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.F. . Rubio , R. . Rauret , G. . Quevauviller , P. Ure A. M. AND Muntau H. , 1994 . Study of the stability of extractable trace metal contents in a river sediment using sequential extraction . Analyst. 119 . 1109 - 1114

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Abollino, O. et al., 2006. Assessment of metal availability in contaminated soil by sequential extraction. Water Air and Soil Pollution. 137. 315–338. Awad, F., Fuda, S. & Arafat, S. M., 1984. A

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Filgueiras, A. V., Lavilla, I., Bendicho, C. (2002): Chemical sequential extraction for metal partitioning in environmental solid samples. J. Environ. Monit. , 4 , 823–857. Bendicho C

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Abstract  

The predictions of a sequential extraction scheme with respect to the mobility of some radionuclides (85Sr,134Cs and110mAg) in two Mediterranean sandy and sandy-loam soils, are compared to short-term soil-to-plant transfer factors and soil migration. Total soil-to-plant transfer is higher in sandy soil than in sandy-loam soil, as expected and predicted by the scheme. The relative transfer to plants of134Cs and85Sr follows the scheme predictions about exchangeable radionuclide fraction, radiosilver being less mobile than expected. Migration in soil of radiocesium and radiostrontium is also higher in sandy soil, especially for the latter radionuclide, the relative behavior of these two radionuclides being nearer to the bioavailable radionuclide fraction defined by the scheme. However, the scheme fails in predicting radiosilver migration, which is lower than deduced by the scheme.

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Abstract  

The environmental mobility/availability behavior of radionuclides in soils and sediments depends on their speciation. Experiments have been carried out to develop a simple but robust radionuclide sequential extraction method for identification of radionuclide partitioning in sediments and soils. The sequential extraction protocol was optimized for temperature, concentration of reagents and reaction time. Optimum extraction conditions were chosen based on the release of 239,240Pu, 238U and stable elements. Results from the experiments with lake sediment (SRM 4354) are compared to the previous trials where the sequential extraction protocol was optimized with the ocean sediment (SRM 4357). Based on these two trials the NIST standard sequential extraction protocol is established for defined extraction settings for temperature, reagent concentration and time.

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Abstract  

An approach based on sequential extraction separation and the subsequent ICP-MS measurement was introduced to determine 99Tc in radioactive wastes. The radwastes were firstly alkaline-fused and the 99Tc was separated by a sequential solvent extraction prior to ICP-MS measurement. NaDDC was selected as a chelation reagent in the solvent extraction processes. The influence of HCl and matrix concentration on the recovery yield and the effectiveness of removing isobar and unwanted radionuclides, such as 137Cs, 54Mn, 60Co and 110mAg, were evaluated. The designed sequential extraction procedure was optimized by an extraction experiment. The proposed technique is proven to be a simple and practical alternative for 99Tc determination in low-level radioactive wastes; chemical separation of 99Tc can be simplified and preconcentration such as precipitation and/or ion exchange, before the solvent extraction, can be excluded.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Yi-Lin Jan
,
Tsing-Hai Wang
,
Ming-Hsu Li
,
Shih-Chin Tsai
,
Yuan-Yaw Wei
,
Chun-Nan Hsu
, and
Shi-Ping Teng

Abstract  

A good understanding of the migration of selenite, Se(IV), through deep granitic layers depends on a good understanding of the geochemistry of these layers. Chemical sequential extraction is applied herein to evaluate the ability of granite to adsorb Se(IV) in DW, GW and SW systems. The experimental results indicate that the removal of crystalline Fe oxides reduces the adsorption of Se(IV), suggesting its importance in granite. The normalized concentrations of Se(IV) adsorbed onto crystalline Fe oxides is approximately 0.0301, 0.0330 and 0.0335 mole Se(IV) adsorbed/mole of Fe in DW, GW and SW systems. Kinetic adsorption experiments are conducted to elucidate the results of the chemical sequential extraction. Both the treated and the untreated granite take the same time to reach their equilibrium, suggesting that crystalline Fe oxides dominate the adsorption of Se(IV). Meanwhile, the one-site model suffices to simulate the kinetics of adsorption.

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Abstract  

The operationally defined bioavailable fraction from a commonly used sequential extraction (SE) procedure was compared to biological availability represented by plant uptake of137Cs and90Sr. Experiments were conducted at two locations in the Ukraine and at several field locations on the Savannah River Site, South Carolina. A significant regression existed between plant uptake and the ammonium acetate fraction (r 2=0.65), however, ratios of predicted uptake from the SE procedure to observed plant uptake ranged from 0.03 to 5.2 Data suggest that SE procedure was useful for qualitative interpretations of biological availability but lacked sufficient rigor to be useful for quantitative predictions.

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Abstract  

In order to study the foliar uptake of radionuclides deposited from an aerosol released in an accidental situation, lettuce plants were contaminated with an aerosol containing85Sr,134Cs and110mAg isotopes. The methodology chosen to carry out this study is based on a sequential extraction scheme using water, to evaluate the fraction possibly removed by rain or by washing, and an organic solvent, to distinguish between the fraction adhering to the cuticle and the one incorporated in the leaves. Two procedures are compared. Moreover, the different behavior of the radionuclides in their incorporation into the leaves is deduced from the results obtained.

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Abstract  

Three kinds of soil, collected in various places (in northwestern and southeastern Poland and near Chernobyl) were used as a subject of sequential extraction and plutonium distribution study. The modified method of Tessier was applied to separate readily available, carbonate, organic, Fe/Mn oxide and residual fractions. Plutonium isotope activity in soil as well as in particular separated fractions was determined by means of alpha spectrometry. The method of plutonium separation and purification for alpha-spectrometric measurements was modified according to the chemical properties of the extracted fraction. It was found that the major part (about 90%) of 239,240Pu is bound to organic and Fe/Mn oxide fractions (in uncultivated soil samples of northwestern Poland and Chernobyl). In soil samples coming from river valley (southeastern Poland) almost equal amounts of plutonium are distributed between the available, organic and residual fractions.

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