Trace Elements In Solution Research Articles

Calibration Standard Samples for Multielement Analysis of Silicate Rocks Using Inductively Coupled Plasma Mass Spectrometry with Laser Ablation

A comparison of different standard samples—artificial glass SRM-612 (Standard Reference Material) and standard samples of natural composition SG-1A, SG-3, ST-1A, and SGD-1A—used for external calibration in the elemental analysis of silicate rocks in the form of fused glasses by inductively coupled plasma mass spectrometry and laser ablation (LA-ICP-MS) is carried out with a goal of selecting the most suitable samples for plotting the calibration dependence upon determination of the major and trace elements when using LA-ICP-MS for routine analysis. The results showed that the error of determination for both major and trace elements is lower (compared to SRM-612) when external calibration is carried out using the reference materials of natural composition with Si and Fe contents close to those in the analyzed samples. The use of internal standards in both cases decreases the systematic error attributed to the drift of LA parameters and different ablation yields. The correctness of the determination of 28 elements is proved in comparison of the results of the analysis of four standard samples with the reference values. The obtained results are used to select calibration standards for LA-ICP-MS analysis of the samples of unknown composition. The results of analysis of six samples of unknown composition match within the error limit the results of X-ray fluorescence analysis (major elements) and ICP-MS (trace elements in solutions). Refining of the content of trace elements in the previously certified reference materials allows them to be used for calibration in routine analysis of geological rocks. The developed LA-ICP-MS technique is a rapid method for determination of a wide range of elements, in particular, rare earth elements, in silicate rocks and can be used for routine analysis without additional sample preparation after X-ray fluorescence analysis.

Assessment of mobile and potential mobile trace elements extractability in calcareous soils using different extracting agents

Understanding trace elements mobility in soils, extracting agents, and their relationships with soil components, are essential for predicting their movement in soil profile and availability to plants. A laboratory study was conducted to evaluate extractability of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), and zinc (Zn) from calcareous soils utilizing various extracting agents to be specific CaCl2, DTPA, EDTA, HNO3, MgCl2, NaNO3, NH4NO3, and NH4OAc. Cluster analysis indicated that DTPA and NH4OAc, HNO3 and EDTA, and MgCl2 and NH4NO3 extracting agents yielded comparative values, whereas NaNO3 and CaCl2 have shown different behavior than other extracting agents for all studied trace elements. The speciation of extracted trace elements in solutions indicated that in the CaCl2, NaNO3, NH4NO3, and MgCl2 extracting agents most extracted Cd, Co, Ni, Zn, and part of Cu were as free ions and may be re-adsorbed on soils, leading to lower extractability, whereas, in the case of HNO3 extracting agent, the likelihood of re-adsorption of trace elements may be little. The results of speciation of trace elements using NH4OAc, DTPA, and EDTA extracting agents showed that Me-(Acetate)3−, Me-(Acetate)2(aq), Me(DTPA)3−, Me(EDTA)2−, and MeH(EDTA)− complexes dominated in solutions indicating that the extracted trace elements may not be re-adsorbed on soils, leading to higher extractability. The results of this study are useful for short and long-term evaluations of trace elements mobility and further environmental impacts.

Calibration standard samples for multi-element analysis of silicate rocks using inductively coupled plasma — mass spectrometry with laser ablation

A comparison of different standard samples — artificial glass SRM-612 (Standard Reference Material) and standard samples of natural composition SG-1A, SG-3, ST-1A and SGD-1A — used for external calibration in the elemental analysis of silicate rocks in the form of fused glasses by inductively coupled plasma mass spectrometry and laser ablation (LA-ICP-MS) is carried out with a goal of selecting the most suitable samples for plotting calibration dependence upon determination of the major and trace elements when using LA-ICP-MS for routine analysis. The results showed that the error of determination for both major and trace elements is lower (compared to SRM-612) when external calibration is carried out using the reference materials of natural composition with Si and Fe contents close to those in the analyzed samples. The use of internal standards in both cases decreases the systematic error attributed to the drift of LA parameters and different ablation yields. The correctness of the determination of 28 elements is proved in comparison of the results of the analysis of four standard samples with the reference values. The obtained results are used to select calibration standards for LA-ICP-MS analysis of the samples of unknown composition. The results of analysis of six samples of unknown composition match to the error limit the results of X-ray fluorescence analysis (major elements) and ICP-MS (trace elements in solutions). Refining of the content of trace elements in the previously certified reference materials allows them to be used for calibration in routine analysis of geological rocks. The developed LA-ISP-MS technique is a rapid method for determination of a wide range of elements, in particular rare earth elements, in silicate rocks and can be used for routine analysis without additional sample preparation after X-ray fluorescence analysis.

The potential role of aluminium hydroxysulphates in the removal of contaminants in acid mine drainage

Sorption of trace elements onto poorly-crystalline Al-hydroxysulphate minerals from acid mine drainage (AMD) has received less attention compared to similar Fe(III)-phases because the former are less abundant in many mine drainage environments. In addition, Al-hydroxysulphates precipitate at a higher pH, so their sorption characteristics could be masked or less significant after sorption of trace elements to Fe minerals, which form at lower pH. In this study, oxidation and titration experiments were conducted with Fe(II)-rich AMD solutions under atmospheric and anoxic conditions to elucidate, individually, the sorption capacity of trace elements in solution by Fe and Al-hydroxysulphates. Under atmospheric conditions, precipitation of Fe(III) as schwertmannite, led to total removal of Fe, As, Cr and Pb in solution and 50% of Al. Subsequently, contaminant-depleted solution began to be controlled by precipitation of basaluminite, which acted as an effective sink for the remaining Al, Cu and Si. On the contrary, under anoxic conditions, neutralisation of Fe(II)-rich solutions led first to the basaluminite precipitation, keeping all Fe available in solution and unveiling a heretofore unknown affinity for As and Cr. Basaluminite retains 60% of As in solution compared to 100% removal of As by schwertmannite. However, the sorption capacity of basaluminite is even more significant than that of Fe-phases, considering that Al concentrations in solution were much lower than those of Fe. These findings give new insights into the processes controlling contaminant mobility in anoxic environments (e.g., the bottom of AMD-affected water reservoirs) and pose new opportunities for treatment strategies.

Analysis of lanthanides and actinides in sea sediments from the Gulf of Tehuantepec

Seawater contains trace elements in solution, such as lanthanides and uranium, which can act as natural tracers when they flocculate to form the sediments of the seabed. Uranium is a special case because it is a radioactive element with isotopic ratio close to 1.14 (234U/238U) in sea water. Uranium is also present in all fractions of sediments, although the isotopic ratio in each fraction takes a specific value depending on its origin and surrounding environment. This work has been conducted in order to analyze lanthanides and uranium in a core of sea sediments. It is focused on separating the fractions forming the layers along the depth profile of the core sample so as to determine the 234U/238U activity ratios in fractions of organic matter, aquatic life skeletons and dissolved minerals. The Neutron Activation Analysis showed the presence of U, Lu, Hf, Eu, Ce and Yb ranging up to 50 ppm while alpha spectrometry gave a series of 234U/238U activity ratios which are discussed on the basis of statistical analysis.

Mobility of major-, minor- and trace elements in solutions of a planosolic soil: Distribution and controlling factors

Subsurface waters circulating in an unpolluted soil of a planosolic horizon (Massif Central, France) were studied in order to determine their physico-chemical characteristics. Three water sampling sites were chosen along a toposequence. For each site, two piezometers were placed above and in the gravelly and concretion-rich horizon (Fe- and Mn- oxyhydroxides). Concentrations of major-, minor- (cations, anions, Fe, Mn, P and Si) and trace elements (Al, Ba, Cd, Co, Cr, Cu, Ni, Pb, Rb, Sr, Zn and U) were monitored on bulk and filtered water (0.45 μm) to study both the particulate and the dissolved components, from 2004 to 2006, during the soil saturation period (i.e., from November to May). Chemical characteristics of soil solutions provide evidence for various chemical water compositions and for temporal variations of water quality, revealing that the hydrodynamic and chemical reactivity in the solution is different for the three sites. Calculations of pe values indicate a range of redox state of the soil solutions. The pe ranges are different for each piezometer but correspond to anoxic solution. For all piezometers, distribution between the dissolved and the particulate fraction and correlations between the various elements in the soil solutions indicate that: (i) Al and Fe show similar behaviour, (ii) Al is mainly present as oxyhydroxides and (iii) some trace metals are mainly associated with particles which have a mixed nature. The impact of a concretion-rich horizon is noticed both on the nature of particles and on the speciation of trace metals and could be explained by the hydrodynamic and chemical reactivity of the circulating solution. Very few correlations exist between elements in the dissolved phase.

Healing clays: Mineralogical and geochemical constraints on the preparation of clay–water suspension (“argillic water”)

Clays have been long taken internally due to their sorption effects and the mechanical shielding developed by sheet morphologies. The purpose of this paper is the modelling of the mentioned traditional application in terms of chemical and mineralogical budget towards the body. Four polymineralic clays potentially suitable for therapeutic use were analysed for their mineralogical and geochemical composition. Quartz is always present, as well as feldspars, whereas carbonates are more variable (from trace levels, to about 40%). The clay mineralogy is characterised by mixed layers illite–smectite, kaolinite and illite. Most chemical elements show little anomalies compared to average shale [Turekian, K.K., Wedephol, K.H., 1961. Distribution of the elements in some major units of the earth's crust. Geological Society of America Bulletin, 72, 175–192], excluding Ca that is enriched according to the carbonate occurrence. Another geochemical feature is the depletion of more electronegative elements, among which very hazardous elements may be found. For the preparation of “argillic water”, the clays were dispersed in water and three suspensions were prepared to test the effect of settling time (5 min, 1 h, and 24 h). After the settling, the supernatant was centrifuged to analyse the solution and the particulate. The grinding of clays (a common practice for industrial uses) sensibly reduce the mineralogical selectivity of settling, nevertheless, quartz and feldspars are depleted during settling and phyllosilicates are enriched or fluctuate when the starting value is high; the carbonate content increases or decrease within a narrow interval. The grinding procedure minimises the different behaviour of clay minerals dispersed in water because the clay assemblage of suspended particulate does not show significant trends; only illite shows a slightly decrease. The solute composition is dominated by Na > Si > Ca > K > Mg. The comparison of the 4 clays indicates that the sample richest in mixed layers shows the highest content of many trace elements in solution. The variations of solution chemistry indicate that the less soluble elements decrease with the time of settling (e.g. Fe, Al, Mn): the elements hosted in organic matter or sulphides and soluble in oxidative media, increase with time (V, Mo, Sb, As). Many other elements are rather constant or at very low concentrations. The occurrence of sorptive minerals tends to hide these trends mainly during the first hour of settling. The chemical input to the body was calculated adding the amount of element in solution to the extractable amount from the digestion of particulates. The latter is based on the simulated digestion of clays taken from the literature. A critical point is the definition of a threshold that discriminates between useful and excessive ingestion of chemical elements. Since no reference models are available, the limit for drinking water was used. Considering that adults drink 2 l of water, the maximum daily dose for water was transformed into the amount of each chemical element considered by the law and compared with the amount available from the preparation of “argillic water”. Based on these results, the settling of clays can be tuned in order to emphasise the desired composition or to minimise side effects.

A-type granites of crustal origin ultimately result from open-system fenitization-type reactions in an extensional environment

The origin of A-type granites and rhyolites are ultimately relatable to mantle-derived melts and fluids in a zone undergoing extension. The basaltic magmas are accompanied by an alkaline fluid phase, dominantly H 2O + CO 2, which will induce alkali metasomatism of the granulitic crust above. The distinctive mineralogy and geochemistry are thus a direct result of the tectonic environment of formation. Metaluminous and peralkaline granites are magmatic compositions that typically contain evidence of crust and mantle in their genetic baggage, but peraluminous A-type granites may well be caused by efficient loss of alkalis during epizonal degassing. A-type granites and rhyolites are members of a vast family of rift-related magmas that include those of syenitic, nepheline syenitic and carbonatitic character. The fluid phase at work is alkaline. It can carry a host of trace elements in solution, in particular the high-field-strength elements and the rare earths. It can fenitize and fertilize a refractory lower crust, and prepare the precursor for near-complete melting. Some examples of A-type granitic magma do arise by efficient fractional crystallization of a mantle-derived basaltic magma, with or without accompanying assimilation, but many arise by partial or complete melting of an alkali-metasomatized crust.

Removal of trace elements from landfill leachate by calcite precipitation

Spontaneous precipitation of secondary calcite (CaCO 3) has been observed in 25 samples of landfill leachate-polluted stream waters. During the 6-month precipitation experiment, the formation of calcite acts as a principal trace-element scavenging process. The concentrations of Fe, Sr, Ba and Mn and other trace elements in solution significantly decreased as calcite formed during the experiments. The PHREEQC-2 geochemical code indicated high supersaturation of the initial leachate-polluted waters with respect to calcite. The chemical/mineralogical study (SEM/EDS, XRD, ICP MS) revealed that this newly formed calcite contains considerable amounts of metals and metalloids removed from solution. Such a geochemical process can be considered to be important for spontaneous decontamination in landfill-affected environments (stream sediments, soils) or landfill technical facilities (settling basins). This removal takes place especially during dry periods with low rain precipitation, when the landfill waters exhibit both higher alkalinity and higher trace element concentrations.

The Radium Institute and the Russian Academy of Sciences

The contribution of the Radium Institute to the establishment and development of Russian atomic science and technology is examined in a historical review based on the scientific and organizational, relations with the Russian Academy of Sciences. The basic scientific achievements obtained at the Institute when it was part of the Academy system are noted: creation of the radium industry in Russia, discovery of the spontaneous fission of uranium, construction and startup of the first cyclotron in Europe, determination of the laws govering the distribution of trace elements in solution (gas)-solid phase systems development and adoption of the first Soviet technology for obtaining weapons plutonium. The integrated nature of the research, characteristic for the Institute from the moment the Institute wa formed to the present is shown. Scientific schools in nuclear physics, radiochemistry, and radiogeochemistry were established at the Institute, and are still operating, in connection with the work of outstanding Russian scientists.

MAJOR AND TRACE ELEMENTS GEOCHEMISTRY IN THE GROUND WATERS OF A VOLCANIC AREA: MOUNT ETNA (SICILY, ITALY)

Thirty-five ground-water samples have been collected from wells, springs and drainage galleries on Mt Etna volcano for the determination of major, minor and trace elements in solution. Attention has been focused in particular on dissolved minor and trace elements, for most of which no data were available in the studied area. In general, dissolution of solids into Etna's ground waters follows from strong interaction between water of meteoric origin, CO 2 gas of magmatic origin and the volcanic rocks of the aquifers. However, the R-mode analysis allowed to distinguish several sources of solutes: Al, Co, Ni, Fe, Si, As would derive mainly from alteration of the volcanic rocks of Etna; SO 4 =, K, Na, V, Sr, Mo, Cr and calculated p(CO 2) would instead indicate a major contribution of volcanic gases (mostly CO 2 and SO 2); and TDS, HCO 3 =, Li Mg, B and Cl − would indicate a derivation from both these sources. Se, Hg, Cu and Mn would derive from hydrothermal fluids, and Ca would derive both from this latter contribution and from rock alteration. The comparison between trace elements abundance in Etna's ground waters and that in the ground waters of other areas of Italy showed that, in general, Etna's waters, like other volcanic ground waters, are enriched in Li, Mn, Si, V, As and Mo. Furthermore, in the areas of Mt Etna where the contribution of volcanic gas to the aquifers is greatest, ground waters are also enriched in B, Se, Co, Hg, Al, Fe and Ni. The obtained results show clearly that, in active volcanic areas, many dissolved elements can attain levels that can be appreciably different from those indicated by WHO for drinking water. Therefore, the local geological factors which can influence the geochemical behavior of these elements in solution should be taken into account when establishing national standards for drinking-water quality. In consideration of the local natural background values, concentrations of dissolved elements that differ from the guideline values should be accepted in areas with peculiar geological characteristics, provided that the elements under consideration do not have a direct influence on health. © 1998 Elsevier Science Ltd. All rights reserved

Changes in trace metal species and other components of the rhizosphere during growth of radish

ABSTRACTChanges in the properties of soil solution in the rhizosphere of developing radish plants were investigated. Variations in these properties were expected to affect the distribution and speciation of metals in the soil and soil solution. Applications of essential nutrients were linked to plant transpiration rates and prevented excess addition of nutrient ions, so that subtle changes in soil solution composition would not be obscured. Soil solution pH, the concentration of dissolved organic carbon (DOC) and the concentrations of major and trace elements in solution were found to vary over time. Strict control of fertilizer additions led to the maintenance of a relatively low ionic strength in the soil solution, and under such conditions trace metal solubility appeared to be highy influenced by the concentration of DOC. A chemical speciation analysis was performed which showed that, while dissolved Cd and Zn were largely uncomplexed in unplanted soil, Cd and Zn in the rhizosphere existed mainly as complexed forms. It is hypothesized that this is partly a result of Ca‐metal‐ligand equilibrium in solution, with higher Ca concentrations in unplanted soil leading to more of the Cd and Zn in solution existing in the uncomplexed state. Changes in the concentrations of uncomplexed Cd and Zn with time gave the best correlations with changes in plant uptake of these metals over time, supporting the hypothesis that plants mainly absorb the free metal ion from soil solution.

Interference Effects and Their Control in ICP-MS Analysis of Serum and Saline Solutions

Advances in analytical technology have led to the development of a variety of very sensitive techniques for determination of very low levels of trace elements in biological and/or environmental matrices. However, the improvement in equipment and data handling has not been accompanied, in general, by an equivalent attention to the quality of results. In this framework, inductively coupled plasma-mass spectrometry offers extremely high detection power for the determination of a wide range of elements. The analysis of samples with a complex matrix is nevertheless a very challenging task. The determination of trace elements in solutions containing high salt concentrations, e.g., human serum (9 g/liter NaCl) and saline solution with dissolved solid (5 g/liter NaCl) was studied. The use of reference materials and internal standardization allows the determination by ICP-MS of Br, Ca, Mg, Rb, Sr, and Zn in serum to be optimized. The signal suppression in the presence of NaCl depends on the ionization potential and mass of the element considered. Cluster analysis is applied to a matrix of data of signal suppression of 25 elements under different conditions. Four groups of elements with the same behavior were identified and for each group a suitable internal standard was chosen. The use of three internal standards instead of a single one improves significantly the experimental accuracy and precision in the analysis of saline solutions.

Chemical processes at the sediment-water interface

In natural waters, the sediment-water interface is the site where gradients in physical, chemical and biological properties are the greatest. Both chemical and microbiological transformation processes are responsible for cycling elements between water and sediments. This paper discusses the various chemical transformations that take place during early diagenesis in sediments, and which are fueled by supply rates of organic carbon and electron acceptors. In particular, our current knowledge of the cycling of the electron acceptors O, N, Mn, Fe and S is assessed, and the important role of transport reactions is described. The elemental fluxes across the sediment-water interface can be described from first principles only if the coupling of physical, chemical and biological processes is better understood. Large gradients in chemical potentials of many chemical species across this interface often lead to steep gradients in proton and electron activities. The redox sequence commonly observed in time and space also leads to changes in the partitioning of solutes between carrier and solution phases. Such processes can cause rapid back-diffusion of released species to the overlying water column or their removal onto secondary carrier phases within the sediments. Physical transport systems such as resuspension or bioturbation of particles control the physical boundary conditions for chemical reactions immediately above or below the sediment-water interface. Because of the complex coupling of the different chemical, physical and biological processes, chemical reactions within this region must be considered an integral part of a three-dimensional network of interactions. Hence, the apparent coexistence of chemical species considered ‘incompatible’ by thermodynamic models can be a consequence of the three-dimensional nature of redox gradients. The microbiological, chemical and physical interactions of dissolved, colloidal and particulate organic carbon, and iron and manganese oxides play a crucial role in the early diagenetic reactions at the sediment-water interface. Their effects on diagenetic reactions, and on trace elements in solution and adsorbed to particles, are discussed. Furthermore, we emphasize the way in which hydrodynamics can control elemental fluxes in environments with high carbon rain rates.

Laser Induced Photoacoustic Spectrometry with Single Particle Sample

LIPAS (laser induced photoacoustic spectrometry) has been adopted for quantitative analysis of a single particle.To avoid the effects of the sample form (such as particle or coarse powder) upon the intensities of strong light absorption and strong light scattering, analysis using a single particle was carried out instead of diluting with optically transparent material. A solid adsorbent particle such as XAD-2 was used, on which trace elements in solutions were adsorbed in the form of metal-oxine (oxine=8-quinolinol) complexes. Here, 0.02-20ng zinc adsorbed on one XAD-2 particle could be detected quantitatively. Moreover, combination of LIPAS with both a single particle adsorbent and enrichment technique was found to be an excellent method for quantitative analysis for trace materials.

Microbial Responses to Trace Elements and Nutrients in the St. Lawrence River

Abstract Over 100 surface sediment samples from Lac St. Louis (St. Lawrence River) were examined for various microbial physiological types and densities. These organisms were correlated to the concent rat ions of trace elements (Ni, Co, Cr, V, Cu, Pb, Zn, As, Fe, Mn and Ti) and nutrients (P and organic matter). Results indicated a relationship between bacterial densities and trace element concentrations. Data also suggested there was an apparent indication of bacterial inhibit ion due to toxic substances in the lake sediment. Generally, high and low bacterial density zones existed in the sediment with low bacterial density zones being associated with high concentrations of trace elements. Because of the relationships and the distribution of trace elements and organic matter, the lake bottom exhibited a heterogeneous nature. The availability of trace elements in the surface sediments was assessed by determination of chemical species of the trace elements in solutions obtained by elutriation of the sediment with distilled water. Data and methodology are presented.

Characterization of a Lignite Ash from the METC Gasifier III. Correlations of Leaching Behavior and Mineralogy

AbstractLignite gasification ash from the Morgantown Energy Technology Center (METC) gasifier was subiected to two short-term leaching treatments. The cnncentrations of regulated elements in the EPA EP procedure leachate from the bulk METC ash did not exceed the “EP Trigger Limits.” A modification of this procedure that uses a basic synthetic groundwater instead of the acid EP extractant was also performed on the bulk ash and its eleven size fractions. Water equilibria modeling was used to explain the concentrations of major elements in solution. Corcentrations of minor and trace elements in solution after leaching with synthetic groundwater were also below “EP Trigger Limits.”

Direct solution analysis using an arc source incorporating two plasmas rotating in a graphite tube

As a continuation of earlier work on arc sources for the spectrochemical analysis of powdered samples, a source appropriate for multi-element analysis of trace elements in solution has been developed. The nebulized solution to be analysed is introduced into a horizontal graphite tube in the gap between two plasmas rotating in a magnetic field. Both water and ethanol have been used as solvents and the effect of lithium additions on the detection limits for certain elements has been studied. This source provides advantageous conditions for the determination of trace elements present at very low concentrations. Source parameters investigated include a study of the magnetically induced rotation of the plasmas by high speed cine photography, and the temperature distribution within the tube. Both aqueous and ethanol solutions were used and the effect of lithium additions was measured.

A low-wattage microwave torch discharge for emission spectrometry of trace elements in solutions

A low-wattage microwave torch discharge for emission spectrometry of trace elements in solutions

Emission spectrometry of solutions with a low-wattage microwave discharge

A low-wattage microwave discharge for the detection of trace elements in solution has been investigated. Aqueous sample solutions were nebulized by an ultrasonic nebulizer, and the solvent was removed by a desolvation facility before introduction of the aerosol into the discharge. Pronounced inter-element effects, both enhancements and suppressions of the emission, were found. The rotational and excitation temperatures of the discharge were determined, and the former was found to be much lower than the latter.