The determination of zinc,copper and iron oxidation state in invasive ductal carcinoma of breast tissue and normal surrounding tissue using XANES

X‐ray absorption near‐edge structure (XANES) spectroscopy was used to examine the oxidation state of Zn, Fe and Cu in 22 normal and 23 tumour regions spread over 30 formalin‐fixed, paraffin‐embedded tissue samples of human primary invasive breast cancer. A micro‐mapping analysis of the metal distribution in the tissue was performed prior to the XANES analysis to identify and localise the metals in the tumour and normal tissue regions. The aim of this study was to identify the oxidation state of Zn, Fe and Cu in normal and tumour tissues of the breast, in order to correlate the oxidation state of these elements with the carcinogenesis process. The position of the Zn K‐edge in normal and tumour tissues suggests that Zn exists in a bounded form. The shape of the Cu K‐edge XANES spectra and the first derivative spectra of normal and tumour tissues shows that a significant portion of the total copper is present as Cu (I). Nevertheless, the position of the edges in the normal and tumour tissue spectra does not exclude the presence of Cu (II). The shape and position of both normal and tumour regions of the tissue suggest that they contain mixtures of Fe (II) and Fe (III) ions with a significant fraction being Fe (III). However, normal tissue regions were found to have a higher fraction of Fe (II) compared to the tumour tissues. In order to estimate the best target for therapy, more information is required about the relative abundance of Zn, Fe and Cu binding proteins, their oxidation state and their localisation at the subcellular level. Copyright © 2010 John Wiley & Sons, Ltd.     

The use of X‐ray interaction data to differentiate malignant from normal breast tissue at surgical margins and biopsy analysis

X‐ray interaction data, including measuring bio‐metal levels and scattering characteristics, are being shown to be a possible discriminating variable in the classification of human tissues. However, a major concern when using X‐ray interaction data in breast cancer material is that the samples are rarely 100% tumour because of the invasive nature of the disease. The work reported here includes a methodology to help overcome this limitation as the experimental protocol includes mapping the data to histological analysis of the measured samples. This work has shown how important it is to relate the measured X‐ray parameters to the histology of the samples, particularly the clinical information that describes the percentage of tumour within each sample. Levels of K, Ca, Zn, Fe, Cu, Br and Rb were evaluated using X‐ray fluorescence and compared between tumour breast tissue and normal surrounding breast tissue. The coherent scattering properties of each sample were also examined using an angular dispersive X‐ray diffraction technique. Multivariate modelling using soft independent modelling of class analogy was used to classify samples kept out of the modelling procedure. A significant increase (p < 0.01) in the levels of Rb, Zn and K was found in the tumour samples. The levels of these elements show a correlation with the percentage of tumour reported to be present in a given sample. The results of classifying unknown tissue samples are presented using two‐class and three‐class models that help to reveal the importance of sample histology in studies involving breast cancers. Copyright © 2013 John Wiley & Sons, Ltd.     

Measurement of K,Fe, Cu and Zn levels in secondary colorectal liver cancer and surrounding normal liver tissue,and their potential as a tissue classifier

An x‐ray fluorescence (XRF) system utilising a synchrotron radiation source was used to quantify the levels of Fe, Cu, Zn and K in colorectal liver metastases and surrounding normal liver tissue as a possible mechanism for detecting cancer in a tissue biopsy. Sixty samples were measured and a lower level of all four elements was found in the cancer samples compared with that of the normal liver. The difference in levels of Zn, Fe, Cu and K between cancer and normal tissue was significant with p values of < 0.01 for Zn, Fe and K, and 0.033 for Cu. The precision was estimated by repeated measurements yielding a precision of 96, 91, 95 and 86% for Zn, Cu, Fe and K, respectively. The homogeneity of the distribution of elemental concentrations was assessed by measuring eight normal liver and eight cancer samples from the same patient. The variation of Zn, Cu, Fe and K levels between normal liver samples was 10.4, 15.4, 15.85 and 29.1%, respectively, and in the colorectal metastases was 10.18, 15.92, 8.44 and 22.35%, respectively. Receiver operator characteristic (ROC) analysis was performed for all elements and showed that Zn could be a reliable indicator of tissue classification with an ROC area under the curve of 0.998 and a resulting sensitivity and specificity of 100 and 96.67%, respectively. Fe had an ROC area under the curve of 0.856 and sensitivity and specificity of 83.3 and 76.67%, respectively. Cu and K did not perform as well with areas under the curve of 0.75 and 0.706, respectively. Copyright © 2008 John Wiley & Sons, Ltd.     

Characterization of essential and toxic elements in cephalopod tissues by EDXRF and AAS

Concentrations of K, Ca, Cr, Fe, Ni, Cu, Zn, Se, Rb, Sr, Cd, Hg and Pb were measured in the muscle, digestive glands and gonads of Octopus vulgaris, Lolligo vulgaris and Sepia officinalis captured in the west and south coast of Portugal. Essential elements (K, Ca, Fe, Cu, Zn, Se, Rb and Sr) were obtained by energy dispersive x‐ray fluorescence spectrometry, while toxic elements (Cr, Ni, Cd, Hg and Pb) were obtained by atomic absorption spectrometry. The latter technique was used owing to its higher sensitivity, since these elements were not detected by the first technique. The tissues of the three species present a similar pattern for essential elements. Potassium and Ca are present at the highest concentration in all the studied samples. The highest levels for toxic elements were found in the digestive glands, exceeding the maximum allowed values in the case of Se and Cd. However, in the muscle tissue these values were never reached. Comparing both coasts, we can say that the west coast presents higher levels of Pb while the south coast presents enhanced levels of Hg. Copyright © 2007 John Wiley & Sons, Ltd.     

Synchrotron study of metal localization in Typha latifolia L. root sections

Understanding mechanisms that control plant root metal assimilation in soil is critical to the sustainable management of metal‐contaminated land. With the assistance of the synchrotron X‐ray fluorescence technique, this study investigated possible mechanisms that control the localization of Fe, Cu, Mn, Pb and Zn in the root tissues of Typha latifolia L. collected from a contaminated wetland. Metal localizations especially in the case of Fe and Pb in the dermal tissue and the vascular bundles were different. Cluster analysis was performed to divide the dermal tissue into iron‐plaque‐enriched dermal tissue and regular dermal tissue based on the spatial distribution of Pb and Fe. Factor analysis showed that Cu and Zn were closely correlated to each other in the dermal tissues. The association of Cu, Zn and Mn with Fe was strong in both regular dermal tissue and iron‐plaque‐enriched dermal tissue, while significant (p < 0.05) correlation of Fe with Pb was only observed in tissues enriched with iron plaque. In the vascular bundles, Zn, Mn and Cu showed strong association, suggesting that the localization of these three elements was controlled by a similar mechanism. Iron plaque in the peripheral dermal tissues acted as a barrier for Pb and a buffer for Zn, Cu and Mn. The Casparian strip regulated the transportation of metals from dermal tissues to the vascular bundles. The results suggested that the mechanisms controlling metal localization in root tissues varied with both tissue types and metals.     

Characterization of Fe,Cu and Zn in organs of PDAPP transgenic mice by XRF spectrometry

A large body of evidence indicates that abnormalities in the levels of iron, copper and zinc and their metabolism are associated with neurodegenerative diseases. However, it is difficult to decide whether any observed changes of trace elements reflect the primary disease process or are secondary to a primary process or mechanism. In the present study, Fe, Cu and Zn in organs of transgenic mice which express the familial Alzheimer's disease (AD) gene and normal mice of the same species and ages were determined by X‐ray fluorescence (XRF) spectrometry. The results show that Fe concentrations in a variety of organs and tissues were significantly increased whereas Zn concentrations decreased in the transgenic mice as compared with the ‘normals’. The levels of Cu in transgenic mice were also altered. Data obtained in the present study suggest that expression of the familial AD gene in mice results in altered homeostasis of Fe, Cu and Zn in organs of the animals, which may in turn accelerate the process of neurodegeneration. Copyright © 2006 John Wiley & Sons, Ltd.     

Evaluation of metal release from battery and electronic components in soil using SR‐TXRF and EDXRF

Potentially toxic elements may be leached contaminating the soil, surface, and ground water due to the improper disposal of batteries and electronic devices. The objective of this study was to evaluate metal release from batteries and electronic components deposited in specific receptacles filled with soil in which acid rain was simulated. The leachate solution and the soil were analyzed by synchrotron radiation total reflection x‐ray fluorescence and benchtop energy dispersive x‐ray fluorescence, respectively. Results indicate that batteries released K, Mn, Fe, Cu, Zn, and Pb and electronic component released Ti, Mn, Fe, Cu, Zn, and Pb. For batteries' leachate test samples, higher amounts of Fe, Cu, Mn, Zn, and Pb have been released compared with electronic component ones under same the experimental conditions. The Fe, Cu, and Pb concentrations in battery leachate test samples were above their National Environment Council maximum permitted values (MPV) and in the electronic waste leachate ones, only the Pb concentrations was above MPV. For soil sample containing batteries K, Mn and Zn presented higher concentrations, mainly at the 10‐cm topsoil, ranging from 0.16 to 0.50, 0.27 to 8.67, and 0.03 to 1.26, in % (% w/w), respectively. The Zn–C battery soil samples present similar behavior to the alkaline ones. The impact due to the Pb release was higher in the soil test samples with electronic components, in which their concentrations ranged from 51 to 394 mg/kg, above its MPV up to 28‐cm soil layer. The X‐ray fluorescence techniques employed were suitable for water and soil environmental evaluation.     

Investigation of a fossilized calotte from Lagoa Santa,Brazil, by EDXRF

The origin of the component parts of a fossilized calotte (skull cap) from Lagoa Santa in Brazil was investigated by using energy‐dispersive x‐ray fluorescence analysis. The specimen was irradiated with a miniaturized and low‐power x‐ray generator (2.25 W, tungsten anode). The calotte and rock samples from the two known sites have a similar chemical composition, especially rich in S, K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Br, Rb and Sr. These elements are associated with the geological constitution of the limestone complex where the archaeological samples were found. The small differences in the relative amount of each element, especially the Ca/Sr ratio, in different parts of the calotte reinforce the hypothesis that the calotte had been mounted with pieces from different origins. Copyright © 2005 John Wiley & Sons, Ltd.     

Intraneuronal investigations of organic components and trace elements with the use of synchrotron radiation

Three techniques based on synchrotron radiation microbeam analysis were applied to biochemical investigations of human central nervous system (CNS) tissue. Thin tissue slices representing Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and control cases were studied. Synchrotron radiation microbeam x‐ray fluorescence (micro‐SRXRF) was applied to the analysis of the elemental distribution inside single nerve cells. Investigation of copper oxidation state was performed with the use of micro x‐ray absorption near‐edge structure spectroscopy (micro‐XANES). Moreover, the organic components of the tissues were analyzed by means of synchrotron radiation Fourier transform infrared microspectroscopy (SR‐FTIRM). Topographic differences in elemental composition were observed for the nerve cell body. Higher levels of Fe, Zn and Ca were found for the neurons of PD cases in comparison with the control group. The IR spectra measured in neurons of PD, ALS and control cases showed differences in absorption bands associated with characteristic groups of selected biological molecules. Additionally, results of SR‐FTIRM measurements indicated inhomogeneous accumulation of the main organic components in PD nerve cells, in contrast to the control cases. Copyright © 2005 John Wiley & Sons, Ltd.     

Time‐resolved x‐ray fluorescence for monitoring the intake of mineral nutrients in living plants

We have applied a time‐resolved means of measurement for studying living plants. The intake of mineral nutrients in a living plant such as stevia has been observed by this measuring instrument. A solution containing K, Ca, Mn, Fe, Cu, and Zn compounds was used as the mineral nutrient solution. The concentrations of the standard solutions were specifically chosen to obtain optimal intensities of the x‐ray peaks. The time dependence of the x‐ray fluorescence (XRF) intensity showed specific intake processes depending on the type of element. In addition, the experimental results suggest differences in the translocation of each element in the stevia stem. We conclude that time‐resolved XRF is a powerful technique for studying living plants. Copyright © 2007 John Wiley & Sons, Ltd.     

Trace element mapping of a single cell using a hard x‐ray nanobeam focused by a Kirkpatrick‐Baez mirror system

To visualize the distributions of trace elements in biological samples such as tissues and cells at high spatial resolution, we developed a scanning x‐ray fluorescence microscope (SXFM) at SPring‐8, using a Kirkpatrick‐Baez mirror optics that enables achromatic and highly efficient focusing. To evaluate performance regarding its application to biological samples, the SXFM was used at x‐ray energy of 15 keV to observe NIH/3T3 cells in which adenosine triphosphate (ATP) synthase β (specifically localized at the mitochondria) were labeled with gold colloidal particles. Various elemental distributions were visualized at the single‐cell level, including those for P, S, Cl, Ca, Fe, Cu, Zn and Au, and we obtained high‐resolution elemental distribution maps by magnifying the labeled single mitochondrion. Maximum spatial resolution achieved in the experiments was sub‐100 nm. Copyright © 2008 John Wiley & Sons, Ltd.     

The use of combined trace element XRF and EDXRD data as a histopathology tool using a multivariate analysis approach in characterizing breast tissue

The concentrations of K, Fe, Cu and Zn were measured in 77 breast tissue samples (38 classified as normal and 39 classified as diseased) using x‐ray fluorescence (XRF) techniques. The coherent scattering profiles were also measured using energy‐dispersive x‐ray diffraction (EDXRD), from which the proportions of adipose and fibrous tissue in the samples were estimated. The data from 30 normal samples and 30 diseased samples were used as a training set to construct two calibration models, one using a partial least‐squares (PLS) regression and one using a principal component analysis (PCA) for a soft independent modelling of class analogy (SIMCA) technique. The data from the remaining samples, eight normal and nine diseased, were presented to each model and predictions were made of the tissue characteristics. Three data groups were tested, XRF, EDXRD and a combination of both. The XRF data alone proved to be most unreliable indicator of disease state with both types of analysis. The EDXRD data were an improvement, but with both methods of modelling the ability to predict the tissue type most accurately was by using a combination of the data. Copyright © 2004 John Wiley & Sons, Ltd.     

Broad‐beam PIXE and µ‐PIXE analysis of normal and in vitro demineralized dental enamel

Dental enamel has been widely studied by particle‐induced x‐ray emission (PIXE), but less attention was paid to its demineralization, which leads to caries formation. Using broad‐beam PIXE and µ‐PIXE, we investigated normal enamel and the in vitro formation of pre‐carious lesion in lactic acid solution, aiming also to evaluate intercusp differences within the same tooth. Broad‐beam PIXE was performed using 3.0 MeV protons, and µ‐PIXE maps of Ca, Fe and Zn were collected with 3.1 MeV protons at ～4 µm resolution. In normal enamel a differentiated Ca‐rich surface layer was observed, where Fe and Zn reached their highest levels. In deeper layers, Fe and Zn evidenced quasiperiodic patterns of maxima, possibly due to coupled diffusion‐reaction catalytic processes involved in the enamel growth. Both Fe and Zn appeared to be located in a few distinct types of pools. Near the surface, demineralization induced an increase of Fe, Cu, Zn, Sr and Pb with respect to Ca, attributed to partial hydroxyapatite dissolution and/or to chelate extraction and concentration of trace metals. Ca maps revealed limited changes in the surface layer and a massive loss in the inner enamel; here, Fe was almost depleted and Zn partially removed. The maps of Ca, Fe and Zn demonstrated major intercusp variations in both normal and altered enamel. Thus, broad‐beam PIXE and µ‐PIXE, which do not require (semi)thin sectioning of the tooth as the conventional methods, provide compositional and structural insight of normal dental enamel, of its intercusp variability and of the alterations produced by in vitro demineralization, largely not accessible to the current techniques, and highly relevant for understanding the incipient caries formation. Copyright © 2008 John Wiley & Sons, Ltd.     

Elemental composition of marine sponges from the Berlengas natural park,western Portuguese coast

Analytical studies of sponges have recently become a matter of interest, since these organisms have been reported to accumulate high levels of some elements, including heavy metals, which may have an anthropogenic origin, allowing their application as environmental pollution indicators. In the present work, 35 sponges collected in August 1998 at the Berlengas Natural Park were classified and analysed by secondary target energy‐dispersive x‐ray fluorescence spectrometry (EDXRF). Some major, minor and trace elements could be determined: Al, Si, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Sr, Zr, I and Pb. To assess some local influences on the sponge composition, two sediment samples were also taken from the area and analysed. Besides these elements, sponges are constituted by fairly high percentages of elements that do not emit characteristic x‐ray lines. Therefore, absorption corrections for quantitative calculations were carried out taking into account the ratio between the inelastic and elastic scattered incident radiation from a silver secondary target to calculate the mean atomic number of the light matrix. Calibration was performed using chemical compounds and standard reference materials. Precision, accuracy and detection limits for the range of elements determined by the method are particularly suitable for the chemical analysis of these organisms. Results for the sediment chemical composition indicated the existence of high Ca and low Si levels and confirmed the absence of any trace metal contamination in the region. The sponge composition showed low Si contents, even in siliceous specimens. Certain high elemental contents determined in some species indicated a clear selective bioaccumulation of particular trace elements, such as Ni, Zn and As, which is not dependent on local influences. Copyright © 2003 John Wiley & Sons, Ltd.     

Levels and sources of heavy metal contamination in road dust in selected major highways of Accra,Ghana

Environmental studies have revealed significant contributions of vehicular exhaust emissions to high pollution levels in urban dwellings. The levels and sources of heavy metal contaminations of some major roads in Accra have been investigated in this work. Street dust samples collected from four major roads in Accra (Mallam Junction‐Weija road, John Teye‐Pokuase road, Tema Motorway and Tetteh Quarshie Interchange in Accra) were analysed for their elemental concentrations using energy‐dispersive X‐ray fluorescence. Twenty elements were identified: K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Rb, Sr, Y, Zr and Pb. Significant concentration levels were obtained for K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn, Br, Rb, Sr, Y, Zr and Pb in all the samples and were used for the source identification. Enrichment factors and principal component analysis were used to verify the anthropogenic contribution to road dust. Results obtained for the enrichment factors showed moderate enrichment for V, Cr and Cu, while Zn, Br, Zr and Pb were significantly enriched. Principal component analysis identified four sources and their contributions to the elemental contents in the road dust. Natural crust, brake wear, tyre wear and vehicle exhaust emission were the four sources identified. The contribution of vehicular non‐exhaust emissions to heavy metal contamination in the road dust was found to be greater than that of exhaust emissions. Copyright © 2012 John Wiley & Sons, Ltd.     

X‐ray fluorescence analysis of trace metals in environmental water using preconcentration with an iminodiacetate extraction disk

A simple and convenient x‐ray fluorescence analysis procedure for trace amounts of Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg and Pb in water was developed using preconcentration with an iminodiacetate extraction disk (IED). The IED was coated on both faces with commercially available laminate film to prevent x‐ray damage to the IED by strong x‐irradiation (4 kW; 50 kV, 80 mA) of the wavelength‐dispersive x‐ray fluorescence spectrometer. Lamination of the IED prolongs its life from 7 to about 200 min at 4 kW irradiation while negligibly decreasing the x‐ray fluorescence. Lowering the power of primary x‐rays to less than 1.5 kW compensated for the Hg evaporation. Linear calibration curves were obtained over the range 500 µg–5 mg for Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg and Pb. Detection limits corresponding to three times the standard deviation of the blank intensity were 0.1–0.4 µg for Mn, Co and Ni, 0.5–0.8 µg for Fe, Cu, Zn and Pb and 7 µg for Cd. A spike test for 10 µg of eight analytes, excluding Mn, showed good recoveries (90–100%) for city water and rainwater. Analytical results for municipal tap water and rainwater agreed well with values obtained using atomic absorption spectrometry. Copyright © 2006 John Wiley & Sons, Ltd.     

Elemental mapping of frozen‐hydrated cells with cryo‐scanning X‐ray fluorescence microscopy

Visualizing the elemental distributions of cells and tissues is of growing importance in biology and medical science because such data deepen our understanding of the behavior of metal‐binding proteins and ions. Elemental mapping by X‐ray fluorescence analysis with a hard X‐ray nanobeam is very well suited for this purpose owing to its high sensitivity and high resolution. Using this technique, samples must be prepared without artifacts that are caused by treatments such as chemical fixation and staining procedures. In many studies of elemental mapping, sample preparation is not explicitly considered. To overcome this deficiency, we developed a cryo‐scanning X‐ray fluorescence microscope and installed it in the second experimental hutch of BL29XUL of SPring‐8. We used it to observe frozen‐hydrated cells that had been fixed by a quick‐freezing technique to preserve elemental data of the living state at an X‐ray energy of 11.5 keV. The distributions of K, Ca, Fe, Cu and Zn were successfully visualized. The distributions of these elements (especially those of K, Ca and Fe) differed from those in cells fixed with paraformaldehyde. Copyright © 2010 John Wiley & Sons, Ltd.     

SRXRF microprobe as a technique for studying elements distribution in Elsholtzia splendens

Elsholtzia splendens is a copper tolerant plant growing in copper mine areas in south of China and accumulates considerable heavy metals in plant tissue. In this study, synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe was used to study the Cu and other elements distribution in E. splendens. The element (P, S, Cl, K, Ca, Mn, Fe, Cu, Zn) in the leaf epidermis and cross-sections of the stem and leaf could be checked by SRXRF which was considered a sensitive technique for trace element analysis. The highest Cu levels were measured in the vascular tissues of stem and petiole, while Cu levels in mesophyll were higher than in leaf epidermis. The levels of most elements were not higher in trichomes than in other tissues. It seems that the celluar compartmentation of heavy metals in epidermis and epidermal trichomes was not the general feature of all plants. There was a significant correlation between Cu and P, S, Ca in distribution, which suggested P, S, and Ca played an important role in Cu accumulation of E. splendens. Based on the significant correlation between Cu and elements Mn, Fe, and Zn in distribution, it seemed that Cu, Mn, Fe, and Zn could be transported by the same transporters with a broad substrate range.     

Trace element categorization of pollution sources in the equator town of Nanyuki,Kenya

An air pollution campaign was carried out in the town of Nanyuki at four different sites during July and August 1999. Nanyuki is situated on the equator on the northwestern slope of Mount Kenya at about 1930 m above sea level. The intention of the project was to characterize aerosol elemental compositions in two size fractions, associated with specific natural and anthropogenic activities. A dichotomous impactor was used for sampling and an energy‐dispersive x‐ray fluorescence spectrometer was used for the analysis. Fourteen elements (Si, S, K, Ca, Ti, Mn, Fe, Cu, Zn, Ga, Br, Rb, Sr and Pb) were analysed in all the samples. The concentration of Pb was highest at a site in the vicinity of open‐air vehicle garages. The four sites recorded high concentrations of fine S, Cl and K. Fine Zn and Br were also measured at all the sites. In the coarse size range, the concentrations of soil‐derived elements (Si, K, Ca and Fe) were dominant. The high concentration of coarse Cl was considered to be due to the contribution of sea salt and that of S to be a contribution of gas to particle conversion of SO₂. The two elements S and Cl signified the influence of long‐distance transported aerosols. The comparatively high concentrations of fine Pb and Br signified the high rate of vehicle repairs, which is a major activity close to one of the sites. Generally, soil dust‐derived particles and those from biomass burning dominated the town aerosols. Copyright © 2004 John Wiley & Sons, Ltd.     

Speciation of selected metals in aerosol samples by TXRF after sequential leaching

Total reflection x‐ray fluorescence (TXRF) spectrometry was applied after sequential leaching for the speciation of selected elements in particulate matter, in order to complete the knowledge of the mobility of the selected elements and to determine which components are harmful to works of art. Samples were collected on filters in two churches, one situated in a rural area and the other in an urban area. A five‐stage sequential leaching scheme for the speciation of K, Ca, Fe, Zn and Pb was applied, the fractions obtained being as follows: exchangeable elements; elements bound to carbonates; elements bound to Fe and Mn oxides; elements bound to organic matter; and the digested insoluble residue. It was found that, in the case of the church in the urban area, much of the K, Fe and Zn appeared as mobile elements, whereas for the church situated in the rural area, the amounts of Ca and Fe were most mobile. Copyright © 2006 John Wiley & Sons, Ltd.