Application of chemical reagent for soil mercury extraction in speciation studies

Soil mercury speciation, aiming at quantitative identification of mercury species in the medium, provides useful information of toxicology, bioavailability and biogeochemical activity that are inaccessible even with only total mercury determination. Actually, mercury mobility depends strongly on its different chemical forms that will defining its transport pathway: immobilised in soil, volatilised to atmosphere, plant uptake, carried into other soil-compartment as well as into hydrosphere (groundwater, lake, river and ocean). For this purpose, it is a prime importance to use an appropriate chemical reagent(s) to extract soil Hg-species and, thus, the key to speciation determination is the appropriate choice of reagent. Nevertheless, neither specific extractants nor standard protocols exist for the isolation of particular mercury forms. Although there has been considerable research focused on reagents for extracting mercury species, there is still little consensus. Among the discussions, sequential extraction approach, using a series of reagents, has been suffered from operational interpretation while a single extraction study, more specific approach using one reagent, seems to be scarce. For this reason, our work emphasises the validation of a sole reagent using for the latter manner. Beside this, the interferences causing by reagent used and soil matrix have been taken into account. As the matter of fact, we demonstrate, in our presentation, the selected reagent and its convenient operational conditions for soil mercury extraction. Once the pertinent reagent is defined, the feasibility of a kinetic fractionation methodology and its associated experimental results will be presented as a specifying tool of soil mercury mobility.

کلیدواژه ها:

Contaminated Soil ، Kinetic Fractionation ، Matrix Interference ، Reagent Interference ، Mercury Extraction ، Speciation