selectivity of atomic spectroscopy. AAS with a flame as the atom reservoir or AES with an inductively coupled plasma have been used successfully to speciate various ultratrace elements. 

A USGS model for computing the major and trace element speciation and mineral saturation for natural waters. 

In the final section of the book, Part V, Water-Waste Interaction, various approaches to describe and predict the interaction between waste and water are presented. This part of the book does not only deal with landfills containing different types of municipal waste forms, but also with different nuclear waste forms. Of special interest are laboratory experiments on waste form corrosion and element speciation in aqueous media that represent realistic disposal... 

The environmental risk leachates from the retort residue represent on the ecosystem is not only related to the absolute content of various potentially toxic trace elements in the semicoke, which in most cases may not be significantly higher than the content of the natural oil shales. It also depends on the leachability of these elements when the residue comes in contact with water, and on the elemental speciation. Important factors to consider in this context are ... 

Eighmy, T. T., Eusden, J. D. Jr., Krzanowski, J. E., Domingo, D., Stampfli, D., Martin, J. R. Erickson, P. M. 1995. Comprehensive approach towards understanding element speciation and leaching behavior in municipal solid waste electrostatic precipitator ash. Environmental Science Technology, 29, 629-646. 

It is not possible to prescribe specific pretreatment procedures here because these can only be decided upon when the system and the purpose of the experiments has been properly defined. However, a wealth of information exist in various biochemical reference books on how to isolate various biological compounds. The recommended techniques and methods could be used as part of the trace element speciation protocol often after slight modification, taking into consideration the following points First, the trace element blank levels have to be low, less than 10% of the total concentration in the sample. Second, the regents used should not interfere with subsequent analytical determinations. Third, the experimental conditions should not deviate markedly from those found in vivo, especially the pH and ionic strength of the medium. 

Although the emphasis in this article has been on the discussion of toihniques and methods that can be used in the laboratory for the identification of species, increasing importance is being attached to computer simulation of trace element speciation. The reason for this increased interest could be attributed in part to the availability of relevant experimental data which could be used in developing the required models. However, computer simulation comes into its own when the species are so imstable that separation techniques cannot be applied and/or the detection systems do not have the required sensitivity. 

Rosenberg, E., in Handbook of Elemental Speciation II, Species in the Environment, Food, Medicine and Occupational Health, R. Cornelis, J. Caruso, H. Crews, K. G. Heumann (eds.). John Wiley Sons Ltd., Chichester (2005). 

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