Fractionation studies of trace elements in Polish uranium-bearing geological materials: potential environmental impact

The samples of U deposits from Podlasie Depression (East Poland) and Peribaltic Syneclise (Northeast Poland) were studied to state the U and accompanied metal content and to estimate a potential environmental impact caused by the studied area. Sequential extraction is an effective method for assessing the heavy metal behaviour in environment in such environmental materials as soils, sediments, different wastes and ores.

The modified Bureau of Reference of the European Commission sequential extraction procedure has been used for fractionation study of nine elements (U, V, Mn, Co, Ni, Cu, Zn, Cd and Pb) in two kinds of U ores: dictyonema shale and sandstone. The total content and the content in each fraction of metals of interest were determined by the inductively coupled plasma mass spectrometry method.

The obtained results show the high mobility of such elements as Co, Zn and Ni in shale and U, Co and Mn in sandstone. These results make it possible to assess the environmental risk associated with heavy metals occurring in tested U-bearing ores.     

Solution extraction of transition and post-transition heavy and precious metals by chelate and macrocyclic ligands

This review focuses on compounds and methods that can be used for the extraction and separation from solution of two classes of elements that we define as heavy metals and precious metals. These elements are often targeted because they are toxic, costly, and their coordination chemistry has already been well studied, and because there is a need to develop methods of economically extracting, separating and recovering them from waste sites. This review outlines possible strategies that can be used, and reviews the present literature regarding the available methods for their extraction.     

Investigation of the binding properties of heavy-metal-peptide complexes in plant cell cultures using HPLC-ICP-MS

Metal-induced, sulfhydryl-rich peptides (phytochelatins) found in plants, algae, yeasts and fungi have been described as sequesters and detoxifiers of heavy metal ions. High-performance liquid chromatography (HPLC) coupled on-line with inductively coupled plasma mass spectrometry (ICP-MS) has been used for the determination of heavy metal binding properties of phytochelatins in Silene vulgaris cell cultures. The induction of phytochelatins and the binding of heavy metals to these complexes were investigated by exposure of cell cultures with different concentrations of Cd, Cu, Pb and Zn. An in vitro heavy metal saturation assay and in vivo stress experiments with those elements able to bind to phytochelatins were carried out in order to characterize the binding affinity and binding stability of these compounds. It is shown that of the metals investigated, Cu binds most stably to phytochelatins under in vitro and in vivo conditions.     

A hyphenated flow-through analytical system for the study of the mobility and fractionation of trace and major elements in environmental solid samples

A flow-through hyphenated analytical method has been tested that enables not only the accelerated and efficient fractionation of trace elements (TE) species in environmental solids to be achieved but allows real-time studies on the leaching process to be made. Rotating coiled columns (RCC), earlier used mainly in countercurrent chromatography, have been successfully applied to the dynamic fractionation of heavy metals in soil, sediment, and sludge samples. A ground solid sample (about 0.5 g) was retained in a PTFE rotating column as the stationary phase whereas different aqueous eluents, chosen according to recent data on the selectivity of leachants, were continuously pumped through. Elements were determined in the effluent on-line by inductively coupled plasma atomic emission spectrometry (ICP-AES). Since the flow rates used in the RCC are in good agreement with those needed for cross-flow nebulization in the ICP-AES spectrometer, both devices were coupled directly without any additional interface systems. Simultaneous investigation of the elution profiles of trace and major elements has made it possible to study the elements association in separated fractions and hence to prove the efficacy of extractants and their selectivity toward targeted mineralogical phases of samples. The close association of heavy metals with Mn oxides in the sediment and sludge samples was confirmed. The time-resolved dissolution of different organic complexes of metals was observed for the sediment sample. It was found that in sediment and sludge samples the dynamics of iron release under the action of Tamm's reagent is somewhat different from that of aluminium. In addition, the proposed method can also be applied to develop effective leaching schemes and in the analysis of environmental solids for risk assessment of their contaminants addressed to water quality and bioavailability.     

Complexation as the most important factor in the fate and transport of heavy metals in the Dnieper water bodies

The results of long-term investigations of the concentrations of dissolved forms of some heavy metals (Mn, Cu, Zn, Pb, Cr, Cd) and their species in the water of the Dnieper reservoirs and the Dnieper-Bug estuary are considered. Chemiluminescent methods, anodic stripping voltammetry, membrane filtration, ion-exchange, and gel-permeation chromatography were used for study of the speciation of the metals. It has been found that binding of heavy metals into complexes with dissolved organic matter (DOM) is the dominant factor of their stabilization in solution. The molecular weight distribution of organic metal complexes and their chemical nature, as well as the potential complexing ability of DOM were investigated. Humic substances, particularly fulvic acids, play a major role in the complexation. These ligands bind from 45 to 80% of metals in the form of organic complexes. Metal complex compounds of relatively low molecular weight (<5 kDa) predominated in the organic complexes.     

Comparison of some newly synthesized chemically modified Amberlite XAD-4 resins for the preconcentration and determination of trace elements by flow injection inductively coupled plasma-mass spectrometry (ICP-MS)

XAD copolymer resins may be functionalized with heavy metal ion-selective ligands either by covalent linkage to the polymer backbone or by impregnation. These resins may be tailored to be specific for certain heavy metals by adjusting the retention and elution parameters. For the synthesis of immobilized Amberlite XAD-4 copolymer resins that are expected to preconcentrate a number of transition and heavy metals, the Schiff base method was chosen. For this purpose the copolymer was nitrated, reduced to the corresponding amine and converted to the imine compounds via a Schiff base reaction using different organic aldehyde compounds. The interactions of 8 elements (Cd, Co, Cu, Mn, Ni, Pb, U and Zn) with the resins were qualitatively investigated. Optimal pH for retention was typically 6-8 for most resins although one could be used at pH 5 and elution was achieved using 0.1 M HNO3. The resins were characterized by FTIR, SEM and elemental analysis. It was demonstrated that the resins could be used to preconcentrate ultra-trace analytes from natural waters, and analysis of environmental certified reference materials using FI-ICP-MS showed good agreement with the certified values. Metal retention capacities were also calculated using a batch system and were found to compare favorably with other resins reported in the literature.     

Adsorption of Uranium (VI) Ions on Hydrazinyl Amine and 1,3,4-Thiadiazol-2(3 H)-thion Chelating Resins

Nitrogenous compounds are the most widely used in solid phase extraction due to its low cost, easy convertible to many functional groups. These have large adsorptive capacity toward heavy metal ions as rare earth elements (REEs) and uranium with ability for recovering from low concentrate solutions. Synthesis of resins were carried out by polymerization of acrylonitrile with divinyl benzene as crosslinker. Treatment of the resulted precipitate with hydrazine hydrate in ethanol produce hydrazinyl methyl amine which has high chelating capacity toward uranyl ions. 1,3,4-Thiadiazol-2(3H)-thion derivative was yielded by reaction of hydrazinyl amine with carbon disulfide in methanol. This reaction carried out in the presence of methyl benzoate and dioctyl phthalate as pore producing solvent which used to improve physical properties and adsorptive character of the resins. Optimization on the two resins during loading and elution were carried out using solution with different concentrations. The optimum factors during adsorption and elution were recognized.     

Determination of toxic and trace elements in algae by instrumental neutron activation analysis

Instrumental neutron activation analysis has been applied in the determination of toxic and other trace elements in a set of three algae materials provided by the International Atomic Energy Agency, with the aim of environmental preservation through enhanced applications of nuclear analytical techniques. The quality of the analysis method has been evaluated by analyzing a number of biological standard reference materials. By adding mineral nutrients, the cultivation of algae for metals is enhanced, in particular, selected toxic heavy metals such as As, Cd, Cr, Hg, Ni and Pb. It is believed that the level of elemental concentration in algae samples are dependent on environmental conditions due to its biochemical properties. Therefore, algae materials may be useful as an indicator or controller of environmental water pollution.     

Polyanionic Clusters and Networks of the Early p-Element Metals in the Solid State: Beyond the Zintl Boundary

Reduction of p-element (post-transition) metals and metalloids by alkali metals leads to many salts containing polyatomic clusters or network anions of these elements. The earliest solvated examples were referred to as Zintl ions. Synthetic explorations have now established that many of the clusters can in fact be obtained from neat (solvent free) high-temperature reactions of binary to quaternary systems, particularly for the heavier tetrel (group 14) and triel (group 13) elements. Some synthetic tricks have also proven useful. Electronic guidelines such as Wade's rules, known to account well for other types of electron-deficient cluster bonding, are widely applicable to these compounds, but numerous hypoelectronic (electron-poor) trielide salts have also been discovered. These developments also extend to related infinite network structures and Zintl (valence) compounds. The Zintl boundary designation traditionally delineated the tetrel elements that form salts with the active metals from those of the triel and earlier elements that were once thought to generate only intermetallic phases. The distinction no longer seems appropriate, at least with regard to some alkali-metal compounds of the triel elements.     

Distribution and speciation of platinum group elements in environmental matrices

The use of platinum group elements (PGEs) as components of autocatalytic converters attached to motor vehicles has resulted in serious contamination of the environment by Pt, Rh and Pd in nanocrystalline forms. Trace concentrations of PGEs, particularly the major component Pt, in environmental samples have been measured by sensitive instrumental procedures. These data have raised further questions about the nature of Pt species in contaminated soils and in plants grown in them. The focus of attention is changing from accumulations of data expressing total concentrations to investigations of speciation. Application of analytical procedures for research on speciation has provided information concerning transformations of Pt compounds in contaminated soils, the uptake of Pt by plants and the nature of Pt compounds in vegetation. Determination of background levels of precious metals in clinical and environmental matrices has required the development of analytical methods which combine uses of minimal quantities of reagents, and as small a number of chemical operations as possible to yield very low procedural blanks. Sensitive instrumental methods based upon high resolution inductively coupled plasma mass spectrometry and adsorptive stripping voltammetry have proven to be valuable for this work.     

Determination of the elemental distribution in cigarette components and smoke by instrumental neutron activation analysis

Cigarette smoking is a major source of particles released in indoor environments. A comprehensive study of the elemental distribution in cigarettes and cigarette smoke has been completed. Specifically, concentrations of thirty elements have been determined for the components of 15 types of cigarettes. Components include tobacco, ash, butts, filters, and cigarette paper. In addition, particulate matter from mainstream smoke (MS) and sidestream smoke (SS) were analyzed. The technique of elemental determination used in the study is instrumental neutron activation analysis. The results show that certain heavy metals, such as As, Cd, K, Sb and Zn, are released into the MS and SS. These metals may then be part of the health risk of exposure to smoke. Other elements are retained, for the most part, in cigarette ash and butts. The elemental distribution among the cigarette components and smoke changes for different smoking conditions.     

垃圾焚烧飞灰颗粒的微观形态特征及能谱研究

利用SEM/EDX，观察了垃圾焚烧飞灰颗粒的微观形态特征，探讨了其主要组成元素及其质量分数。实验结果表明，飞灰颗粒形态多样化，其中以不规则形状聚合体居多，球形体、絮状集合体相对较少，少数颗粒为棒状集合体。球形飞灰颗粒很少有重金属分布，不规则形状聚合体或絮状集合体的表面易分布重金属。从飞灰颗粒表面、内部组成元素的质量分数来看，Si、Ca、Al为主要元素。飞灰颗粒表面、内部有重金属Pb、Cu等分布，局部测定点其质量分数可高达16.2%和14.5%。     

Content of micronutrients,mineral and trace elements in some Mediterranean spontaneous edible herbs

Background

The analysis of mineral elements composition was determined in three wild edible herbs (Cichorium intybus L., Sonchus asper L. and Borago officinalis) collected in seven different sampling sites which were characterized by different pollution grade. The detection of mineral elements (Ca, K, Mg and Na), micronutrients (Cu, Fe, Li, Mn and Zn) and heavy metals (As, Cd, Hg, Ni and Pb) was performed.

Results

The results obtained show that in most cases a direct relationship appeared between the amount of elements and the sampling sites. The highest concentrations of heavy metals were found in samples grown in polluted soils. These evaluations showed that contaminants in plants may reflect the environmental state in which they develop.

Conclusion

The examined species are a good source of mineral elements and micronutrients, making them particularly adapt to integrate a well-balanced diet. The accumulation of heavy metals showed that contaminants in plants may reflect the environmental state in which they develop. Results showed high concentrations of heavy metals in samples taken in locations characterized by high human activity and in some samples from the local market, of which no one knows the collection area.

     

Analysis of heavy metals and sulphur-rich compounds in the water moss Fontinalis antipyretica L. ex Hedw.

The water moss Fontinalis antipyretica has been investigated to estimate heavy metal pollution in the river Elbe (middle Germany). Procedures of plant separation, digestion as well as an analytical method for ICP-MS analyses have been evaluated. Reproducibility and accuracy have been demonstrated on BCR 61 (NIST) reference material and results have been compared with AAS and AES data. The distribution of heavy metals in different plant segments of indigenous material has been analyzed. Exposition of plant material in the river Elbe have shown no correlation between the heavy metal content in plants and that of water samples. Cd and Zn concentrations found in the plant material are significantly enriched relatively to control samples. To understand the sophisticated ‘real system’ experiments have been carried out under laboratory conditions to investigate induced sulphur-rich compounds in the presence of heavy metals using HPLC including on-line derivatization.     

稀土在中国高新材料研制开发中的应用

我国在稀土资源和稀土原料的生产方面都居世界领先地位，近年来稀土高新材料的研制与开发也取得重大进展。本文概述了我国在稀土高新材料开发与研究方面的成果，指出今后应把稀土应用基础研究、中重稀土的应用研究和稀土在能源领域的应用研究作为重点进一步开展工作。     

Perspectives of analysis of carcinogenic and mutagenic metals in biological samples

There is a continuing need to assess the status of exposure to humans of the carcinogenic and/or mutagenic metals in both biological and environmental samples to better ensure that current or past exposures do not entail unacceptable health risks or to detect potentially excessive exposure before the appearance of adverse health effects. In order to more readily evaluate both the extent of exposure and trends of human exposure as well as the bioavailability, bioaccumulation and transport of these elements and their compounds, sensitive analytical procedures are required for their determination of the various oxidative states (as well as their organic derivatives) in complex matrices such as those found in both environmental and biological samples. The major objective of this overview is to highlight the more recent trends and state-of-the-art methodologies for the determination and speciation of arsenic, selenium, cadmium, chromium and nickel in human and animal tissues while concomitantly noting germane aspects of their bioavailability and interactions. Aspects of biological monitoring of the above elements will be stressed due to their potential utility in augmenting diverse epidemiologic and occupational health studies.     

Transition Metals in the Synthesis and Functionalization of Indoles [New Synthesis Methods (72)]

The use of transition-metal complexes as reagents for the synthesis of complex organic compounds has been under development for at least several decades, and many extraordinary organic transformations of profound potential have been realized. However, adoption of this chemistry by the practicing synthetic organic chemist has been inordinately slow, and only now are transition-metal reagents beginning to achieve their rightful place in the arsenal of organic synthesis. Several factors contributed to the initial reluctance of synthetic organic chemists to use organometallic reagents. Lacking education and experience in the ways of elements having d electrons, synthetic chemists viewed organometallic processes as something mysterious and unpredictable, and not to be discussed in polite society. Organometallic chemists did not help matters by advertising their latest advances as useful synthetic methodology, but restricting their studies to very simple organic systems lacking any serious functionality (e.g., the “methyl, ethyl, butyl, futile” syndrome). Happily, things have changed. Organometallic chemists have turned their attention to more complex systems, and more recently trained organic chemists have benefited from exposure to the application of transition metals. This combination has set the stage for major advances in the use of transition metals in the synthesis of complex organic compounds. This review deals with one aspect of this area, the use of transition metals in the synthesis of indoles.     

Heavy-metal distribution in river waters and sediments around a "firefly village", Shikoku, Japan: application of multivariate analysis.

River water and sediment samples were collected at the same site in a vicinity of an abandoned mine, and the concentrations of major elements and heavy metals were determined. The chemical correlations were observed by principal component analysis (PCA), and the samples were classified by cluster analysis (CA) based on the PCA scores. The PCA results presented a macroscopic viewpoint of covariance structure, i.e., the chemical elements could be classified into three groups: 1) major elements and heavy metals in the river water, 2) Cd, Fe and Mn in the sediments, and 3) Cu and Zn in the sediments. The CA results implied a similarity of chemical compositions in most parts of the study area, except the ranges close to the abandoned copper mine. At the mixing location of mining water with natural river water, major elements and cadmium showed simple physical mixing (conservative mixing). Other heavy metals (Cu, Fe, Mn and Zn) showed the massive precipitation at the mixing event. The PCA structure was mainly interpreted in terms of the mixing process between mining water and diluted natural river water.     

Determination of trace heavy metals in biological samples by inductively-coupled plasma atomic emission spectrometry after extraction with 1,5-bis-(di-2-pyridylmethylene)thiocarbonohydrazide

A sensitive inductively-coupled plasma atomic emission spectrometric sequential method for the determination of trace heavy metals (cadmium, cobalt, copper and nickel) in biological samples after extraction of the metals into isobutyl methyl ketone (IBMK) containing 1,5-bis-(di-2-pyridylmethylene)thiocarbonohydrazide (DPTH) is described. A systematic study was made to determine the optimum conditions for extraction of the metals into IBMK. The complexes formed are quite soluble in IBMK, so much so that this allows the use of aqueous-to-organic phase volume ratios of up to 40 and hence the determination of concentrations down to 40 times lower than those afforded by the direct non-extractive method. The method has been used for the determination of these elements in various biological materials with good results.