The Experts below are selected from a list of 26052 Experts worldwide ranked by ideXlab platform
Carlos Bendicho - One of the best experts on this subject based on the ideXlab platform.
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chemical Sequential Extraction for metal partitioning in environmental solid samples
Journal of Environmental Monitoring, 2002Co-Authors: A V Filgueiras, I Lavilla, Carlos BendichoAbstract:A comprehensive review of the Sequential Extraction schemes for metal fractionation in environmental samples (i.e., sediment, soil, sewage sludge, fly ash, etc.) is presented. The review contains more than 400 references and covers principally the literature published over the last decade. The use of each reagent involved in these schemes is looked at critically, and guidelines for their selectivity and Extraction capacity are given. The operational character of these schemes is emphasised. Topics such as comparability between Sequential Extraction schemes of widespread use, harmonisation, acceleration, validation, etc. are addressed and future developments outlined.
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Speeding up of a three-stage Sequential Extraction method for metal speciation using focused ultrasound
Analytica Chimica Acta, 1998Co-Authors: B. Pérez-cid, Isela Lavilla, Carlos BendichoAbstract:The three-stage Sequential Extraction procedure, proposed by the European Community Bureau of Reference (BCR), has been applied for speciation of copper, chromium, nickel, lead and zinc in a sludge sample collected from an urban wastewater treatment plant. The conventional BCR Sequential Extraction method has been modified, in each stage, applying ultrasonic energy by means of a probe (handling at an adequate sonication power and time) in order to shorten the required operation time. Extractable metal contents obtained by both the conventional and the accelerated ultrasonic Extraction method, were measured by Flame-Atomic Absorption Spectrometry. Results obtained in each fraction by both methods were statistically compared (P=0.95) for all the studied elements and no significant differences were found except for chromium and zinc in the third fraction (oxidisable). For all metals the Extraction percentage was>95%. The proposed accelerated Sequential Extraction method could be a valid alternative to the conventional shaking with a much shorter operating time.
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ANALYTICAL ASSESSMENT OF TWO Sequential Extraction SCHEMES FOR METAL PARTITIONING IN SEWAGE SLUDGES
Analyst, 1996Co-Authors: B. Pérez-cid, Isela Lavilla, Carlos BendichoAbstract:Two Sequential Extraction schemes were employed for speciation of Cu, Cr, Pb, Ni and Zn in sewage sludges: the conventional Tessier scheme and the Sequential Extraction scheme proposed by the European Communities Bureau of Reference (BCR). Both Sequential Extraction schemes were compared in terms of operation time, matrix effects and Extraction efficiency. Two sludge samples collected from an urban wastewater processing plant at different seasons were analysed by FAAS for total contents and for extractable metals present in each fraction. Partitioning patterns were obtained for each metal so that metal mobility could be predicted. Both Sequential Extraction schemes yielded similar performance when Extraction efficiencies were compared but matrix effects caused by concomitants were less pronounced in the BCR scheme in comparison with the Tessier scheme.
H. Muntau - One of the best experts on this subject based on the ideXlab platform.
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certification of trace metal extractable contents in a sediment reference material crm 601 following a three step Sequential Extraction procedure
Science of The Total Environment, 1997Co-Authors: P. Quevauviller, G. Rauret, R. Rubio, J F Lopezsanchez, Allan M Ure, H. MuntauAbstract:Abstract Sequential Extraction schemes have been developed in the past 20 years for the determination of binding forms of trace metals in sediment. The lack of uniformity of these schemes, however, did not allow the results so far to be compared worldwide nor the procedures to be validated. Indeed, the results obtained by Sequential Extraction are operationally defined, i.e. the ‘forms’ of metals are defined by the determination of extractable elements using a given procedure. Therefore the significance of the analytical results is related to the Extraction scheme used. Another problem which hampered a good comparability of data was the lack of suitable reference materials which did not enable the quality of measurements to be controlled. Owing to this lack of comparability and quality control, the Community Bureau of Reference (BCR, now Standards, Measurements and Testing Programme) has launched a programme of which one of the aims was to harmonize Sequential Extraction schemes for the determination of extractable trace metals in sediment. This programme involved the comparison of existing procedures tested in two interlaboratory exercises, and it developed into a certification campaign of extractable trace element contents in a sediment reference material, following a three-step Sequential Extraction procedure duly tested and adopted by a group of 18 EU laboratories. This paper briefly describes the results of the interlaboratory studies and gives all details on the preparation of the sediment reference material, CRM 601, the homogeneity and stability studies and the analytical work performed for the certification of the extractable contents of some trace elements, following a standardized Sequential (three-step) Extraction procedure.
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Evaluation of a Sequential Extraction procedure for the determination of extractable trace metal contents in sediments
Fresenius' Journal of Analytical Chemistry, 1994Co-Authors: P. Quevauviller, G. Rauret, H. Muntau, R. Rubio, J. F. López-sánchez, H. D. Fiedler, B. GriepinkAbstract:The determination of extractable trace metals in sediments using Sequential Extraction procedures has been performed in many laboratories within the last ten years in order to study environmental pathways (e.g. mobility of metals, bounding states). However, the results obtained by different laboratories could hardly be compared due to lack of harmonized schemes. Owing to the need for standardization and subsequent validation of Extraction schemes for sediment analysis, the Measurements and Testing Programme (formerly BCR Programme) of the European Commission has organized a project to adopt a Sequential Extraction procedure that could be used as a mean of comparison of data of extractable trace metals in sediments. A scheme was designed after a series of investigations on existing schemes and tested in interlaboratory studies. This paper presents the results of two round-robin exercises on extractable trace metals using this Sequential Extraction protocol and describes the final version of the Extraction procedure amended according to the most recent improvements.
P. Quevauviller - One of the best experts on this subject based on the ideXlab platform.
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certification of trace metal extractable contents in a sediment reference material crm 601 following a three step Sequential Extraction procedure
Science of The Total Environment, 1997Co-Authors: P. Quevauviller, G. Rauret, R. Rubio, J F Lopezsanchez, Allan M Ure, H. MuntauAbstract:Abstract Sequential Extraction schemes have been developed in the past 20 years for the determination of binding forms of trace metals in sediment. The lack of uniformity of these schemes, however, did not allow the results so far to be compared worldwide nor the procedures to be validated. Indeed, the results obtained by Sequential Extraction are operationally defined, i.e. the ‘forms’ of metals are defined by the determination of extractable elements using a given procedure. Therefore the significance of the analytical results is related to the Extraction scheme used. Another problem which hampered a good comparability of data was the lack of suitable reference materials which did not enable the quality of measurements to be controlled. Owing to this lack of comparability and quality control, the Community Bureau of Reference (BCR, now Standards, Measurements and Testing Programme) has launched a programme of which one of the aims was to harmonize Sequential Extraction schemes for the determination of extractable trace metals in sediment. This programme involved the comparison of existing procedures tested in two interlaboratory exercises, and it developed into a certification campaign of extractable trace element contents in a sediment reference material, following a three-step Sequential Extraction procedure duly tested and adopted by a group of 18 EU laboratories. This paper briefly describes the results of the interlaboratory studies and gives all details on the preparation of the sediment reference material, CRM 601, the homogeneity and stability studies and the analytical work performed for the certification of the extractable contents of some trace elements, following a standardized Sequential (three-step) Extraction procedure.
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Evaluation of a Sequential Extraction procedure for the determination of extractable trace metal contents in sediments
Fresenius' Journal of Analytical Chemistry, 1994Co-Authors: P. Quevauviller, G. Rauret, H. Muntau, R. Rubio, J. F. López-sánchez, H. D. Fiedler, B. GriepinkAbstract:The determination of extractable trace metals in sediments using Sequential Extraction procedures has been performed in many laboratories within the last ten years in order to study environmental pathways (e.g. mobility of metals, bounding states). However, the results obtained by different laboratories could hardly be compared due to lack of harmonized schemes. Owing to the need for standardization and subsequent validation of Extraction schemes for sediment analysis, the Measurements and Testing Programme (formerly BCR Programme) of the European Commission has organized a project to adopt a Sequential Extraction procedure that could be used as a mean of comparison of data of extractable trace metals in sediments. A scheme was designed after a series of investigations on existing schemes and tested in interlaboratory studies. This paper presents the results of two round-robin exercises on extractable trace metals using this Sequential Extraction protocol and describes the final version of the Extraction procedure amended according to the most recent improvements.
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single and Sequential Extraction in sediments and soils
International Journal of Environmental Analytical Chemistry, 1993Co-Authors: P. Quevauviller, G. Rauret, B. GriepinkAbstract:Abstract The determination of extractable trace metal contents in soils and sediments is currently performed in many laboratories to assess the bioavailable metal fraction (and related potential phyto-toxic effects) and the importance and possibility of mobilization of trace metals from polluted soil, sludge and sediment upon landfill application. Single and Sequential Extraction schemes are used for the assessment of the different “forms” of trace metals (e.g. “mobile/bioavailable”, “carbonate-bound” etc.). The lack of uniformity in the different Extraction procedures used throughout the world does not allow the results to be compared or the procedures to be validated which has led to many criticisms in the past few years. Moreover, the lack of suitable reference materials for this type of operationally defined determinations did not enable the quality of the measurements to be controlled. Owing to the need for establishing common schemes for single and Sequential Extractions as well as for the improveme...
Michel Astruc - One of the best experts on this subject based on the ideXlab platform.
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fractionation studies of trace elements in contaminated soils and sediments a review of Sequential Extraction procedures
Trends in Analytical Chemistry, 2002Co-Authors: Christine Gleyzes, Sylvaine Tellier, Michel AstrucAbstract:Sequential selective Extraction techniques are commonly used to fractionate the solid-phase forms of metals in soils. Many Sequential Extraction procedures have been developed, particularly for sediments or agricultural soils, and, despite numerous criticisms, they remain very useful. This article reviews the reagents used in the various schemes, with their advantages and disadvantages. The particular case of elements giving anionic species is also developed. Finally, there is discussion of the limits of Sequential Extraction procedures.
Ornella Abollino - One of the best experts on this subject based on the ideXlab platform.
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Optimization of a Sequential Extraction procedure for trace elements in Arctic PM_10
Analytical and Bioanalytical Chemistry, 2020Co-Authors: Eleonora Conca, Agnese Giacomino, Mery Malandrino, Emanuele Costa, Francisco Ardini, Paolo Inaudi, Ornella AbollinoAbstract:In this work, a two-step Sequential Extraction scheme for the determination of trace elements in Arctic PM_10 samples was optimized by using two certified reference materials (CRMs). By means of an experimental design for qualitative variables, the five most common extracting solutions for particulate matter (PM) Sequential Extraction (high purity water (HPW), 0.032 M HNO_3, 0.022 M HCl, 0.11 M CH_3COOH, and 0.012 M CH_3COOH/CH_3COONH_4 buffer) and two different Extraction methods (stirring and ultrasounds) were compared. The purpose of the study was the identification of the procedure which gives the best estimation of the anthropogenic portion of the elements present in PM_10 samples. The use of ultrasounds instead of stirring induced a low but significant decrease of the Extraction of all the elements and a decrease in the repeatability of the procedure. Diluted HNO_3 was the extractant which allowed to maximize the Extraction of anthropogenic elements (As, Cd, Pb, Zn) with respect to crustal ones (Al, Si, Ti). The optimized procedure proved successful in avoiding contaminations and, therefore, suitable to be applied to PM samples having extremely low concentrations, such as samples collected in polar or other remote areas. The chosen procedure was applied to ten Arctic PM_10 samples, allowing for a better identification of their sources. Indeed, it was possible to hypothesize that even though the concentrations of As, Cd, K, Mg, Mn, and Ni in spring and summer were different, their mobility and, therefore, their chemical form in the analyzed PM_10 samples were probably similar. Graphical abstract
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The use of Sequential Extraction procedures for the characterization and management of contaminated soils.
Annali Di Chimica, 2005Co-Authors: Ornella Abollino, Agnese Giacomino, Mery Malandrino, Edoardo MentastiAbstract:Metal mobility and availability in solid samples, such as soils, sediments and sludges, is frequently studied with Sequential Extraction procedures, which allow to partition the total metal content into classes of different reactivity. From the experimental point of view, each Extraction step requires many practical operations, which can represent sources of error if they are not properly executed. The first part of the paper gives indication on how to perform Sequential Extractions, from sample pretreatment to extract analysis, in order to reduce experimental errors. The second part describes the main applications of Sequential Extraction schemes for the characterization and management of contaminated soils: the assessment of the risks associated to metal pollution, the evaluation of the feasibility and efficiency of remediation techniques, the study of soil properties and of metal behaviour and plant availability.
