Search results for "Metal speciation"
showing 6 items of 6 documents
Concentrations and forms of heavy metals in Slovak soils
2005
The risk assessment of heavy-metal contamination in soils requires knowledge of the controls of metal concentrations and speciation. We tested the relationship between soil properties (pH, CEC, Corg, oxide concentrations, texture) and land use (forest, grassland, arable) and the partitioning of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn among the seven fractions of a sequential extraction procedure in 146 A horizons from Slovakia. Using a cluster analysis, we identified 92 soils as representing background metal concentrations while the remaining 54 soils showed anthropogenic contamination. Among the background soils, forest soils had the lowest heavy-metal concentrations except for Pb (highest)…
Metal speciation in biological fluids — a review
1996
The literature on the speciation of metal ions in biological fluids is comprehensively reviewed. Critical examination on this subject reveals that major work has been done in blood and urine. Speciation in materials like milk has not yet been widely studied. On the other hand, only few references could be found on sweat, saliva, cell lysate, cerebrospinal, seminal, tear and bronchoalveolar fluids. The topics studied for these fluids were mainly the speciation of arsenic, mercury, aluminium and selenium. Work on the speciation of other elements like zinc, chromium, cadmium, lead, copper, iron etc. have also been carried out in such matrices. The present literature survey includes also a crit…
Metals distribution in the organic and inorganic fractions of soil: A case study on soils from Sicily
2005
The content of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, has been determined in the organic and inorganic fraction of eight soil samples from Sicily. A modified type-Tessier sequential extraction procedure has been used to recognize metals in five different fractions categorised as follows: (a) exchangeable metals, (b) metals bound to carbonates, (c) metals bound to iron and manganese oxides, (d) metals bound to organic matter, and (e) metals in residual fraction. The mineralogical composition of soils samples was characterized by X-ray diffraction. Humic substances were extracted by means of an alkaline extraction procedure. It has been found that both the mineralogical composition and the di…
Metal speciation in solid matrices
1994
The literature on metal ion speciation in solid matrices is reviewed, taking into account its applications in the analysis of soil, sediment, biological materials, foodstuff and other solid samples. The pretreatment methods of various solid materials required for carrying out speciation studies have been highlighted. The basis of the methods of separation of different species from matrices, such as sequential extraction, selective extraction, etc. is discussed. The instrumental techniques used for the characterization of different chemical species in solid matrices have been mentioned. The literature survey reveals the analytical details of the developed methodologies, and these have been e…
Elemental composition of seasoning products
2007
The elemental composition of seasoning products, like spices garlic and onion, has been reviewed paying special attention to methods proposed in the literature to determine specific elements or as much as possible components of these products which are widespread used in food preservation or food flavouring and can contribute to the intake of both, essential and toxic elements. Sample treatment and metal speciation aspects have been critically revised concerning onion, garlic and pepper (the most commonly studied products).
Metal distribution in road dust samples collected in an urban area close to a petrochemical plant at Gela, Sicily
2006
Eight samples of road dust were collected from three different localities (industrial, urban, peripheral) of the town of Gela (Italy) to characterize their chemical composition and to assess (a) the influence of the petrochemical plant and the urban traffic on the trace element content in different grain-size fractions of street dust and (b) the solid-phase speciation of the analysed metal using sequential extraction. The samples were sieved into six particle size ranges: 500–250, 250–125, 125–63, 63–40, 40–20 and <20 μm and then analysed for 15 trace elements by ICP-MS. Sequential extraction of metals was performed on each subsample. A principal component analysis was also carried out to d…