Determination of elemental area concentration in ultrathin specimens by x-ray microanalysis and atomic absorption spectrophotometry

Chandler, J. A.; Morton, Michael S. Scott

doi:10.1021/ac50003a016

Cited by 7 publications

(6 citation statements)

References 18 publications

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“…The reproducibility of thickness determination was found to be better than + 7O, provided the probe was positioned further than 2 pm from the grid bar (Chandler & Morton, 1976). Fig.…”

Section: Analysis Of An Ultrathin Section Containing L O O Concentratmentioning

confidence: 87%

“…White radiation was measured by integration of the energy region 4070-7450 eV and corrections for spurious white radiation from surrounding metal parts (grid bars etc) were made as described by Chandler (1973) and Chandler & Morton (1976).…”

Section: (A) Calibration Standardsmentioning

confidence: 99%

“…A film of aluminium of approximate thickness 50 nm was evaporated in vacuo onto a filter paper on which were placed some carbon coated nylon grids (Agar Aids). The filter paper was cut up into measured squares, dissolved in acid and analysed in a Varian atomic absorption spectrometer for aluminium as described elsewhere (Chandler & Morton, 1976). The A1 films on nylon grids were then analysed for A~K , (peak minus background counts) to produce a count rate for a given beam current under set conditions in EMMA.…”

Section: (B) Specimen Thickness Measurementmentioning

confidence: 99%

“…The method is valid even for unsupported and uncoated sections since these factors would add to the total mass thickness of the specimen but not affect the section thickness. Measurements should be made at distances greater than 2 prn from the grid bars since scattered electrons produce spurious white radiation (Chandler & Morton, 1976). During an examination of a biological specimen, measurements would usually be made in areas of clear embeddment close to the regions of interest.…”

Section: (B) Specimen Thicknessmentioning

confidence: 99%

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A method for preparing absolute standards for quantitative calibration and measurement of section thickness with X‐ray microanalysis of biological ultrathin specimens in EMMA

Chandler

1976

Journal of Microscopy

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Specimen thickness is determined using X-ray microanalysis in conjunction with atomic absorption spectrophotometry. Specimens of evaporated metal films and standards comprising fixed concentrations of element (such as potassium) in organic media are used to determine elemental concentrations of endogenous elements in embedding resin, from which section thickness can also be determined. The method finally depends only on the single measurement of X-ray emission of such an element in the specimen. Calibration of the X-ray detector over the energy range with mineral salts enables the standard to be used for the quantitative analysis of any element under investigation.

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“…The reproducibility of thickness determination was found to be better than + 7O, provided the probe was positioned further than 2 pm from the grid bar (Chandler & Morton, 1976). Fig.…”

Section: Analysis Of An Ultrathin Section Containing L O O Concentratmentioning

confidence: 87%

Section: (A) Calibration Standardsmentioning

confidence: 99%

Section: (B) Specimen Thickness Measurementmentioning

confidence: 99%

Section: (B) Specimen Thicknessmentioning

confidence: 99%

See 2 more Smart Citations

A method for preparing absolute standards for quantitative calibration and measurement of section thickness with X‐ray microanalysis of biological ultrathin specimens in EMMA

Chandler

1976

Journal of Microscopy

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“…In the case of very thin specimens, as used for the transmission electron microscope, however, the analytical technique for bulk specimens cannot be employed simply. Several techniques have been developed primarily for the quantitative determination of elemental concentration in ultrathin specimens (Marshall and Hall, 1968;Namae, 1975;Chandler and Morton, 1976). Marshall and Hall (1968) showed the concentration of an element could be determined by the ratio of the intensity of the characteristic line to that of the continuous radiation from the same analyzing point.…”

Section: Discussionmentioning

confidence: 99%

Semiquantitative Chemical Analysis of Asbestos Fibers and Clay Minerals with an Analytical Electron Microscope

Hayashi

Aita

Suzuki

1978

Clays and clay miner.

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By using a transmission electron microscope equipped with an energy dispersive spectrometer, it Was possible to detect the morphological, structural, and chemical characteristics of individual asbestos fibers and clay minerals without any realignment of the equipment. A rapid and convenient procedure for semiquantitative analysis is proposed. Analyses are given for 21 hydrous silicates, asbestos and clay minerals, by both ordinary chemical and energy dispersive methods. The energy dispersive results were comparable to those obtained by chemical analysis. Application of this procedure to asbestos fibers proved this method to be practical and valid for characterization of asbestos in environmental and tissue samples.

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Impact of manganese on primary hippocampal neurons from rodents

et al. 2014

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Manganese-enhanced magnetic resonance imaging (MEMRI) is a powerful tool for in vivo tract tracing or functional imaging of the central nervous system. However Mn(2+) may be toxic at high levels. In this study, we addressed the impact of Mn(2+) on mouse hippocampal neurons (HN) and neuron-like N2a cells in culture, using several approaches. Both HN and N2a cells not exposed to exogenous MnCl2 were shown by synchrotron X-ray fluorescence to contain 5 mg/g Mn. Concentrations of Mn(2+) leading to 50% lethality (LC50) after 24 h of incubation were much higher for N2a cells (863 mM) than for HN (90 mM). The distribution of Mn(2+) in both cell types exposed to Mn(2+) concentrations below LC50 was perinuclear whereas that in cells exposed to concentrations above LC50 was more diffuse, suggesting an overloading of cell storage/detoxification capacity. In addition, Mn(2+) had a cell-type and dose-dependent impact on the total amount of intracellular P, Ca, Fe and Zn measured by synchrotron X-ray fluorescence. For HN neurons, immunofluorescence studies revealed that concentrations of Mn(2+) below LC50 shortened neuritic length and decreased mitochondria velocity after 24 h of incubation. Similar concentrations of Mn(2+) also facilitated the opening of the mitochondrial permeability transition pore in isolated mitochondria from rat brains. The sensitivity of primary HN to Mn(2+) demonstrated here supports their use as a relevant model to study Mn(2+) -induced neurotoxicity.

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Determination of elemental area concentration in ultrathin specimens by x-ray microanalysis and atomic absorption spectrophotometry

Cited by 7 publications

References 18 publications

A method for preparing absolute standards for quantitative calibration and measurement of section thickness with X‐ray microanalysis of biological ultrathin specimens in EMMA

A method for preparing absolute standards for quantitative calibration and measurement of section thickness with X‐ray microanalysis of biological ultrathin specimens in EMMA

Semiquantitative Chemical Analysis of Asbestos Fibers and Clay Minerals with an Analytical Electron Microscope

Impact of manganese on primary hippocampal neurons from rodents

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