Elements concentration analysis in groundwater from the North Serra Geral aquifer in Santa Helena-Brazil using SR-TXRF spectrometer

2012 ◽  
Vol 66 (5) ◽  
pp. 1029-1035 ◽  
Author(s):  
Gisele C. Justen ◽  
Fernando R. Espinoza-Quiñones ◽  
Aparecido Nivaldo Módenes ◽  
Rosangela Bergamasco
Keyword(s):  
Major Element ◽  
Monitoring Program ◽  
Major Elements ◽  
Regional Level ◽  
X Ray ◽  
The North ◽  
Tube Wells ◽  
The Mean ◽  
Mean Concentration ◽  
Groundwater Composition

In this work the analysis of elements concentration in groundwater was performed using the synchrotron radiation total-reflection X-ray fluorescence (SR-TXRF) technique. A set of nine tube-wells with serious risk of contamination was chosen to monitor the mean concentration of elements in groundwater from the North Serra Geral aquifer in Santa Helena, Brazil, during 1 year. Element concentrations were determined applying a SR-TXRF methodology. The accuracy of SR-TXRF technique was validated by analysis of a certified reference material. As the groundwater composition in the North Serra Geral aquifer showed heterogeneity in the spatial distribution of eight major elements, a hierarchical clustering to the data was performed. By a similarity in their compositions, two of the nine wells were grouped in a first cluster, while the other seven were grouped in a second cluster. Calcium was the major element in all wells, with higher Ca concentration in the second cluster than in the first cluster. However, concentrations of Ti, V, Cr in the first cluster are slightly higher than those in the second cluster. The findings of this study within a monitoring program of tube-wells could provide a useful assessment of controls over groundwater composition and support management at regional level.

scholarly journals Statistically Coherent Calibration of X-Ray Fluorescence Spectrometry for Major Elements in Rocks and Minerals

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Surendra P. Verma ◽  
Sanjeet K. Verma ◽  
M. Abdelaly Rivera-Gómez ◽  
Darío Torres-Sánchez ◽  
Lorena Díaz-González ◽  
...  
Keyword(s):  
Linear Regression ◽  
Major Elements ◽  
Chemical Data ◽  
Confidence Limits ◽  
Total Uncertainty ◽  
X Ray ◽  
Analytical Instruments ◽  
Before And After ◽  
The Mean ◽  
Mean Concentration

We applied both the ordinary linear regression (OLR) and the new uncertainty weighted linear regression (UWLR) models for the calibration and comparison of a XRF machine through 59 geochemical reference materials (GRMs) and a procedure blank sample. The mean concentration and uncertainty data for the GRMs used for the calibrations (Supplementary Materials) (available here) filewere achieved from an up-to-date compilation of chemical data and their processing from well-known discordancy and significance tests. The drift-corrected XRF intensity and its uncertainty were determined from mostly duplicate pressed powder pellets. The comparison of the OLR (linear correlation coefficient r∼0.9523–0.9964 and 0.9771–0.9999, respectively, for before and after matrix correction) and UWLR models (r∼0.9772–0.9976 and 0.9970–0.9999, respectively) clearly showed that the latter with generally higher values of r is preferable for routine calibrations of analytical procedures. Both calibrations were successfully applied to rock matrices, and the results were generally consistent with those obtained in other laboratories although the UWLR model showed mostly narrower confidence limits of the mean (slope and intercept) or lower uncertainties than the OLR. Similar sensitivity (∼2.69–46.17 kc·s−1·%−1 for the OLR and ∼2.78–59.69 kc·s−1·%−1 for the UWLR) also indicated that the UWLR could advantageously replace the OLR model. Another novel aspect is that the total uncertainty can be reported for individual chemical data. If the analytical instruments were routinely calibrated from the UWLR model, this action would make the science of geochemistry more quantitative than at present.

scholarly journals Nutrient output from rural areas on the example of two catchments Skuterud and Zagożdżonka

2011 ◽  
Vol 43 (1) ◽  
pp. 71-85 ◽  
Author(s):  
Karolina Sawa ◽  
Leszek Hejduk ◽  
Johannes Deelstra ◽  
Lillian Øygarden
Keyword(s):  
Rural Areas ◽  
Management Practices ◽  
Monitoring Program ◽  
Average Concentration ◽  
General Description ◽  
Nutrient Runoff ◽  
Nitrogen Concentrations ◽  
The Mean ◽  
Summer Time ◽  
Mean Concentration

Nutrient output from rural areas on the example of two catchments Skuterud and Zagożdżonka In this paper, two rural catchment - the Zagożdżonka catchment in Poland and the Skuterud catchment in Aas, Akershus county in Norway are compared. In addition to the general description, more in particular information, runoff, N-NO3 load, P-PO4 load, total phosphorus and total nitrogen concentrations in streams are compared. The data compared are from 1993 to 1995 in Zagożdżonka catchment and from 1994-1996 from Skuterud catchment. The average concentration of N-NO3 in Zagożdżonka River in the period was 0.85 mg·l-1 and the mean concentration of P-PO4 was 0.13 mg·l-1. In the stream in Skuterud catchment the average concentration of N-NO3 was 4.95 mg·l-1 and the mean concentration of P-PO4 was 0.04 mg·l-1. For both catchments the same data were also compared for the 2008. In Skuterud catchment the highest concentration of nutrients occurred in November, March and April, which was connected to the higher runoff from agricultural areas during the snowmelt period. In Zagożdżonka catchment the highest concentration of nutrients was noted in March, April and in summer time, which was connected to periods with high amounts of precipitation. Comparison of the two rural catchments showed many differences in applied measurement methods for water sampling, water measurement, discharge measurement, runoff amounts and management practices, which had an effect on results of monitoring program. The compared data can be useful to predict the development of future environmental conditions for example water quality. It can also be useful for predict how nutrient runoff will be in future. What is more the different conditions for runoff in Skuterud and Zagożdżonka then different measures are needed.

scholarly journals Foliar Micromorphology and Histochemical Localization of Specific Metabolites in the Leaves of Celosia argentea L.

2019 ◽  
Vol 47 (4) ◽  
pp. 1128-1135
Author(s):  
Oluwafunmilayo Dorcas ADEGBAJU ◽  
Gloria Aderonke OTUNOLA ◽  
Anthony Jide AFOLAYAN
Keyword(s):  
Glandular Trichomes ◽  
Major Elements ◽  
Digital Object Identifier ◽  
Abaxial Surface ◽  
X Ray ◽  
Sodium Calcium ◽  
Celosia Argentea ◽  
Histochemical Tests ◽  
The Mean ◽  
Information Database

Celosia argentea is an essential vegetable that is cultivated in the western part of Africa. This species has a growing reputation for its role in alleviating nutritional challenges and has found great application as herb of therapeutic importance in many regions of the world. This study investigated the foliar micromorphology and the histochemistry of Celosia argentea. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrometry and staining agents were used to evaluate the micromorphology of the plant. The result revealed sunken amphistomatic stomata distribution on both surfaces of the leaf. Anomocytic and anisocytic stomata complexes were also observed on both epidermal surfaces. A definitive protuberance was observed on the polar end of the adaxial stomata. Stomata apparatus was ellipsoidal with a mean length of 19.60 ± 0.56 µm, while the mean stomata densities on the adaxial and abaxial surfaces were 83.5 ± 2.12 mm‑2 and 194.18 ± 3.70 mm‑2 respectively. Trichomes (with a length of 100.94 ± 9.44 µm) were sparsely distributed on both surfaces; glandular trichomes were observed only on the abaxial surface. The EDX spectrometry revealed the presence of iron, oxygen, sodium, calcium, potassium and sulphur as the major elements on the leaf, while histochemical tests revealed the presence of polyphenols, starch and lipids. Our results could be used to support and validate the information database on the anatomy of Celosia argentea.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

Fourfold alkyl wrapping of a copper(II) porphyrin thwarts macrocycle π–π stacking in a compact supramolecular package

2020 ◽  
Vol 76 (7) ◽  
pp. 647-654
Author(s):  
Phattananawee Nalaoh ◽  
Sareeya Bureekaew ◽  
Vinich Promarak ◽  
Jonathan S. Lindsey
Keyword(s):  
Supramolecular Assembly ◽  
Free Base ◽  
X Ray Diffraction ◽  
Aryl Group ◽  
X Ray ◽  
The North ◽  
Π Stacking ◽  
Solid Crystal ◽  
The Mean ◽  
Atom Position

Porphyrins are valuable constituents in optoelectronic, catalytic, and other applications, yet control of intermolecular π–π stacking is invariably essential to attain the desired properties. Superstructures built onto the porphyrin, often via meso-aryl groups, can afford facial encumbrance that suppresses π–π stacking, although some molecular designs have provided insufficient facial coverage and many have entailed cumbersome syntheses. In this study, a copper(II) porphyrin bearing four meso substituents, namely, {10,20-bis[2,6-bis(octyloxy)phenyl]-5,15-dibromoporphinato}copper(II), [Cu(C64H82Br2N4O4)], was prepared by metalation of the corresponding free-base porphyrin and was characterized by single-crystal X-ray diffraction. The crystal structure reveals a dihedral angle of 111.1 (2)° for the plane of the meso-aryl group relative to the plane of the porphyrin, with both aryl groups tilted in the same direction. Each of the four octyloxy groups exhibits a gauche conformation for the –OCH2CH2– unit but is extended with four or five anti (–CH2CH2–/H) conformations thereafter, causing each octyl group to span the dimension of the macrocycle. In a global frame of reference where the two Br atoms define the north/south poles and the two aryl groups are at antipodes on the equator, two octyl groups of one aryl unit project over the northern hemisphere (covering pyrroles A and B), whereas those of the other aryl unit project over the southern hemisphere (covering pyrroles C and D). Together, the four octyl groups ensheath the two faces of the porphyrin in a self-wrapped assembly. The closest approach of the Cu atom to an octyl methylene C atom (position 6) is 3.5817 (18) Å, the mean separations of neighboring porphyrin planes are 8.059 (4) and 4.693 (8) Å along the a and c axes, respectively, and the center-to-center distances between the Cu atoms of neighboring porphyrins are 10.2725 (4), 12.2540 (6), and 12.7472 (6) Å along the a, b, and c axes, respectively. The Hirshfeld surface analysis and two-dimensional (2D) fingerprint plots provide information concerning contact interactions in the supramolecular assembly of the solid crystal.

An evaluation of major element heterogeneity in the mantle sources of basalts

1980 ◽  
Vol 297 (1431) ◽  
pp. 383-407 ◽  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Major Element ◽  
Major Elements ◽  
Element Abundances ◽  
Ocean Island ◽  
Basaltic Rocks ◽  
The North ◽  
Mantle Sources ◽  
Incompatible Trace Elements

Understanding the evolution of the mantle requires a knowledge of the relative variations of the major elements, trace elements and isotopes in the mantle. Most of the evidence for mantle heterogeneity is based on variations in the trace element and isotopic ratios of basaltic rocks. These ratios are presumed to reflect variations in the mantle sources. To compare major element heterogeneities with trace element and isotopic heterogeneities, it is necessary that the major element abundances in basalts also reflect variations in the mantle sources. Probably the only major element for which this is so is iron. If a basalt has only undergone fractional crystallization of olivine, then the abundance of FeO in the basalt reflects the FeO/MgO ratio of the mantle source, the degree of melting, and the pressure at which melting occurs. Relative pressures and degrees of melting can often be constrained, so that variations in the abundances of FeO can be used to obtain information about variations in the FeO/MgO ratio of the mantle sources of basalts. Comparison of FeO contents with trace element and isotopic contents of basalts shows some striking correlations and leads to the following conclusions. 1. Parental magmas for Kilauean basalts from Hawaii may be related by different degrees of melting of a homogeneous, garnet-bearing source. 2. Mid-ocean ridge basalts from the North Atlantic show a negative correlation of La/Sm with FeO, suggesting that the sources that are most enriched in incompatible trace elements are most depleted in FeO relative to MgO, and are probably also depleted in the other components of basalt. This correlation does not apply to the entire suboceanic mantle. 3. A comparison of tholeiites from near the Azores and from Hawaii shows that sources with similar Nd and Sr isotope ratios may have undergone distinctly different histories in the development of their major and trace element abundances. 4. Ocean island tholeiites tend to be more enriched in FeO than ocean floor tholeiites. Either the ocean island sources have greater FeO/MgO ratios, or melting begins at significantly greater pressures beneath ocean islands than beneath ocean ridges. 5. Major element variations in the mantle are controlled mainly by tectonics and the addition or removal of silicate melts. Trace element variations, however, may be controlled by the addition or removal of fluids as well. Thus major elements, trace elements and isotopes may each give a different perspective important to the understanding of the evolution of the mantle.

Quantitative determination of analcime in pumice samples by X-ray diffraction

1978 ◽  
Vol 42 (321) ◽  
pp. 103-106 ◽  
Author(s):  
R. J. Parker
Keyword(s):  
Major Element ◽  
Compositional Data ◽  
Internal Standard ◽  
Diffraction Method ◽  
Calibration Line ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Mean ◽  
Compositional Variations

SummaryA quantitative X-ray diffraction method has been successfully applied to the determination of analcime in pumice rock samples. A calibration line was constructed from spiked pumice standards (range: 0 to 42%) and the mean relative error of the standards on the calibration line was < 0·6%. The major-element compositions of the samples and standards were available, and this allowed the total mass absorption coefficients to be calculated. The latter were then used to correct the sample and standard intensities for absorption effects resulting from compositional variations. When compositional data already exist, the calculation of the total absorption coefficient provides a rapid and accurate alternative to direct measurement, or to the use of an internal standard.

scholarly journals The assessment of hepatic mineral composition in sheep, cattle, chicken, and fish in Erbil City, Kurdistan Region-Iraq

2021 ◽  
pp. 46-55
Author(s):  
Abdulqader Ahmed Hussein
Keyword(s):  
Dry Weight ◽  
High Concentration ◽  
Toxic Level ◽  
Mean Values ◽  
X Ray ◽  
The Mean ◽  
Mineral Concentrations ◽  
Fluorescence Spectrometer ◽  
The City ◽  
Mean Concentration

Liver mineral concentrations of 232 samples from slaughtered animals, including  lamb, yearling, sheep, and cattle, checkin, and fish were detrmined, using X-ray fluorescence spectrometer, to provide data regarding to the liver mineral concentrations (mg/kg dry weight). The mean liver Zn and Co liver conentrations of lambs (286, 1.9), yearling (233, 1.7), sheep (254, 1.8), and cattle (276, 1.8) in majority samples were adequate, while liver Pb concentrations of mentioned animals (45.3, 48.1, 46.4, 39.6) mg/kg respectively were high and exceeded toxic levels. In checkin, the mean liver Cu, Zn, and Co were also adequate, with the mean values of (26.4), (298.8), and (1.8) mg/kg respectively. Though, the mean liver Fe concentration (2257.0 mg/kg) was high, and liver Pb concentration (6.2 mg/kg) was reched toxic level. In fish, for majority liver samples, the mean concentration of Cu (191.8), Fe (6800.0), Zn (202.8), Co (3.3), Pb (8.6), and Ni (6.3) were high and toxic. In conclusion, liver Pb (and Ni only in fish) concentration in all studied animals for the majority of examined sample were higher than normal and toxic. Wherese, other studied minerals in majority of liver samples were adequate. Therefore, it can be concluded that there are problems on animal and human health (due to high concentration of Pb and Ni) would be raised at present from the consumption of ovine, bovine, checkin, and fish slaughtered from the city of Erbil.

Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

1983 ◽  
Vol 41 ◽  
pp. 446-447
Author(s):  
William F. Tivol ◽  
Murray Vernon King ◽  
D. F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Heavy Atom ◽  
Isomorphous Substitution ◽  
X Ray Diffraction ◽  
Salt Solutions ◽  
X Ray ◽  
Isomorphous Replacement ◽  
Structure Factors ◽  
Diffraction Structure ◽  
The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

Instant 99mTc-Labelled Glucoheptonate Kit for Kidney Imaging

1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha
Keyword(s):  
Sodium Hydroxide Solution ◽  
Normal Subjects ◽  
Organ Distribution ◽  
Stable Complex ◽  
Scintillation Camera ◽  
Ph Adjustment ◽  
The Mean ◽  
The Stability ◽  
Kidney Imaging ◽  
Mean Concentration

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.

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