%0 Journal Article
%T Heavy Metal and Trace Metal Analysis in Soil by Sequential Extraction: A Review of Procedures
%A Amanda Jo Zimmerman
%A David C. Weindorf
%J International Journal of Analytical Chemistry
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/387803
%X Quantification of heavy and trace metal contamination in soil can be arduous, requiring the use of lengthy and intricate extraction procedures which may or may not give reliable results. Of the many procedures in publication, some are designed to operate within specific parameters while others are designed for more broad application. Most procedures have been modified since their inception which creates ambiguity as to which procedure is most acceptable in a given situation. For this study, the Tessier, Community Bureau of Reference (BCR), Short, Gal¨¢n, and Geological Society of Canada (GCS) procedures were examined to clarify benefits and limitations of each. Modifications of the Tessier, BCR, and GCS procedures were also examined. The efficacy of these procedures is addressed by looking at the soils used in each procedure, the limitations, applications, and future of sequential extraction. 1. Introduction Soils are the reservoir for many harmful constituents, elemental and biological, including heavy metals and trace metals, henceforth referred to as just metals [1]. Total metal content of soils is useful for many geochemical applications but often the speciation (bioavailability) of these metals is more of an interest agriculturally in terms of what is biologically extractable [2]. Speciation is defined by Tack and Verloo [3] as ¡°the identification and quantification of the different, defined species, forms or phases in which an element occurs¡± and is essentially a function of the mineralogy and chemistry of the soil sample examined [4]. Quantification is typically done using chemical solutions of varying, but specific, strengths and reactivities to release metals from the different fractions of the examined soil [5]. In terms of bioavailability, various species of metals are more biologically available than others [6]. If bioavailability and the mobility of metals are related, then the higher the concentration of mobile toxic metals (Cu, Pb, Cd, and Al) in the soil column which increases the potential for plant uptake, and animal/human consumption [3, 7, 8]. Determination of metals in soil can be accomplished via single reagent leaching, ion exchange resins, and sequential extraction procedures (SEP), the latter under controversy. The number of available extraction techniques developed over the last three decades begs inquiry as to which technique is preferable over another. Moreover, the nonselectivity of the reagents used, handling of sediment prior to extraction, sediment-reagent ratio, and length of extraction all have an effect on data
%U http://www.hindawi.com/journals/ijac/2010/387803/