Synchrotron Radiation X-ray Fluorescence Spectroscopy Research Articles

Nondestructive characterization of diseased Chinese chive leaves using X-ray intensity ratios with microbeam synchrotron radiation X-ray fluorescence spectrometry.

The Chinese chive (Allium tuberosum) is a core crop grown in Kochi Prefecture, Japan. However, withering symptoms occur during greenhouse growing, which have a negative impact on crop management Chinese chive leaves with physiological disorders (PD) or necrotic streak disease (ND) present with withering as typical blight symptoms. Excess or deficiency of elements may cause such withering in Chinese chive leaves with PD. Therefore, visualizing the elemental distribution in plant bodies may help clarify the cause of this withering. In this study, using synchrotron radiation X-ray fluorescence (SR-XRF) imaging, we examined the elemental distribution conditions in healthy Chinese chive leaves without withering, those that withered due to PD, and those that withered due to ND. Segmentation analysis of inductively coupled plasma-optical emission spectroscopy (ICP-OES) was performed on the SR-XRF imaged Chinese chive leaves and the data from the two analytical methods were compared. SR-XRF imaging provided more detailed data on elemental distribution compared with segmentation analysis using ICP-OES. Based on the SR-XRF imaging results, the X-ray intensity ratios for Ca/K, Fe/Mn, and Zn/Cu were calculated. These findings support that the Ca/K, Fe/Mn, and Zn/Cu X-ray intensity ratios can be used in the early detection of withered leaves and to predict the factors causing withering.

Nondestructive discrimination of red silk single fibers using total reflection X-ray fluorescence spectrometry and synchrotron radiation X-ray fluorescence spectrometry.

In a strangulation case, when a necktie is used as a murder weapon, the dyed silk single fiber becomes an important evidence sample to solve the crime. Dyed silk single fibers contain elements, such as Cr and Co, which are obtained from dyeing using metal mordants. Currently, there are no nondestructive and sufficiently sensitive elementary analytical methods for the forensic analysis of single fibers. Therefore, in this study, eight commercially available red silk samples were collected and used for total reflection X-ray fluorescence (TXRF) and synchrotron radiation X-ray fluorescence (SR-XRF) spectrometry. Benchtop TXRF detected both S in the silk protein and Cl and Ca, which are elements absorbed from the environment by silkworms, but also Cr, which is a dyeing derivative for metal mordants. The presence of Cr and Zn, in addition to the Zn/Cr signal intensity ratios, was reported to be particularly useful identifiers. In SR-XRF, the presence of Cr, Co, Zn, and Br and the Zn/Cr signal intensity ratios were reported to be useful discriminating indicators. In this study, the nondestructive discrimination capabilities of TXRF and SR-XRF measurements for the samples were found to be 85.7% and 100%, respectively. Therefore, we propose a combination of TXRF and SR-XRF as a new nondestructive single fiber identification method for forensic science. Moreover, if partial destruction of a single fiber is allowed, the observation of the cross section and micro-Fourier-transform infrared spectroscopy measurements is useful for identifying red silk fibers.

Nanosafety evaluation through feces: A comparison between selenium nanoparticles and selenite in rats

Nanosafety evaluation is necessary not only for nanomaterials research and development but also as a cornerstone for legal regulation. In this study, we proposed a non-invasive protocol for nanosafety evaluation through feces using metagenomics and metabolomics together with metallomics. Male SD rats were orally exposed to equal amounts of Se (Se0NPs, 3.14 or Na2SeO3, 6.28 μg/kg bw) and were sacrificed after 24 h. 16S rRNA analysis and LC–MS were used to study the impact of different forms of Se on intestinal microbiota and metabolites in fecal samples. ICP-MS and synchrotron radiation X-ray fluorescence (SR-XRF) and X-ray absorption spectroscopy (XAS) were used to study the concentration and transformation of Se in gastrointestinal track and feces. It was found that Se0NPs brought less alternation to the composition of intestinal microbiota and metabolites related to inflammation, immunity and gut-brain axis related responses than Na2SeO3 did. Besides, the absorbed Se0NPs could be more efficiently converted to organic Se which explained the comparable bioavailability to Na2SeO3. In all, the proposed protocol combined with metagenomics, metabolomics and metallomics in this study can be used for nanosafety evaluation in a non-invasive manner and this may also be used for the screening of the nanosafety of other nanomaterials.

Traces of the Tunguska Event (1908) in Sediments of Zapovednoe Lake Based on SR–XRF Data

An anomalous layer enriched with chemical elements indicating the presence of terrigenous matter was discovered in the sediment core of Zapovednoe Lake located 60 km from the epicenter of the Tunguska event (1908) using synchrotron radiation X-ray fluorescence spectroscopy (SR–XRF). Radioisotope measurements indicate that the age of the layer is consistent with the date of the catastrophe. Apparently, the anomalous layer was formed as a result of an intense terrigenous matter inflow from the water catchment area due to massive forest falls and subsequent wildfires caused by the Tunguska event. Thus, it is established that targeted searches for microparticles of extraterrestrial origin can be carried out in the discovered and dated anomalous bottom sediment layer.

Quantitative evaluation of the intratumoral distribution of platinum in oxaliplatin-treated rectal cancer: In situ visualization of platinum via synchrotron radiation X-ray fluorescence spectrometry.

Oxaliplatin (l-OHP), a platinum-based drug, is a key chemotherapeutic agent for colorectal cancer (CRC), but drug resistance and toxic effects have been major limitations of its use. Synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) is a rapid, nondestructive technique for monitoring the distribution of metals and trace elements in cells or tissue samples. We applied SR-XRF to visualize the distribution of platinum and other elements in 30 rectal cancer specimens resected from patients who received l-OHP-based preoperative chemotherapy and quantified platinum concentration in the tumor epithelium and stroma, respectively, using calibration curves. The platinum concentration in rectal cancer tissue ranged 2.85-11.44 ppm, and the detection limit of platinum was 1.848 ppm. In the tumor epithelium, the platinum concentration was significantly higher in areas of degeneration caused by chemotherapy than in nondegenerated area (p < 0.001). Conversely, in the tumor stroma, the platinum concentration was significantly higher in patients with limited therapeutic responses than in those with strong therapeutic responses (p < 0.001). Furthermore, multivariate analysis illustrated that higher platinum concentration in the tumor stroma was an independent predictive factor of limited histologic response (odds ratio; 19.99, 95% confidence interval; 2.04-196.37, p = 0.013). This is the first study to visualize and quantify the distribution of platinum in human cancer tissues using SR-XRF. These results suggest that SR-XRF analysis may contribute to predicting the therapeutic effect of l-OHP-based chemotherapy by quantifying the distribution of platinum.

Synchrotron Radiation Research and Analysis of the Particulate Matter in Deep Ice Cores: An Overview of the Technical Challenges

Airborne dust extracted from deep ice core perforations can provide chemical and mineralogical insight into the history of the climate and atmospheric conditions, with unrivalled temporal resolution, time span and richness of information. The availability of material for research and the natural complexity of the particulate, however, pose significant challenges to analytical methods. We present the developments undertaken to optimize the experimental techniques, materials and protocols for synchrotron radiation-based analysis, in particular for the acquisition of combined Synchrotron Radiation X-Ray Fluorescence and X-ray Absorption Spectroscopy data.

Analysis of occurrence, bioaccumulation and molecular targets of arsenic and other selected volcanic elements in Argentinean Patagonia and Antarctic ecosystems

In Latin America, the high proportion of arsenic (As) in many groundwaters and phreatic aquifers is related to the volcanism of the Andean Range. Nevertheless, there is still very little published research on As and other elements occurrence, and/or transference to biota in Southern regions such as Argentinean Patagonia and the South Shetland Islands in Antarctica, where there are active volcanoes and geothermal processes. Therefore, this study was aimed to describe water quality from the main rivers of Argentinean Northern Patagonia through physicochemical analysis. The Patagonian and Antarctic biota (including samples of animal, plants, algae and bacteria) was characterized through the analysis of their As and other elemental concentrations (P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Se, Br, Rb and Sr), by synchrotron radiation x-ray fluorescence spectroscopy (SRXRF). Finally, the analysis of metal and As-proteins associations in As-accumulating organisms was performed by SRXRF after sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). A wide range of metal concentration including As (up to 950 μg/L As) was found in water samples from Patagonian rivers. A hierarchical cluster analysis revealed that the elemental concentration of analysed biological samples was related to volcanic environments and their place in the trophic chain. Moreover, the results suggest that Se, Co, Cu, Br, and Cl are strong predictors of As in biota. On the other hand, As was not detected in proteins from the studied samples, suggesting biotransformation into soluble As-organic compounds. This is the first study to describe environmental pollution as a consequence of active volcanism, and its influence on water quality and elemental composition of biota in Argentinean Northern Patagonia and Antarctica.

Forensic Comparison of Automotive Aluminum Wheel Fragments Using Synchrotron Radiation X-ray Fluorescence with 18- and 116-keV Excitation X-rays.

The performance of synchrotron radiation X-ray fluorescence (SR-XRF) spectrometry for nondestructive discrimination of small fragments of automotive aluminum wheels was studied. Fragments (< 500 × 500 μm2 ) of 45 kinds of wheels were first analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and then by SR-XRF. Despite the Mg/Al intensity ratio being a useful identification index, SEM-EDS was not efficient enough because of the absence of other meaningful indicators of comparison. Conversely, pairwise comparison was conducted and a 92.9% identification was achieved via SR-XRF using 18-keV X-rays. Trace heavy elements in the high-energy region were detected by SR-XRF using 116-keV X-rays, and an 82.9% identification was obtained. Combined use of 18- and 116-keV X-rays allowed 98.2% identification. Hence, SR-XRF is a powerful tool for nondestructive discrimination of automotive aluminum wheels with high precision using trace elements in a wide energy region.

Long-term Monitoring of Metal Elements in Total Suspended Particle Aerosols Simultaneously Collected at Three Islands in Okinawa, Japan

In the present study, total suspended particle (TSP) aerosols were simultaneously collected using identical high-volume air samplers at three islands in Okinawa; Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS, Okinawa Island), from 2008 to 2012 Kume Island (KM, ca. 160 km south-west of CHAAMS), and Minami-Daitou Island (MD, ca. 320 km south-east of CHAAMS) from 2008 to 2010. The sample collected were analyzed using energy-dispersive X-ray fluorescence spectrometry (ED-XRF) and synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) to investigation long-range transport of metal elements to Okinawa from the Asian continent. From analytical data on samples collected at CHAAMS for five years, it was found that most elements (Ca, Fe, Ti, Mn, V, Cu, Ni, Pb, As, and Zn) in TSP aerosols showed higher concentrations in the period from October to May, when the continental air mass passed over Okinawa, regardless of Asian dust events. The annual average concentrations of Ni, Cu, Zn, As, Se, and Pb in TSP aerosol samples collected at three islands gradually decreased as the TSP aerosols traveled from west to east in any year. Based on the enrichment factors (EFs) and concentration ratios, it is considered that most of anthropogenic elements such as As, Pb, and Zn in TSP aerosols are derived from coal combustion in the Asian continent. Moreover, it is confirmed from the direction of the air mass reaching the sampling sites that Cu, Zn, As, and Pb in TSP aerosols were transported to the three islands in Okinawa by air mass not only from northwest and north, but also from the west. These TSP aerosols transported from the Asian continent may influences not only the atmospheric environment but also the concentrations of trace metals in coastal seawater in Okinawa, which have to be kept extremely low to preserve the diverse and unique ecosystem in coral reefs.

Development and prospect of biological effects and safety of nanomaterials

Nanomaterials have lots of unique physical and chemical properties, such as quantum size effect, surface effect and macroscopic quantum tunnel effect. The biological effects of nanomaterials might be different from those of bulk materials larger than microns even if their chemical compositions are same. Therefore, the biological effects and safety evaluation results obtained from the bulk materials might not be suitable for the nanomaterials. Since 2003, governments worldwide have initiated the researches on biological effects and safety issues of nanomaterials with increasing financial support. China is one of the earliest countries in the world to carry out researches on biological effects and safety issues of nanomaterials. And some research fields have entered the forefront of the world. The CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety established jointly by National Center for Nanoscience and Technology (NCNST) and Institute of High Energy Physics of Chinese Academy of Sciences (IHEP of CAS) was the first professional laboratory focusing on the biological effects and safety of nanomaterials in China. Scientists in this laboratory have done many in-depth studies of the relationship between the physical-chemical properties and biological responses of nanomaterials. They found several factors which affected the biological effects of carbon nanotubes significantly, such as nanoparticle-Crona, metal impurities, surface, size, shape and so on. They have also established multiple models for hazard recognition and risk assessment. Nanomaterials/nanoparticles (NMs/NPs) are exposed to human beings mostly through four routes, i.e., oral intake, skin contact, inhalation, and intravenous injection. Upon entering the body, NMs/NPs are quickly distributed into specific organs and then metabolized primarily by the liver. The final excretion of NMs/NPs usually occurs in the liver and kidney in the form of urine and feces. In general, the most important issues regarding the absorption, distribution, metabolism and excretion (ADME) processes of NMs/NPs include: (1) Where do and how much NMs/NPs get in (via absorption)? (2) Where do and how much NMs/NPs go (via distribution)? (3) How much, when do, and what form of NMs/NPs remain intact (via metabolism)? (4) Where do, how much, and what form of NMs/NPs stay in the system (via excretion)? At various stages of the ADME processes, the challenges for in vivo analysis of NMs/NPs may become largely different. Important analytical methods to resolve the analytical challenges for each absorption, distribution, metabolism and excretion (ADME) process are summarized. The state-of-the art techniques with high sensitivity and high resolution suitable for safety evaluation have been developed to ensure the sustainable development of nanotechnology, such as inductively coupled plasma mass spectrometry (ICPMS), inductively coupled plasma optical emission spectrometry (ICP-OES), nuclear analysis such as neutron activation analysis (NAA), laser ablation inductively coupled plasma mass spectrometry (LAICPMS), secondary ion mass spectrometry (SIMS), synchrotron radiation X-ray fluorescence spectroscopy (SRXRF), X-ray absorption spectroscopy (XAS), X-ray fluorescence spectroscopy (XRF), scanning transmission X-ray microscopy (STXM), transmission X-ray microscopy (TXM) and so on. In this review, we summarize these research progresses in recent years.

Nanoelemental selenium alleviated the mercury load and promoted the formation of high-molecular-weight mercury- and selenium-containing proteins in serum samples from methylmercury-poisoned rats

Selenite (Se4+) has been found to counteract the neurotoxicity of methylmercury (MeHg) in MeHg-poisoned rats. However, Se4+ has narrow range between its toxic and beneficial effects. Nanoelemental selenium (SeNPs) was found to be less toxic than other forms of Se such as Se4+. In this study, the effects of SeNPs on the load of mercury (Hg) in rats were investigated. Hyphenated technique based on size-exclusion chromatography coupled with UV and inductively coupled plasma mass spectrometry (SEC-ICP-MS) detection and synchrotron radiation X-ray fluorescence spectroscopy (SR-XRF) were used to analyze the Hg-Se-containing proteins in the serum from MeHg-poisoned rats. The Hg-Se-containing fractions monitored by UV and ICP-MS were further characterized by MALDI-TOF-MS. Elevated serum Hg and Se levels were found in MeHg-poisoned rats after SeNPs treatment. Three main Hg-containing bands with molecular weights (MWs) of 25, 62 and 140 kDa were detected in the control samples. Treatment with SeNPs increased the Hg content in proteins at 62 and 170 kDa and decreased the Hg content at 25 kDa. The fraction with 25 kDa was assigned to metallothioneins (MTs), and fractions with 40 and 75 kDa were assigned to albumin. This study showed that the low-toxicity SeNPs could reduce the Hg load in the tissues and promote the formation of high molecular weight Hg- and Se-containing proteins in MeHg-poisoned rats.

Comparative measurement of metal contents in raw and cooked rice samples prepared in different rice cookers using SR-XRF and health risk assessment

Rice is full of nutrients that are essential to humans, however, exposure to the high metal contents in rice could also pose potential health risks to consumers. This work aimed to investigate this safety concern using the synchrotron radiation X-ray fluorescence spectrometry (SR-XRF), which is considered one of the most advanced and accurate elemental analysis techniques, to quantify metal contents, namely Fe, Zn, Cu, Ca, and Mn, in raw and cooked rice samples in order to assess the potential health risks associated with rice consumption. The results indicated that cooked rice samples had lower Fe and Ca but higher Zn, Cu, and Mn contents than raw rice samples (p < 0.05). The highest changes in metal contents were the decrease in the Ca content, which was reduced up to 8.5 times in rice samples cooked with running water and was lower than the detection limit (< 2.0 mg kg−1) in rice samples cooked with de-ionized water. When comparing the average estimated weekly intake with the available provisional tolerable weekly intake (PTWI) issued by the World Health Organization (WHO), the results showed that Fe, Zn, and Cu had lower average estimated weekly intake values than the PTWI levels. In terms of chronic, non-carcinogenic health risk assessment, the individual hazard quotient (HQ) of each metal of interest was less than the limit (1.0). However, the hazard index (HI), which combined all HQ values, was 1.15, indicating possible chronic health risks from rice consumption. The results obtained from this work suggest that further investigation is needed to fully understand and to promote awareness of the health risks caused by rice consumption.

Assessment of Toxic Metals and Hazardous Substances in Tattoo Inks Using Sy-XRF, AAS, and Raman Spectroscopy.

Synchrotron radiation X-ray fluorescence spectroscopy, in conjunction with atomic absorption and Raman spectroscopy, was used to analyze a set of top brand tattoo inks to investigate the presence of toxic elements and hazardous substances. The Cr, Cu, and Pb contents were found to be above the maximum allowed levels established by the Council of Europe through the resolution ResAP(2008)1 on requirements and criteria for the safety of tattoos and permanent makeup. Raman analysis has revealed the presence of a set of prohibited substances mentioned in ResAP(2008)1, among which are the pigments Blue 15, Green 7, and Violet 23. Other pigments that were identified in white, black, red, and yellow inks are the Pigment White 6, Carbon Black, Pigment Red 8, and a diazo yellow, respectively. The present results show the importance of regulating tattoo ink composition.

Nickel and platinum in high-temperature H2O + HCl fluids: Implications for hydrothermal mobilization

The dissolution of NiS and NiAs (nickeline) in 0.1 and 1 molal HCl at 400 °C, 80 MPa, and of PtAs2 (sperrylite) and Pt metal in 1 and 6.86 molal HCl at 500 °C, 80 MPa was studied in-situ using synchrotron radiation X-ray fluorescence and absorption spectroscopy. The Pt concentration in the fluid averaged 8 · 10−5 molal (12.8 ppm) during dissolution of Pt metal in 6.86 molal HCl, and was below the minimum detection limit (mdl; 2.6 · 10−5 molal) in all other experiments. Dissolution of NiS was congruent or nearly congruent. Equilibrium was attained rapidly in about 250 min at an initial HCl concentration of 1 molal HCl, and in about 500 min at 0.1 molal HCl. Addition of HCl resulted in a large increase in the Ni solubility from 7.2 · 10−3 molal Ni (423 ppm) at 0.1 molal HCl to 8.72 · 10−2 molal Ni (4959 ppm) at 1 molal HCl. Dissolution of NiAs in 0.1 and 1 molal HCl was incongruent. A steady state was not reached even at a run duration of more than 16 h, and the maximum recorded Ni concentrations in the fluid were much lower than the Ni solubility in the corresponding experiments with NiS at the same HCl molality. Measured K-edge XANES spectra in comparison with literature data indicated that arsenic in the fluid was present as As(V) and that nickel complexed with Cl and H2O as tetrahedral [NiCl2(H2O)2]0 and [NiCl3(H2O)]− and octahedral [NiCl2(H2O)4]0 species. In addition, Raman spectra of H2O + NiCl2 and H2O + NiCl2 + HCl solutions and of H2O + HCl fluids reacted with NiS crystals were acquired at temperatures (T) up to 600 °C and pressures (P) up to 1.15 GPa. All spectra at T ≥ 300 °C and P < 600 MPa showed a previously not reported Raman peak at ∼280 cm−1 together with a weaker peak at ∼230 cm−1. These peaks can be assigned to Ni–Cl vibrations. The band at 280 cm−1 was not detected at the other P-T conditions. Based on calculated vibrational frequencies available in the literature, it may stem from the species [NiCl4]2– or [NiCl2(H2O)4]0, although particularly the first assignment is in conflict with the information from published XAS data.The results of this study demonstrate that nickel is readily mobilized by acidic chloridic hydrothermal fluids, but platinum remains practically immobile in such fluids at any HCl concentration that is conceivable to occur in nature. Therefore, the enrichment of Pt relative to Ni in footwall-type deposits in the Sudbury District and the growth of large sperrylite crystals are likely related to magmatic processes. Furthermore, the experiments point to the importance of redox reactions for the mobilization and precipitation of arsenides and suggest that arsenate species are more stable in hydrothermal fluids than previously thought.

Elemental Investigation of the Leaf and Seed of Coriander Plant by Synchrotron Radiation X-ray Fluorescence Spectroscopy

This study describes the potential of synchrotron radiation X-ray fluorescence spectroscopy technique for the investigation of elements present in the parts of the medicinally important coriander plant: leaf and seed. For this, X-ray fluorescence spectra of the leaf and seed of coriander plants have been recorded by exciting synchrotron radiation of energy 13 keV. The analyses of the procured spectrum show the presence of elements: potassium, calcium, titanium, chromium, manganese, iron, nickel, copper, zinc, and arsenic. A calibration free approach, PyMca has been used for the quantitative estimation of the detected elements in the leaf and seed of the coriander plant.

Nanoscopic tumor tissue distribution of platinum after intraperitoneal administration in a xenograft model of ovarian cancer

There is increasing interest in the treatment of advanced stage ovarian cancer (OC) using intraperitoneal (IP) delivery of platinum (Pt)-based chemotherapy. The antitumor efficacy of IP chemotherapy is determined by efficient tumor tissue penetration. Although it is assumed that Pt penetration is limited to a few millimeters after IP delivery, little is known on the distribution of Pt in different tumor compartments at the ultrastructural level following IP administration.Here, using synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), Pt distribution and penetration in OC peritoneal xenografts were determined at nanometer scale after IP chemoperfusion of cisplatin at 37–38°C or 40–41°C (hyperthermic). Using principal component analysis (PCA) the presence of phosphorus, manganese, calcium, zinc, iron, bromine, and sulfur was correlated with the distribution of Pt, while k-means analysis was used to quantify the amount of Pt in weight% in tumor stroma and in tumor cells.The results showed a heterogeneous distribution of Pt throughout the tumor, with an accumulation in the extracellular matrix. LA-ICP-MS mappings indicated significantly higher concentrations of Pt (P=0.0062) after hyperthermic chemoperfusion of cisplatin, while SR-XRF demonstrated a deeper tissue Pt penetration after hyperthermic treatment. Using PCA, it was showed that Pt co-localizes with bromine and sulfur. No differences were observed in Pt distribution regarding tumor cells and stroma, when comparing normo- vs. hyperthermic treatment.In conclusion, SR-XRF and LA-ICP-MS are suitable and highly sensitive techniques to analyze the penetration depth and distribution of Pt-based drugs after IP administration. To the best of our knowledge, this is the first experiment in which the distribution of Pt is analyzed at the cellular level after IP administration of cisplatin.

Copper Uptake, Intracellular Localization, and Speciation in Marine Microalgae Measured by Synchrotron Radiation X-ray Fluorescence and Absorption Microspectroscopy.

Metal toxicity to aquatic organisms depends on the speciation of the metal and its binding to the critical receptor site(s) (biotic ligand) of the organism. The intracellular nature of the biotic ligand for Cu in microalgal cells was investigated using the high elemental sensitivity of microprobe synchrotron radiation X-ray fluorescence (SR-XRF) and X-ray absorption near-edge spectroscopy (XANES). The marine microalgae, Ceratoneis closterium, Phaeodactylum tricornutum, and Tetraselmis sp. were selected based on their varying sensitivities to Cu (72-h 50% population growth inhibitions of 8-47 μg Cu/L). Intracellular Cu in control cells was similar for all three species (2.5-3.2 × 10(-15) g Cu/cell) and increased 4-fold in C. closterium and Tetraselmis sp. when exposed to copper, but was unchanged in P. tricornutum (72-h exposure to 19, 40, and 40 μg Cu/L, respectively). Whole cell microprobe SR-XRF identified endogenous Cu in the central compartment (cytoplasm) of control (unexposed) cells. After Cu exposure, Cu was colocated with organelles/granules dense in P, S, Ca, and Si and this was clearly evident in thin sections of Tetraselmis sp. XANES indicated coexistence of Cu(I) and Cu(II) in control and Cu-exposed cells, with the Cu ligand (e.g., phytochelatin) in P. tricornutum different from that in C. closterium and Tetraselmis sp. This study supports the hypothesis that Cu(II) is reduced to Cu(I) and that polyphosphate bodies and phytochelatins play a significant role in the internalization and detoxification of Cu in marine microalgae.

Metal elements in tissue with dental peri-implantitis: a pilot study.

Dental peri-implantitis is characterized by a multifactorial etiology. The role of metal elements as an etiological factor for peri-implantitis is still unclear. The aim of this study was to investigate the incidence of metal elements in bone and mucosal tissues around dental Grade 4 CP titanium implants with signs of peri-implantitis in human patients. In this prospective pilot study, all patients were enrolled consecutively in two study centers. Bone and soft tissue samples of patients with peri-implantitis with indication for explantation were analyzed for the incidence of different elements (Ca, P, Ti, Fe) by means of synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) and polarized light microscopy (PLM). The existence of macrophages and lymphocytes in the histologic specimens was analyzed. Biopsies of 12 patients (seven bone samples, five mucosal samples) were included and analyzed. In nine of the 12 samples (75%), the SRXRF examination revealed the existence of titanium (Ti) and an associated occurrence with Iron (Fe). Metal particles were detected in peri-implant soft tissue using PLM. In samples with increased titanium concentration, lymphocytes were detected, whereas M1 macrophages were predominantly seen in samples with metal particles. Titanium and Iron elements were found in soft and hard tissue biopsies retrieved from peri-implantitis sites. Further histologic and immunohistochemical studies need to clarify which specific immune reaction metal elements/particles induce in dental peri-implant tissue.

Quantification estimate methods for synchrotron radiation X-ray fluorescence spectroscopy

Synchrotron radiation X-ray fluorescence spectroscopy is a method which allows low elemental concentrations to be measured within a sample. To maintain biological or medical relevance increased importance is being placed on quantifying these in situ localized elemental concentrations. For third generation synchrotron light sources, which have the potential for high sample throughput, a rapid method of obtaining a quantification estimate is needed. Non-destructive transmission and surface analysis techniques for first transition metals, or elements of higher atomic number, using reference standards are examined for different sample property regimes to elucidate methods of quantitative synchrotron radiation X-ray fluorescence spectroscopy.

Elemental composition of species of the genus Pentaphylloides (Rosaceae) in the Russian Far East

The elemental composition of species of the genus Pentaphylloides Hill. from the Russian Far East is studied by means of synchrotron radiation X-ray fluorescence spectrometry (SR XFS). It is shown that the species Pentaphylloides davurica, P. davurica × P. sp., and Dasiphora gorovoi accumulate larger amounts of macroelements, while the species P. mandshurica and P. fruticosa store elevated amounts of trace elements. Accumulation is associated with both the content of elements in the soil and species traits of the plants. Based on the findings, samples prepared from the stems of species P. davurica are recommended as a standard for chemotaxonomic investigations of the genus Pentaphylloides Hill. by SR XFS.