Microprobe analysis of ferric iron in garnet: The Flank Method and case application

Abstract The oxidation state of iron in upper mantle minerals is widely used to constrain the Earth mantle's oxidation state. Previous studies showed high levels of ferric iron in high-pressure majoritic garnets and pyroxenes despite reducing conditions. To disentangle the effects of pressure and increasing oxygen fugacity on the Fe3+/ΣFe ratios of garnet and clinopyroxene, we performed high-pressure experiments at a pressure of 10 GPa in a 1000-ton Walker-type multi-anvil apparatus at the University of Münster. We synthesized majoritic garnets and clinopyroxenes with a total iron content close to natural mantle values at different oxygen fugacities, ranging from IW+4.7 to metal saturation at IW+0.9. We analyzed the iron oxidation state in garnets with the electron microprobe “flank method.” Furthermore, we investigated the oxidation state of iron in garnets and clinopyroxenes with transmission electron microscopy (TEM) electron energy loss spectroscopy (EELS). Although the flank method measurements are systematically lower than the EELS measurements, Fe3+/ΣFe obtained with both methods agree well within 2σ errors. The “flank method” has the advantage of being much faster and more easily to set up, whereas TEM-EELS has a much higher spatial resolution and can be applied to various non-cubic minerals such as orthopyroxenes and clinopyroxenes. We used our experimental results to compare two geobarometers that contain a term for ferric iron in garnet (Beyer and Frost 2017; Tao et al. 2018) with two geobarometers that do not account for ferric iron (Collerson et al. 2010; Wijbrans et al. 2016). We found that for garnets with low total Fe and Fe3+ (like many natural garnets), the pressures can be calculated without including the ferric iron content.

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Advances in Microprobe Analysis Applied to Muscle, Nerve and Gland

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054601 ◽

1982 ◽

Vol 40 ◽

pp. 404-407

Author(s):

T. E. Hutchinson ◽

D. E. Johnson ◽

A. C. Lee ◽

E. Y. Wang

Keyword(s):

Biological Tissue ◽

Microprobe Analysis ◽

Physiological State ◽

External Environment ◽

Physiological Relevance ◽

Muscle Nerve ◽

Technique Development

Microprobe analysis of biological tissue is now in the end phase of transition from instrumental and technique development to applications pertinent to questions of physiological relevance. The promise,implicit in early investigative efforts, is being fulfilled to an extent much greater than many had predicted. It would thus seem appropriate to briefly report studies exemplifying this, ∿. In general, the distributions of ions in tissue in a preselected physiological state produced by variations in the external environment is of importance in elucidating the mechanisms of exchange and regulation of these ions.

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Microbulldozing and Microchiseling

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062580 ◽

1969 ◽

Vol 27 ◽

pp. 134-135

Author(s):

J.N. Ramsey ◽

D.P. Cameron ◽

F.W. Schneider

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Material Handling ◽

Microprobe Analysis ◽

Foreign Matter ◽

Specific Location ◽

Potential Problems ◽

Knoop Indenter ◽

Scanning Electron ◽

Microhardness Tester

As computer components become smaller the analytical methods used to examine them and the material handling techniques must become more sensitive, and more sophisticated. We have used microbulldozing and microchiseling in conjunction with scanning electron microscopy, replica electron microscopy, and microprobe analysis for studying actual and potential problems with developmental and pilot line devices. Foreign matter, corrosion, etc, in specific locations are mechanically loosened from their substrates and removed by “extraction replication,” and examined in the appropriate instrument. The mechanical loosening is done in a controlled manner by using a microhardness tester—we use the attachment designed for our Reichert metallograph. The working tool is a pyramid shaped diamond (a Knoop indenter) which can be pushed into the specimen with a controlled pressure and in a specific location.

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Scanning Electron Microscopy and Electron Microprobe Analysis of Malignant Cell Cultures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100561 ◽

1968 ◽

Vol 26 ◽

pp. 164-165

Author(s):

R. I. Johnsson-Hegyeli ◽

A. F. Hegyeli ◽

D. K. Landstrom ◽

W. C. Lane

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Cell Cultures ◽

Electron Microprobe ◽

Microprobe Analysis ◽

Electron Microprobe Analysis ◽

Three Dimensional ◽

Malignant Cell ◽

Interference Microscopy ◽

Scanning Electron

Last year we reported on the use of reflected light interference microscopy (RLIM) for the direct color photography of the surfaces of living normal and malignant cell cultures without the use of replicas, fixatives, or stains. The surface topography of living cells was found to follow underlying cellular structures such as nuceloli, nuclear membranes, and cytoplasmic organelles, making possible the study of their three-dimensional relationships in time. The technique makes possible the direct examination of cells grown on opaque as well as transparent surfaces. The successful in situ electron microprobe analysis of the elemental composition and distribution within single tissue culture cells was also reported.This paper deals with the parallel and combined use of scanning electron microscopy (SEM) and the two previous techniques in a study of living and fixed cancer cells. All three studies can be carried out consecutively on the same experimental specimens without disturbing the cells or their structural relationships to each other and the surface on which they are grown. KB carcinoma cells were grown on glass coverslips in closed Leighto tubes as previously described. The cultures were photographed alive by means of RLIM, then fixed with a fixative modified from Sabatini, et al (1963).

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Ultrastructure and analytical microprobe analysis of simian lung mite pigments

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143249 ◽

1986 ◽

Vol 44 ◽

pp. 324-325

Author(s):

R. W. Cole ◽

J. C. Kim

Keyword(s):

Biomedical Research ◽

Tissue Damage ◽

Microprobe Analysis ◽

Old World Monkeys ◽

Old World ◽

Experimental Animals ◽

The Past ◽

Lung Mite ◽

Mite Infestations ◽

Cardiopulmonary System

In recent years, non-human primates have become indispensable as experimental animals in many fields of biomedical research. Pharmaceutical and related industries alone use about 2000,000 primates a year. Respiratory mite infestations in lungs of old world monkeys are of particular concern because the resulting tissue damage can directly effect experimental results, especially in those studies involving the cardiopulmonary system. There has been increasing documentation of primate parasitology in the past twenty years.

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Fluorescence effects in quantitative microprobe analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134533 ◽

1990 ◽

Vol 48 (2) ◽

pp. 188-189

Author(s):

S.J.B. Reed

Keyword(s):

Microprobe Analysis ◽

Depth Distribution ◽

Exciting Radiation ◽

Primary Radiation ◽

List Type ◽

Type Number ◽

Computing Power ◽

X Ray ◽

Fluorescent Radiation

Characteristic fluorescenceThe theory of characteristic fluorescence corrections was first developed by Castaing. The same approach, with an improved expression for the relative primary x-ray intensities of the exciting and excited elements, was used by Reed, who also introduced some simplifications, which may be summarized as follows (with reference to K-K fluorescence, i.e. K radiation of element ‘B’ exciting K radiation of ‘A’):1.The exciting radiation is assumed to be monochromatic, consisting of the Kα line only (neglecting the Kβ line).2.Various parameters are lumped together in a single tabulated function J(A), which is assumed to be independent of B.3.For calculating the absorption of the emerging fluorescent radiation, the depth distribution of the primary radiation B is represented by a simple exponential.These approximations may no longer be justifiable given the much greater computing power now available. For example, the contribution of the Kβ line can easily be calculated separately.

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Least-square refinement of structure parameters from CBED integrated intensities: application to determination of temperature factors in Y BA2CU3O7

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131917 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1456-1457

Author(s):

Kjersti Gjønnes ◽

Jon Gjønnes

Keyword(s):

Least Square ◽

Measured Intensity ◽

Structure Information ◽

Accurate Temperature ◽

Least Square Fit ◽

Case Application ◽

Integrated Intensities ◽

Temperature Factors ◽

Narrow Bands

Electron diffraction intensities can be obtained at large scattering angles (sinθ/λ ≥ 2.0), and thus structure information can be collected in regions of reciprocal space that are not accessable with other diffraction methods. LACBED intensities in this range can be utilized for determination of accurate temperature factors or for refinement of coordinates. Such high index reflections can usually be treated kinematically or as a pertubed two-beam case. Application to Y Ba2Cu3O7 shows that a least square refinememt based on integrated intensities can determine temperature factors or coordinates.LACBED patterns taken in the (00l) systematic row show an easily recognisable pattern of narrow bands from reflections in the range 15 < l < 40 (figure 1). Integrated intensities obtained from measured intensity profiles after subtraction of inelastic background (figure 2) were used in the least square fit for determination of temperature factors and refinement of z-coordinates for the Ba- and Cu-atoms.

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Biomedical applications: Pitfalls in the practice

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100169626 ◽

1994 ◽

Vol 52 ◽

pp. 378-379

Author(s):

J. D. Shelburne ◽

Peter Ingram ◽

Victor L. Roggli ◽

Ann LeFurgey

Keyword(s):

Operating Room ◽

Liquid Nitrogen ◽

Lung Tissue ◽

Biomedical Applications ◽

Microprobe Analysis ◽

Tissue Sample ◽

Cellular Level ◽

Tissue Samples ◽

Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

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