Synchrotron Radiation Total Reflection X-ray Research Articles

Topsoil pollution in highway medians in the State of São Paulo (Brazil): determination of potentially toxic elements using synchrotron radiation total reflection X-ray fluorescence.

The presence of metals in vehicle emissions is due to several factors, such as the composition of fuels and lubricating oils, the wear of engine components, and their use in catalytic converters. It is known that the soil near highways is greatly affected by heavy vehicle traffic, since the use of highways is of fundamental importance for the flow of goods and public transport, especially in Brazil, street transport being the main form of transport in the country. Considering the scenario described, the main objective of this study was to monitor the concentration of potentially toxic elements in surface soils located on the medians of the main access highways in the city of Campinas (SP-Brazil) and classify the soils through geoaccumulation index. Using SR-TXRF it was possible to detect and determine the concentrations of 5 elements of toxic-environmental interest (Cr, Ni, Cu, Zn, and Pb) and 11 natural soil composition elements (Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Rb, and Sr). To evaluate the influence of highway distance on elementary concentrations, ANOVA and Tukey statistical tests were applied. Nickel, Cu, and Zn showed a decrease in their concentrations moving away from the highway, indicating their relation with vehicular emissions. Applying principal components analysis (PCA), it was possible to identify four groups of the quantified elements: those mainly related to the soil itself, those produced by traffic of automotive vehicles, and those emitted by industrial activities.

Multielement analysis of plant extracts with potential use in the treatment of peptic ulcers by synchrotron radiation total reflection X-ray fluorescence.

Some plants popularly employed for the treatment of peptic ulcers have proved to be attractive sources of new drugs. Despite extensive research, the pharmacological and toxicological potentials of these plants are not fully understood. In this context, the aim of this work was to analyze the multielemental composition of the methanolic extracts of three of those plants, Alchornea glandulosa (AG), Davilla elliptica (DE) and Davilla nitida (DN), with the intention of contributing to the understanding of the mechanisms of action of these extracts. For this purpose, we used the analytical technique of total reflection X-ray fluorescence (TXRF) by synchrotron radiation at the Brazilian Synchrotron Light Source (LNLS/CNPEM). It was possible to determine the concentrations of the elements: P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb and Br in all of the samples. Selenium (Se) was detected only in the DN extract. An inverse relationship between the concentrations of elements with proven effectiveness and the gastroprotective activity of extracts considering induction protocols with ethanol and non-steroidal anti-inflammatory drugs (NSAIDs) was obtained. This data suggests that the function of the extract is not only associated with providing the elements for restoring the gastric mucosa but that it also promotes the displacement of these elements from other parts of the mucosa to the damaged area. Correlations between the concentrations of the elements were also obtained. In the DE extract, which is the most effective extract for both induction protocols, the obtained correlations were above 70% among almost all of the elements, and no anticorrelations were found. For the other two extracts, in the less effective extract (AG) anticorrelations above 70% were predominantly found. Meanwhile, in the DN extract, a few high anticorrelations were found, which may explain its intermediate stage of effectiveness.

Synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) and X-ray absorption near edge structure (XANES) of fractionated air particulates collected from Jeddah, Saudi Arabia

Fractionated atmospheric aerosols with sizes ranged from 0.25μm to >16μm have been collected on silicon wafers using a 7-stage cascade impactor from the centre location of Jeddah city, Saudi Arabia during May 2015. Two fractionated sizes were selected in the present work, namely 0.5–0.25μm (PM0.5–0.25) and 2–1μm (PM2.0–1.0), because their mass concentrations were the most dominant. Fractionated atmospheric aerosols were examined under ultra-high vacuum environment with synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) and X-ray absorption near edge structure (XANES) spectroscopy techniques at the International Atomic Energy Agency (IAEA) experimental end station operating at Elettra Sincrotrone Trieste, Italy. The mass concentrations in PM2.0–1.0 were found greater than those within PM0.5–0.25 material and the mass concentration ratio of PM2.0–1.0/PM0.5–0.25 was reached to 2. The homogeneity in the spatial deposition of different elements in both PM0.5–0.25 and PM2.0–1.0 fractions was evaluated by the means of X-ray fluorescence (XRF) scanning. XANES showed us that Cr species exist mainly in the trivalent oxidation state, while for Mn the co-existence of both the divalent and trivalent oxidation states was determined. The results of the present study provide an improved understanding on the origin of Cr and Mn species in these two fractionated particulates and give an insight to their contribution to atmospheric and physicochemical processes.

Iron overload of human colon adenocarcinoma cells studied by synchrotron-based X-ray techniques.

Fast- and slow-proliferating human adenocarcinoma colorectal cells, HT-29 and HCA-7, respectively, overloaded with transferrin (Tf), Fe(III) citrate, Fe(III) chloride and Fe(II) sulfate were studied by synchrotron radiation total-reflection X-ray spectrometry (TXRF), TXRF-X-ray absorption near edge structure (TXRF-XANES), and micro-X-ray fluorescence imaging to obtain information on the intracellular storage of overloaded iron (Fe). The determined TfR1 mRNA expression for the investigated cells correlated with their proliferation rate. In all cases, the Fe XANES of cells overloaded with inorganic Fe was found to be similar to that of deliquescent Fe(III) sulfate characterized by a distorted octahedral geometry. A fitting model using a linear combination of the XANES of Tf and deliquescent Fe(III) sulfate allowed to explain the near edge structure recorded for HT-29 cells indicating that cellular overload with inorganic Fe results in a non-ferritin-like fast Fe storage. Hierarchical cluster analysis of XANES spectra recorded for Fe overloaded HT-29 and HCA-7 cells was able to distinguish between Fe treatments performed with different Fe species with a 95% hit rate, indicating clear differences in the Fe storage system. Micro-X-ray fluorescence imaging of Fe overloaded HT-29 cells revealed that Fe is primarily located in the cytosol of the cells. By characterizing the cellular Fe uptake, Fe/S content ratios were calculated based on the X-ray fluorescence signals of the analytes. These Fe/S ratios were dramatically lower for HCA-7 treated with organic Fe(III) treatments suggesting dissimilarities from the Tf-like Fe uptake.

Biomonitoring of environmental pollution using growth tree rings of Tipuana tipu: Quantification by synchrotron radiation total reflection X-ray fluorescence

Currently, many studies use the bioindicators to qualitatively and/or quantitatively measure pollution. The analyses of tree growth rings represent one such bioindicator as changes in the environment are often recorded as impressions in the wood. The main objective of the present study is to examine the growth rings of Tipuana tipu – a member of the Leguminosae family that is native to Argentina and Bolivia and was introduced in Brazil as an ornamental plant – for potentially toxic elements. T. tipu is one of the most common trees in the urban landscape of Sao Paulo city and would provide an accurate reflection of environment changes. Tree ring samples previously dated using Synchrotron Radiation Total Reflection X-ray Fluorescence were collected from strategic locations in Sao Paulo. These locations include Piracicaba (SP) that has little access and small flow traffic and the campus of the University of São Paulo. Some trace elements present concentrations higher than considered as normal in some periods. In São Paulo city, samples collected from the campus of University of São Paulo (Butantã), showed the highest toxicity, with concentrations above the tolerable limit for the elements: Cr, Cu, and Pb. For the samples collected in Piracicaba city, one sample presented highest concentrations for the majority of the elements when compared to the other four samples collected at the same place, exceeding the toxicity limits for: Cr, Ni, Cu, and Pb.

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

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.

Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vivo exposure to mercury: A study using synchrotron radiation total reflection X-ray fluorescence

In recent years, the effects of pollution on the health of humans and other vertebrates were extensively studied. However, the effects on some invertebrates are comparatively unknown. Recent studies have demonstrated that toxic metals interfere with the reproduction, development and immune defenses of some terrestrial and marine invertebrates. Some environmental conditions including pollution produce chronic and acute effects on different animal's organs and systems. In this work, we investigated changes in the concentrations of Cl, K, Ca, Fe and Zn in Rhodnius prolixus as insect model. The elements were quantified using urine and hemolymph samples collected on different days after feeding the insects with blood containing HgCl2. The synchrotron radiation total reflection X-ray fluorescence measurements were carried at the X-ray fluorescence beamline facility in Brazilian Synchrotron Light Laboratory. The observation reveals that the calcium level was higher in the hemolymph than in urine. On the other hand, the urine collected from insects treated with HgCl2 showed higher level of Cl than hemolymph samples. Ca, Fe and Zn concentrations decrease drastically in urine samples collected after 2days of HgCl2 treatment. The regulation of triatomines excretion was discussed pointing out the importance of trace elements.

Distribution of Calcium, Iron, Copper, and Zinc in Two Portions of Placenta of Teenager and Adult Women

The placenta is fundamental for fetal development. The aim of this study was to determine Ca, Fe, Cu, and Zn content in the fetal and maternal portions of the placentas of teenage and adult women. Measurement of the minerals was conducted using Synchrotron radiation total reflection X-ray fluorescence. Forty samples from the fetal portion of teenagers and adults and 40 samples from the maternal portion of teenagers and adults were analyzed. There were significant differences in the Ca and Cu concentrations of the placenta's maternal portion when compared to the fetal portion, for both teenagers and adults. There were differences in Fe and Zn concentrations only when comparing the maternal portion of placenta with the fetal portion of the adults. These results suggest important differences in mineral content based on the placental portion. No significant difference was observed between the minerals studied of the maternal portion of teenagers and adults; however, in the fetal portion, mineral concentrations were greater in adults than in teenagers. Therefore, the mineral concentration of the fetal portion of the placenta is influenced by the mother's age. If there is mineral's competition between the mother and fetus during pregnancy in adolescence due to the importance of these minerals in growth and development, then the mechanism and reason for it should be elucidated in future research. In addition, we believe that further research should be carried out on transporters of these minerals in the same portions of the placentas analyzed by our group, in teenagers and adults.

Maternal-Fetal Distribution of Calcium, Iron, Copper, and Zinc in Pregnant Teenagers and Adults

Adolescence is marked by intensive growth and development. When pregnancy occurs during this period of the mother's growth, there is an increase in her nutritional needs. The aim of this study was to determine the levels of calcium, iron, copper, and zinc in maternal plasma, the placenta, and in the cord plasma of pregnant teenagers and adults. A total of 80 sets of maternal plasma, placentas, and cord plasma (40 from teenagers and 40 from adults) were analyzed using synchrotron radiation total reflection X-ray fluorescence. The levels of calcium, copper, and zinc in the maternal and cord plasma from teenagers were not significantly different than those from adults. Iron levels in the teenagers maternal and cord plasma were higher than in the adults. All of the minerals analyzed were present at higher levels in the placentas from adults than those from teenagers. However, the low quantities of placental calcium, iron, copper, and zinc in the teenagers do not compromise the levels of these minerals in the cord plasma. Future research regarding the placental transport of these minerals is recommended to investigate the efficiency of mechanisms of transfer of these minerals in pregnant teenagers.

Water quality assessment of Toledo River and determination of metal concentrations by using SR-TXRF technique

The region of Toledo River, Parana, Brazil is characterized by intense anthropogenic activities. Hence, metal concentrations and physical–chemical parameters of Toledo River water were determined in order to complete an environmental evaluation catalog. Samples were collected monthly during one year period at seven different sites from the source down the river mouth, physical–chemical variables were analyzed, and major metallic ions were measured. Metal analysis was performed by using the synchrotron radiation total reflection X-ray fluorescence technique. A statistical analysis was applied to evaluate the reliability of experimental data. The analysis of obtained results have shown that a strong correlation between physical–chemical parameters existed among sites 1 and 7, suggesting that organic pollutants were mainly responsible for decreasing the Toledo River water quality.

Evaluation of water and sediment of the Graminha and Águas da Serra streams in the city of Limeira (Sp-Brazil) by Synchrotron Radiation Total Reflection X-ray Fluorescence

The city of Limeira is located in the state of São Paulo, Brazil and has the second largest economy and demographic growth of the state. It comprises an expressive economy with industries in several productive sectors. The source of the Graminha and Águas da Serra streams is located within the Limeira urban zone. The streams cross part of the rural zone and unite by draining into the Piracicaba River. It is possible that these basins suffer or have already suffered the impacts of environmental pollution caused by anthropogenic factors. Since the city has galvanization industries for the production of precious and semi-precious jewels as well as imitation jewelry, the concentration descriptions and interpretations of heavy metals in waters and sediments indicate anthropogenic influence and the dumping of these compounds into the Piracicaba River. The Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) was used for determining the metals. All measurements were performed using a white beam of synchrotron radiation for excitation and a Ge hyperpure detector. Detection limits for water samples were 0.04 μg L − 1 and in sediment samples 0.03 μg g − 1 for Cu and Zn elements. In the water samples, concentrations higher than permissible as established by the Brazilian legislation (CONAMA) for Al, Fe, Zn, Cr, Ni, Cu and Pb, were observed. For sediment samples, values higher than quality reference values defined by the Brazilian legislation (CETESB) were verified for Cr, Zn, Cu, Ni and Pb.

Multi-elemental analysis of produced water by synchrotron radiation total reflection X-ray fluorescence

The synchrotron radiation total reflection X-ray fluorescence (SRTXRF) technique was used for the analysis of heavy metals in produced water samples from oil field in Rio Grande do Norte, in order to determine potential sources of pollution. Since the inorganic components in produced water generally resembling sea water, pre-concentration procedures have been applied to increase the concentration of the analyte of interest and to minimize the salt matrix effects. This technique allows us to determine the contents of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Hg and Pb in 20 produced water samples. The great majority of the sampling points presented low elemental concentration value. However, in some sample, the Fe, Ni, Cu, Zn and Hg concentration were higher than the established limits by the Brazilian legislation.

Evaluation of the availability of heavy metals in lake sediments using SR-TXRF

The analytical technique Synchrotron Radiation Total Reflection X-ray Fluorescence (SR-TXRF) was used to evaluate the contamination and bioavailability of heavy metals in samples of sediment collected at different depths. The samples were collected in one of the lakes located next to ceramic industries in Santa Gertrudes, São Paulo state in the southwest region of Brazil during the rainy season. In order to determine the concentration of bioavailable metals (mobile fraction) and metals that are representative of the geological matrix (residual fraction) in sediment samples, procedures of acid extraction were implemented. All measurements were carried out in the Synchrotron Light Source Laboratory (LNLS), located in Campinas, São Paulo state. For sample excitation, a polychromatic beam of approximately 2 mm (width) and 0.3 mm (height) was used, and for the detection of the characteristic X-rays produced, a Si(Li) detector was employed. The net areas of the X-ray peaks were obtained from the program (Quantitative X-ray Analysis System; QXAS). The elements V, Cr, Co, Cu, Zn and Pb, which are considered to cause higher environmental damage, showed high availability. The concentrations of these elements are above the reference values which correspond to soil protection and underground water quality of São Paulo state. The concentrations obtained indicate that the area in study is contaminated.

Synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) for evaluation of food contamination

The objective of this study was to use synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF) for the determination of metals and other elements in food available to the population in commercial establishments, in order to evaluate the risks of contamination by these products. The analyzed species were vegetables, leafy vegetables, fruits, cereal and grain. The results indicated that some species were contaminated by Cr, Cu, Zn and Pb with concentrations much higher than the reference values.

Analysis of beers from Brazil with synchrotron radiation total reflection X-ray fluorescence

In this study the concentrations of P, S, Cl, K, Ca, Mn, Fe, Zn and Br in twenty-nine brands of national and international beers were determined by synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF). The results were compared with the limits established by the Brazilian legislation and the nutritional values established by National Agricultural Library (NAL, USA). The measurements were performed at the X-Ray Fluorescence Beamline at Brazilian National Synchrotron Light Laboratory, in Campinas, Sao Paulo, Brazil, using a polychromatic beam for excitation. A small volume of 5 ml of beers containing an internal standard used to correct geometry effects was analyzed without pretreatment. The measuring time was 100 seconds and the detection limits obtained varied from 1 mg . l-1 for Mn and Fe to 15 mg . l-1 for P.

Analysis of fish samples for environmental monitoring and food safety assessment by synchrotron radiation total reflection X-ray fluorescence

This study uses fishes as indicators of metal contamination in the Piracicaba Basin and also for evaluation of the risks to human health by the ingestion of fish contaminated by metals and other potentially toxic elements. Based on total reflection X-ray fluorescence analysis, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Ba were detected and evaluated in the muscle and viscus (liver, intestine and stomach) of fish collected in the Piracicaba River.

Monitoring of the environmental pollution by trace element analysis in tree-rings using synchrotron radiation total reflection X-ray fluorescence

This paper aims to study the environmental pollution in the tree development, in order to evaluate its use as bioindicator in urban and country sides. The sample collection was carried out in Piracicaba city, São Paulo State, which presents high level of environmental contamination in water, soil and air, due to industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. The species Caesalpinia peltophoroides (“Sibipiruna”) was selected because it is widely used in urban forestation. Synchrotron Radiation Total Reflection X-ray Fluorescence technique (SR-TXRF) was employed to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was performed in the Brazilian Synchrotron Light Source Laboratory, using a white beam for excitation and a Si(Li) detector for X-ray detection. In several samples, P, K, Ca, Ti, Fe, Sr, Ba and Pb were quantified. The K/Ca, K/P and Pb/Ca ratios were found to decrease towards the bark.

Multielement Analysis of Soft Drinks by X-ray Fluorescence Spectrometry

Several commercial soft drinks and respective plastic bottles were analyzed for their multielement contents employing the synchrotron radiation total reflection X-ray fluorescence spectrometry technique (SRTXRF). The SRTXRF method has been developed and validated, and about 20 elements were detected in the investigated samples, including some trace elements, which can be toxic for human beings, such as Ti, Cr, Sb, As, and Pb in soft drinks and Al, Sb, As, and Pb in poly(ethylene terephthalate) (PET) containers. Statistical analysis was performed using chemometric techniques (principal component analysis and cluster analysis), and similarities were verified in the multielement contents of the samples. The results demonstrated that the SRTXRF offers a good multielemental approach for the quality control of food products. Moreover, on the basis of enrichment factors, the possibility of the trace elements in the PET container may be leached to the beverages under normal commercial situations and other results were discussed.

Characterization of Hypoglycemiant Plants by Total Reflection X-ray Fluorescence Spectrometry

In this work, synchrotron radiation total reflection X-ray fluorescence spectrometry (SRTXRF) was used to determine trace elements in eight hypoglycemiant plants (Trigonella foenum graecum, Panax ginseng, Pfaffia paniculata, Myrcia speciosa, Zea mays, Harpagophytum procumbens, Syzygium jambolona, and Bauhinia forficate). The elements P, K, Ca, Ti, Mn, Fe, Cu, Zn, Rb, and Sr were detected in all medicinal plants investigated, whereas Si, S, Sc, V, Cr, Co, Ni, Se, Nb, Mo, Sn, Sb, Ba, Hg, and Pb were detected only in some of the samples. The concentration of elements in hypoglycemiant plants varied from 0.15 microg/g of Co to 3.0 x 10(4) microg/g of K and the mean of experimental limit of detection for these elements were 0.14 and 3.6 microg/g, respectively.

Metal-binding proteins scanning and determination by combining gel electrophoresis, synchrotron radiation X-ray fluorescence and atomic spectrometry

In the present work, protein bands from in vitro embriogenic callus ( Citrus sinensis L. Osbeck) were investigated using micro-synchrotron radiation X-ray fluorescence (μSR-XRF) after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) separation. Metal-binding protein quantification was done after microwave oven decomposition of gel by synchrotron radiation total reflection X-ray fluorescence (SR-TXRF), flame atomic absorption spectrometry (FAAS) and flame atomic emission spectrometry (FAES). According to the analysis of the protein bands, it is possible to observe that both 81 and ca. 14 kDa proteins present different Fe signal intensity at different positions. The analysis of 53 kDa protein, showed even more interesting results. Besides Fe, the μSR-XRF experiments indicate the presence of Ca, Cu, K and Zn. Chemical elements such as Cu, K, Fe and Zn were determined by SR-TXRF, Mg by FAAS and Na by FAES. Ca was determined by SR-TXRF and FAAS only for accuracy check. In the mineralised protein bands of 81 and around 14 kDa band, only Fe was determined (105 and 21.8 μg g −1). For those protein bands (86—ca. 14 kDa) were determined, Ca, K, Cu and Zn in a wide concentration range (42.4–283, 2.47–96.8, 0.91–15.9 and 3.39–29.7 μg g −1, respectively).