Natural Environment Monitoring 2009, No 10, pp. 35-44
EFFICIENCY AND SELECTIVITY OF REAGENTS USED TO CHEMICAL FRACTIONATION OF HEAVY METALS IN ENVIRONMENTAL SOLID SAMPLE
Ryszard Świetlik, Marzena Trojanowska
Total concentration of metals in environmental samples does not provide suitable information about mobility and bioavailability of potentially toxic elements. It is now widely recognized that the toxicity and the mobility of metals depend strongly on their specific chemical forms and physical phases. Single and sequential extraction methods have been widely applied to characterize the chemical forms of metals in solid samples. Sequential selective extraction techniques are commonly used to chemical fractionation the solid-phase forms of metals in environmental samples. Many sequential extraction schemes have been developed for different solid samples (sediments, soils, slugdes). Despite numerous criticisms, extraction procedures remain very useful in environmental studies and are considered an essential tool in establishing element fractionation in solid phase. This article reviews the most commonly reagents used in the various procedures. From this review, it appears that all reagents used in various schemes have advantages and disadvantages. The choice of procedure must be related to a definite objective, taking into account nature of the sample and selectivity of the reagents used in the procedure.