Single and Sequential Extraction

Single and sequential extraction schemes have been designed in earlier years and widely used to assess the different retention/release of metals in soil and sediment samples (Tessier et al., 1979 Salomons and Forstner, 1980 Thomas et al., 1980 Meguellati et al., 1987). However, the lack of uniformity in the different procedures used did not allow the results to be compared worldwide or the procedures to be... 

Classical speciation of radionuclides is described in Chapter 13. Methodology for single and sequential extraction of soil to assess radionuclide availability to plants is similar to that used for heavy metals, and has recently been reviewed (Kennedy et al., 1997). Therefore, only recent applications of sequential extraction to speci-ate both natural and anthropogenic nuclides are discussed below. 

Kennedy, VH., Sanchez, A.L., Oughton, D.H. and Rowland, A.R (1997) Use of single and sequential extractants to assess radionuclide and heavy metal availability from soil to roots. Analyst, 122, 89R-100R. 

McGrath, D. (1996) Application of single and sequential extraction procedures to polluted and unpolluted soils. Sci. Total Environ., 178, 37-44. 

Ure, A.M., Davidson, C.M. and Thomas, R.P. (1995) Single and sequential extraction schemes for trace metal speciation in soil and sediment. Tech. Instr. Anal. Chem., 17, 505-523. 

Batchwise kinetic leaching is aimed at understanding both the rate and extent of TE remobilization by changes in environmental scenarios. Moreover, this tecluiique has the potential to overcome the recognized limitation of phase overlapping of several extractants (e.g., the single and sequential extractants of SM T procedures) whenever the several pools attacked feature different kinetic behavior. Contributions of readsorption phenomena to the thermodynamic leachate results may also be discerned by evaluation of kinetic data (Bermond et al., 1998). Manual fractionation protocols based on kinetic explorations are capable of... 

The diversity and complexity of the available approaches has identified the major difficulties associated with producing suitable guidelines that would allow comparisons between different laboratories and different countries in assessing metal mobility in the soil environment. This led to the development of single and sequential extraction procedures by the Standards, Materials and Testing (SM T - formerly the (European) Community Bureau of Reference (BCR) Programme of the European Union (1987)). Single extractants evaluated included 0.05 moll-1 EDTA, 0.43 moll-1 acetic acid, and 1 moll-1 ammonium acetate at pH 7. 

Specific chapters then focus on different projects on speciation analysis. Chapter 4 deals with interlaboratory studies on methylmercury in fish and sediment Chapter 5 describes the collaborative projects to certify organotins in sediment RMs and mussel tissues Chapter 6 gives an overview of the certification project on trimethyllead in simulated rainwater and urban dust Chapter 7 describes the certification project on arsenic species in fish tissues Chapter 8 focuses on the intercomparison and tentative certification of Se(IV) and Se(VI) in simulated freshwater Chapter 9 deals with a feasibility study to stabilize Cr species in solution followed by the certification of Cr(III) and Cr(VI) in lyophilized solutions and welding dust Chapter 10 gives a review of methods used for A1 speciation Chapter 11 develops the overall collaborative project to standardize single and sequential extraction procedures for soil and sediment analysis, followed by interlaboratory studies and certification of soil and sediment reference materials. 

Single and Sequential Extraction Table 11.5 Stability tests second step... 

Fiedler, Enrique Barahona, Manuel Lachica, Alain Gomez, Geffrey Bacon, Catherine Davidson, Herbert Muntau for the project on single and sequential extraction... 

Schramel, O., MichaUce, B., Kettmp, A., 2000, Study of the copper distribution in contaminated soils of hop helds by single and sequential extraction procedures. Sci. Total Environ. 263, 11-22. 

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