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Transformation of trace element speciation in disturbed soil profile
Kochergina, Yulia ; Mihaljevič, Martin (advisor) ; Vaněk, Aleš (referee)
Distributions of toxic trace elements were studied in soils before and after disturbation of their profiles.Two areas with different vegetation cover were selected: beech (Fagus sylvatica) and spruce (Picea abies) forests at the Načetín site in the Ore Mts. In the past, this area belonged to places with extreme levels of acidic atmospheric deposition. The studied areas are not placed too far from each other and have thus approximately the same climatic conditions, geological background and pollution input. On the other hand, physicochemical properties of soils (pH, CEC, BS, Ctot, Stot) and concentrations of major and trace elements are different. At selected sites in spruce and beech stand, two soil probes to a depth of 40-50 cm were dug in 2010 and samples of individual soil horizont were collected for chemical analyses (approximately 0.5 kg). Four samples from L, H, A and B horizons were taken in the spruce forest area and five samples from L, H, A, B and C horizons were taken in the beech forest. In 2011, the sites were re-sampled and samples were taken from horizons that were disturbed in 2010, paralleled by samples of undisturbed soil horizons from the same probe sites. Trace element concentrations were determined by ICP-MS, the speciation of individual elements in the soils was determined by...
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Transformation of trace element speciation in disturbed soil profile
Kochergina, Yulia
Distributions of toxic trace elements were studied in soils before and after disturbation of their profiles.Two areas with different vegetation cover were selected: beech (Fagus sylvatica) and spruce (Picea abies) forests at the Načetín site in the Ore Mts. In the past, this area belonged to places with extreme levels of acidic atmospheric deposition. The studied areas are not placed too far from each other and have thus approximately the same climatic conditions, geological background and pollution input. On the other hand, physicochemical properties of soils (pH, CEC, BS, Ctot, Stot) and concentrations of major and trace elements are different. At selected sites in spruce and beech stand, two soil probes to a depth of 40-50 cm were dug in 2010 and samples of individual soil horizont were collected for chemical analyses (approximately 0.5 kg). Four samples from L, H, A and B horizons were taken in the spruce forest area and five samples from L, H, A, B and C horizons were taken in the beech forest. In 2011, the sites were re-sampled and samples were taken from horizons that were disturbed in 2010, paralleled by samples of undisturbed soil horizons from the same probe sites. Trace element concentrations were determined by ICP-MS, the speciation of individual elements in the soils was determined by...
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Transformation of trace element speciation in disturbed soil profile
Kochergina, Yulia
Distributions of toxic trace elements were studied in soils before and after disturbation of their profiles.Two areas with different vegetation cover were selected: beech (Fagus sylvatica) and spruce (Picea abies) forests at the Načetín site in the Ore Mts. In the past, this area belonged to places with extreme levels of acidic atmospheric deposition. The studied areas are not placed too far from each other and have thus approximately the same climatic conditions, geological background and pollution input. On the other hand, physicochemical properties of soils (pH, CEC, BS, Ctot, Stot) and concentrations of major and trace elements are different. At selected sites in spruce and beech stand, two soil probes to a depth of 40-50 cm were dug in 2010 and samples of individual soil horizont were collected for chemical analyses (approximately 0.5 kg). Four samples from L, H, A and B horizons were taken in the spruce forest area and five samples from L, H, A, B and C horizons were taken in the beech forest. In 2011, the sites were re-sampled and samples were taken from horizons that were disturbed in 2010, paralleled by samples of undisturbed soil horizons from the same probe sites. Trace element concentrations were determined by ICP-MS, the speciation of individual elements in the soils was determined by...
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Distribution of trace elements in carbonatites using in-situ techniques, with focus on REE
Krátký, Ondřej ; Magna, Tomáš (advisor) ; Kynický, Jindřich (referee)
Carbonatites are unique and enigmatic magmatic rocks of unclear origin, with very specific mineralogy and geochemical properties. They are predominantly composed of magmatic calcite or other carbonate minerals (Le Bas 1987) and have low content of SiO2 (Le Maitre 2002). Origin of these peculiar magmas is still not clear but they appear to represent an important "window" into processes in Earth's mantle. They are considered either as residual melts from a fractionated carbonated nephelinite or melilitite (Gittins 1989; Gittins and Jago 1998), as immiscible fractions of CO2-saturated silicate melts (Freestone and Hamilton 1980; Amundsen 1987; Kjarsgaard and Hamilton 1988, 1989; Brooker and Hamilton 1990; Kjarsgaard and Peterson 1991; Church and Jones 1995; Lee and Wyllie 1997; Dawson 1998; Halama et al. 2005; Brooker and Kjarsgaard 2011), or as primary melts which are were generated from CO2-bearing peridotite through partial melting (Wallace and Green 1988; Sweeney 1994; Harmer and Gittins 1998; Harmer et al. 1998; Ying et al. 2004). Abundances of rare earth elements (REE) are often high in carbonatites because carbonatitic magmas can dissolve these elements much easily than silicate magmas (Nelson et al. 1988). Carbonatitic magma can also dissolve large quantities of Sr, Ba, P and mainly Zr and Nb,...
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Transformation of trace element speciation in disturbed soil profile
Kochergina, Yulia ; Mihaljevič, Martin (advisor) ; Vaněk, Aleš (referee)
Distributions of toxic trace elements were studied in soils before and after disturbation of their profiles.Two areas with different vegetation cover were selected: beech (Fagus sylvatica) and spruce (Picea abies) forests at the Načetín site in the Ore Mts. In the past, this area belonged to places with extreme levels of acidic atmospheric deposition. The studied areas are not placed too far from each other and have thus approximately the same climatic conditions, geological background and pollution input. On the other hand, physicochemical properties of soils (pH, CEC, BS, Ctot, Stot) and concentrations of major and trace elements are different. At selected sites in spruce and beech stand, two soil probes to a depth of 40-50 cm were dug in 2010 and samples of individual soil horizont were collected for chemical analyses (approximately 0.5 kg). Four samples from L, H, A and B horizons were taken in the spruce forest area and five samples from L, H, A, B and C horizons were taken in the beech forest. In 2011, the sites were re-sampled and samples were taken from horizons that were disturbed in 2010, paralleled by samples of undisturbed soil horizons from the same probe sites. Trace element concentrations were determined by ICP-MS, the speciation of individual elements in the soils was determined by...
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Problems, benefits and limitations of the determination of trace elements in hair.
ŽIŽKOVÁ, Věra
The thesis focuses on an evaluation of own experience in determining trace elements in hair and on gathering literature data from this area. The thesis concurrently attempts to answer the question of whether the determination of trace elements in hair is always relevant and beneficial or whether it poses certain limitations. The determination of trace elements in hair presents a number of advantages (i.e. easy and non-invasive sample collection, sample durability, small quantity) and it allows researchers to obtain otherwise hardly accessible retrospective information on the condition of the human body over a longer time horizon, often extending over several years. However, the determination of trace elements in hair also has its drawbacks and it requires researchers to resolve multiple problems. The use of hair cosmetics, for example, may have a potentially negative effect and there is the possible risk of hair contamination in the external or working environment. Therefore, when performing hair analysis, the first step is to clean (wash) the hair in an adequate manner so that external contaminants are removed as much as possible while endogenous elements are left intact. For this purpose, the methods recommended by IAEA, which include repeated washing and rinsing with the use of water and acetone, are often applied. The second critical step is hair mineralization, i.e. conversion to a solution. The common risks associated with this procedure are possible element loss due to e.g. evaporation caused by heat on one side and sample contamination by used reagents on the other side. Microwave mineralization with concentrated HNO3 and H2O2 additives seems as an ideal procedure in this respect. The own hair analysis may be effected by means of polarography or mass spectrometry with inductively coupled plasma. Nevertheless, the most frequently implemented method employs atomic absorption spectroscopy, namely flame atomisation for sufficiently high concentrations and electrothermal atomisation for low concentrations. Furthermore, method validation and standardisation are necessary for obtaining relevant information. For example, trueness should be verified through interlaboratory crosschecks (almost unavailable in the Czech Republic for the time being) or by using available reference material (e.g. BCR CRM 397). Precision is verified rather easily by repetitive homogenous sample analysis. In contrast to the discussed issues, commercial advertisements promise trouble-free, simple and easy, and sometimes even miraculous mapping of the health condition with distinct results and recommendations in the form of various food supplements. All may be naturally obtained after the payment of a specific amount (often paid repeatedly). How to answer, after summarizing data gathered from literature and own experience, the presented basic question on whether hair analysis is beneficial and generally applicable. In many cases, the answer may be yes. The thesis details examples of successful application when obtaining retrospective data on high expositions to Pb, Ni, Cd, Hg, and Fe: lead intoxication in a patient due to the long-term intake of a herbal concentrate containing lead, multiple-week monitoring of nickel content in the hair of a volunteer after a one-week exposition in an NiSO4 production environment, verification of Fe loss in a hemato-oncology patient, lead intoxication of an entire family as a result of long-term use of poor quality tableware, lead intoxication in historical painting conservators. As regards the commercial use of the individual result of the general population, it still seems rather problematic and the answer to the basic question is no. The determination of trace elements in hair is not beneficial and it cannot be generally applied that easily.
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