Ion Microanalysis Research Articles

Evolution of melts of the Changbaishan Tianchi volcano (China–North Korea) as a model of ore–magmatic system formation: Data from melt inclusions studies

The composition and evolution of the melts of trachytes from the volcano were studied based on examining the inclusions of mineral-forming media by means of X-ray and ion microanalysis. A correlation was shown between the degree of enrichment of these melts in rare elements and the processes of magmatic differentiation. It was found that trachytes of the volcano were generated in highly differentiated alkaline melts enriched in Hf, Nb, Zr, Ta, U, Th, Rb, Y, and REEs under 1020–1060°C. The evolution of melts was determined by the processes of crystal fractionation. The main volatile components in the melts are water, fluorine, and chlorine with the concentrations of 0.1–0.5, 0.2–0.5, and 0.2–0.3 wt %, respectively. The melt crystallization was accompanied by degassing caused by the decrease in the outer pressure. The low concentrations of water and fluorine represent the melt composition by these components exclusively at the time of the melt movement towards the Earth’s surface just before the eruption.

Simultaneous determination of heavy metal ions in water using near-infrared spectroscopy with preconcentration by nano-hydroxyapatite

A method for simultaneous determination of metal ions in river water was developed by using preconcentration and near-infrared diffuse reflectance spectroscopy (NIRDRS). An inorganic biomaterial, nano-hydroxyapatite (HAP) was used as a high-efficient adsorbent for gathering the ions from water samples. After adsorbing the analytes onto the adsorbent, NIRDRS was measured and partial least squares (PLS) models were established for fast and simultaneous quantitative prediction. With the samples prepared by river water, determination of Pb2+, Zn2+, Cu2+, Cd2+ and Cr3+ was investigated. The calibration models of Cu2+, Cr3+ and total content were proven to be efficient enough for precise prediction. The determination coefficients (R2) of the independent validation were found as high as 0.9924, 0.9869 and 0.9273 for Cu2+, Cr3+ and total content, respectively. Therefore, the feasibility of NIRDRS for microanalysis of heavy metal ions in waste water was demonstrated.

Quantitative micro-analysis of metal ions in subcellular compartments of cultured dopaminergic cells by combination of three ion beam techniques

Quantification of the trace element content of subcellular compartments is a challenging task because of the lack of analytical quantitative techniques with adequate spatial resolution and sensitivity. Ion beam micro-analysis, using MeV protons or alpha particles, offers a unique combination of analytical methods that can be used with micrometric resolution for the determination of chemical element distributions. This work illustrates how the association of three ion beam analytical methods, PIXE (particle induced X-ray emission), BS (backscattering spectrometry), and STIM (scanning transmission ion spectrometry), allows quantitative determination of the trace element content of single cells. PIXE is used for trace element detection while BS enables beam-current normalization, and STIM local mass determination. These methods were applied to freeze-dried cells, following a specific cryogenic protocol for sample preparation which preserves biological structures and chemical distributions in the cells. We investigated how iron accumulates into dopaminergic cells cultured in vitro. We found that the iron content increases in dopaminergic cells exposed to an excess iron, with marked accumulation within distal ends, suggesting interaction between iron and dopamine within neurotransmitter vesicles. Increased iron content of dopaminergic neurons is suspected to promote neurodegeneration in Parkinson's disease.

Characterization of Si p-i-n diode for scanning transmission ion microanalysis of biological samples

The performance of a silicon p-i-n diode (Hamamatsu S1223-01) for the detection of charged particles was investigated and compared with the response of a standard passivated implanted planar silicon (PIPS) detector. The photodiode was characterized by ion beam induced charge collection with a micrometer spatial resolution using proton and alpha particle beams in the 1–3MeV energy range. Results indicate that homogeneity, energy resolution, and reproducibility of detection of charged particles enable the use of the low cost silicon p-i-n device as a replacement of conventional PIPS detector during scanning transmission ion microanalysis experiments. The Si p-i-n diode detection setup was successfully applied to scanning transmission ion microscopy determination of subcellular compartments on human cancer cultured cells.

Qualitative microanalysis of ions and ultrastructural changes in dentin exposed to laser irradiation and to metal salts solution

This study evaluated the ultrastructural changes in dentin after treatment with the Nd:YAG laser and/or metal salt solutions and verified the presence of Sn++, Sr++, and F- in dentin structure. Sixty dentin disks were randomly divided into groups (n = 10): (I) control (no treatment), (II) Nd:YAG (1.5 W, 100 mJ, 15 Hz, 125 J/cm2), (III) 10% SnF2 aqueous solution for 30 minutes, (IV) Nd:YAG+10% SnF2 aqueous solution for 30 minutes, (V) 10% SrCl2 toothpaste for 30 minutes, (VI) Nd:YAG+10% SrCl2 toothpaste for 30 minutes. Then, all samples were prepared for scanning electron microscopy (SEM) and the samples from Groups I to IV for the energy dispersive X-ray microanalysis (EDX). SEM evaluation revealed occluded dentinal tubules and a dentin surface altered by the laser irradiation. The EDX microanalysis revealed Sn++ at a depth of 250 microm in Group IV and not deeper than 100 microm in Group III. In Group V, Sr++ was not deeper than 50 microm, but it could be detected at a depth of 500 microm in Group VI. F- was found only in Group IV. Ultrastructural changes caused by laser irradiation can increase dentin uptake of Sn++, Sr++, and F-.

Characterization of Intra‐Cellular Ionic Concentrations of Monocytes in Contact with Bioactive Glasses and Hydroxyapatite Particles. A TEM Cryo‐X‐ray Analysis of Diffusible Ions

A cells viability can be altered by the presence of bioactive materials particles and their features. This paper compares the influence of hydroxyapatite particles and bioactive glass particles on intracellular ionic concentrations of the monocytes exposed to them. However, microanalysis of intracellular ions like sodium, potassium, and chlorine is a major problem. In order to limit diffusion phenomenon and to preserve the chemical identity of specimens, we used cryomethods (cryo‐preparation, and cryo‐x‐ray microanalysis) to study cells in contact with bioactive materials particles. We measured intracellular ionic concentrations by scanning transmission electron microscopy (STEM) associated with energy dispersive x‐ray spectroscopy (EDXS). Monocytes were exposed to bioactive glass particles and to hydroxyapatite particles during 2 days. The K/Na ratio was used as a sensitive criteria of viability of cells. Bioactive glass particles and, in a less manner, hydroxyapatite particles have an effect on intracellular ionic concentrations. These two types of bioactive particles alter cells. However, bioactive glass particles appear to alter cells more than hydroxyapatite particles.

Restrictin-P/stromal activin A, kills its target cells via an apoptotic mechanism.

We have recently found that the inhibitor of plasmacytoma cell growth, restrictin-P, is a stroma derived activin A and that it is an antagonist of interleukin-6 and interleukin-11. The present study was aimed at determining the mode by which this cytokine kills its target cells. On addition of the cytokine there was little or no net increase in cell number, depending on the specific target cells. All plasmacytoma cell lines tested exhibited a similar time dependent inhibition of DNA synthesis and a G0/G1 shift in the cell cycle. Electron microscope examination revealed classical apoptotic features i.e. chromatin condensation and membrane blebbing. DNA fragmentation, measured qualitatively and quantitatively, occurred in all cytokine treated plasmacytoma cell lines. Bovine activin A had an identical capacity to reduce cell viability, to induce G0/G1 shift and to cause DNA fragmentation. X-ray microanalysis of intracellular ions revealed an increase in calcium ions, following exposure of plasmacytoma cells to restrictin-P, accompanied by a decrease in phosphor ions. The cytotoxicity of the inhibitor was augmented in an additive manner by cycloheximide (CHX) indicating that the process did not require de novo protein synthesis. This study thus shows that restrictin-P/stromal activin A kills its target cells by inducing apoptosis. This effect was mediated by subnanogram concentrations and therefore may represent one physiological function of this pleiotropic cytokine.

C-NEXAFS Microanalysis and Scanning X-ray Microscopy of Microheterogeneities in a High-Volatile A Bituminous Coal

Carbon near-edge X-ray absorp ion microanalysis was applied to the study of the chemistry of macerals in ultrathin sections of a high-volatile A bituminous coal. High-resolution images were obtained by exploiting variations in the intensity of carbon-edge fine structure for contrast. The macerals vitrinite, cutinite, and sporinite were distinguishable based on the relative intensities of two prominent absorption bands. The lower energy band, at 285.5 eV, was assigned to the transition of the core (1s) electron to the valence π * MO; the absorption intensity correlated with the concentration of aromatic carbon. The higher energy band, near 288 eV, was assigned to a transition of an electron from the core (1s) to a mixed Rydberg/valence (C-H * ) state; the intensity of this band correlated with the concentration of aliphatic carbon. Inertinite's inner-shell spectrum was distinct from those of the other macerals by a relatively intense 1s-π * absorption band, absorption due to transitions to higher energy π * MO's associated with polynuclear aromatics, moderate absorption near 288 eV, and a shoulder at 289.5 eV which was assigned to oxygen containing functionality. At the highest energies, E ∼295 eV, absorptions due to transitions to * states were present in the carbon spectra of each maceral type

Microanalytical Determination of ZnO Solidus and Liquidus Boundaries in the ZnO‐Bi2O3 System

ZnO solidus and liquidus boundaries in the ZnO‐Bi2O3 system were investigated via analytical electron microscopy (AEM), electron probe microanalysis (EPMA), and secondary ion mass spectrometry (SIMS). The Bi2O3 solubility is highest—0.24 ± 0.04 mol%—at the eutectic temperature of 740°C and decreases rapidly with increasing temperature. Detection limits and quantification procedures of X‐ray microanalysis (AEM, EPMA) and ion microanalysis (SIMS) are discussed with respect to the determination of phase diagrams involving low solubility phases.

IMAP : a complete Ion Micro-Analysis Package for the nuclear microprobe

Microprobe techniques using scanned, focused MeV ions are routinely used in Livermore for materials characterization. Comprehensive data analysis with these techniques is accomplished with the computer software package IMAP, for Ion Micro-Analysis Package. IMAP consists of a set of command language procedures for data processing and quantitative spectral analysis. Deconvolution of the data is achieved by spawning sub-processes within IMAP which execute analysis codes for each specific microprobe technique. IMAP is structured to rapidly analyze individual spectra or multi-dimensional data blocks which classify individual events by the two scanning dimensions, the energy of the detected radiation and, when necessary, one sample rotation dimension. Several examples are presented to demonstrate the utility of the package.

Electron and Ion Microscopy and Microanalysis Principles and Applications

Electron and Ion Microscopy and Microanalysis Principles and Applications

Advanced Boron Soaking Procedure for Steam Generators.

An experimental study on boric acid penetration into the crevices between tube and tube-support-plate, and intergranular-attack (hereinafter called IGA) cracks in crevices has been performed to obtain the optimum boron soaking procedure in operating steam generators with IGA. is a corrosion mechanism involving the dissolution of the metal grain boundary. It consists of several cracks which propagate along metal grain boundaries from the outer surface to the inside of the tube. The term IGA crack refers to these cracks. Two experimental crevice models were set up. One was of the packed-crevice type where the crevice gap is completely packed by sludge, and the other was of the open-crevice type where the crevice gap is not packed, but reduced by sludge. The boron in cracks was investigated using ion microanalysis in order to confirm the existence of anticorrosive film in propagation. The optimum reactor power for effective boric acid penetration into the tube surface and into the cracks within the crevice was found to be a power level of about 5% and 30%, which are applicable to both the packed-and open-crevice types.

Analysis of HgI2 And PbI2 Crystals and Detectors by Particle-Induced X-Ray Emission (PIXE) and Ion Backscattering Spectroscopy (IBS)

ABSTRACTThe Ion Micro-Analysis Group (IMAG) in Livermore conducts quantitative trace elemental analysis with PIXE and depth profiling with IBS using an MeV ion microbeam. The system has the capability to produce two-dimensional trace element and IBS images. PIXE analyses have been conducted on HgI2 and PbI2 crystals and detector materials in order to identify and quantify near surface trace contaminants. IBS measurements have been conducted to investigate elemental depth distributions in various materials. The results of measurements on several different samples are reported and a discussion of factors affecting quantitative in vacuo microanalysis of these materials is presented.

X-ray microanalysis of intracellular ions in epithelial tissues

Electron probe x-ray microanalysis provides a powerful tool in studying transepithelial ion transport mechanisms as it allows the quantitative detection of diffusible ions on a cellular and subcellular scale. The high spatial resolution afforded by this method is of particular advantage in epithelial tissues that are composed of different cell types and cases in which the transcellular transport pathway might involve different intracellular compartments. In the following, the methods applied in several studies are described, with emphasis on some recent modifications.The tissues are frozen by rapid immersion in liquified ethane kept at -180°C. Support systems for different epithelial preparations have been developed to facilitate freezing and maintain the functional state of the epithelium immediately up to the moment of freezing. A fluid-clamp technique is used to mount the tissue for sectioning (Figure 1). Sections are cut dry at -140°C and a nominal thickness of 200 nm using 40° glass knifes. The sections are picked up from the back of the knife by a fire-polished wire probe (1 μm tip diameter) and placed on a parlodion film which is suspended over a 2 mm opening in a special beryllium carrier disc.

Investigation on corrosion resistance of metal superficially modified with alkoxy titanates

A study has been made in order to determine corrosion protection performance of alkoxy titanate modified iron in a 3% NaCl solution. The effectiveness of alkoxy titanates as corrosion retarders for chloride environments is confirmed by both stepped potential sweep technique and electrochemical impedance spectroscopy (EIS). Ion microanalysis (IMA) depth profile are used to elucidate the corrosion inhibitive action of different alkoxy titanate.

Intracellular localization of drugs in cultured tumor cells by ion microscopy and image processing

Several drugs, containing a halogen atom, F or Br, that are being used in antiviral or anticancer therapy, were studied for their localization in cultured cells by ion microanalysis. The association allows to reduce the exposure time to define the intracellular localization of the studied element. The topography of the cells is given by the image of the polyatomic ion 26CN-. The image of the distribution of 81Br- or 19F-, coded in another color scale, can be superimposed, giving a polychromic image of the cell, thus showing the intracellular localization of the compound. MCF-7 tumor cells were cultured in the presence of pyrimidine derivatives. 5-Bromo-2'-deoxyuridine (BUdR) and 5-trifluorothymidine (F3TdR) were localized in the nucleus, 5-fluoro-2'-deoxyuridine (FUdR) in the nucleus and only in some nucleoli. The method is simple and rapid, as compared with techniques using radiolabeled compounds, or with immunocytochemical techniques. It is possible to observe two different compounds in the same cell. It could be applied to other compounds containing a halogen atom.

Implanted standards for ion microanalysis of oxygen in beryllium

Implantation of 150 keV O + into polycrystalline beryllium provided internal standards for the trace analysis of oxygen in beryllium using secondary ion mass spectroscopy (SIMS). Four different oxygen fluences (1.3, 3.8, 13, and 38 × 10 14 O cm 2 ) were used to give calculated peak oxygen concentrations of 120–3700 atomic parts per million (appm) at a depth of about 310 nm. Since the measured SIMS oxygen profiles were considerably broader than that calculated by the TRIM-86 Monte-Carlo simulation program, the known integral amounts of oxygen were used to quantify the SIMS intensities. This implantation/SIMS approach permitted reliable analysis for isolated oxygen atoms in polycrystalline beryllium matrices. For the profiling conditions employed, a detection limit of about 10 appm was established. By varying the current density of the analyzing Cs + beam, this limit was found to be controlled by oxygen-bearing, residual gases at the surface region under analysis.

Cytochemical study of abnormal intranuclear structures rich in beryllium

During prolonged intoxication with beryllium sulphate, intranuclear beryllium-rich structures (IBRS) develop mainly in the cells of the convoluted tubules of the kidney. These structures are constituted by the accumulation of dense granules approximately 20 nm in diameter. The present work shows: 1) by electron probe microanalysis that IBRS are rich in phosphorus and calcium, and 2) by high resolution ion microanalysis that the granules are rich in beryllium and proteins. Staining with thallium alcoholate and regressive staining with ethylenediaminetetraacetate (EDTA) seem to demonstrate the presence of ribonucleoproteins in the granules. But the richness in calcium and phosphorus makes it difficult to interprete cytochemical reactions based on thallium and lead because complexes can be formed between calcium and thallium or lead, and between phosphorus and lead. Extraction with EDTA and digestion with RNase carried out on floating slices fixed with glutaraldehyde and embedded in glycol methacrylate show that: 1) the positive response of IBRS to cytochemical techniques used seems due solely to calcium; 2) the RNase forms a stable complex with a constituent of the granules that could be the highly phosphorylated acidic protein that binds preferentially to beryllium described by Parker and Stevens.

Investigation of the sampling volume in secondary ion microanalysis II. Evidence of oxide formation during O implantation in pure elements

AbstractSpecimen modification in secondary ion microanalysis caused by oxygen primary ion bombardment has been studied for pure elements. The steady‐state primary ion implantation volumes in Al, Si. Fe, Nb, Mo, Ta, and W could be analysed by scanning Auger microanalysis depth profiling, transmission electron microscopy, and electron diffraction imaging. The specimen region modified by the primary ions is found to consist of a metal–oxide phase mixture of various degrees of microcrystallinity, involving amorphous components, too. Whereas chemical state is represented by equilibrium compounds the lattice structure can be of metastable or quasi‐equilibrium configuration.

Investigation of the sampling volume in secondary ion microanalysis III. Peculiarities of multi‐element metal specimens under oxygen bombardment

AbstractThe modification caused by oxygen primary ion bombardment in homogeneous multi‐element metal specimens has been studied. Investigations of the appropriate sample region of Fe40Ni40P14B6 and Fe81Si3.5C2B13.5 metallic glasses by transmission electron microscopy, electron diffraction and scanning Auger microanalysis revealed an inhomogeneous steady‐state sampling volume. Chemical decomposition of the initial matrix, precipitation of oxide components and formation of crystalline phases have been proven.