Electron probe analysis

Lauchli, A., Spurr, A.R. Wittkop, R.W. (1970). Electron probe analysis of freeze substituted, epoxy resin embedded tissue for ion transport studies in plants. Planta, 95, 341-50. 

In a study of dental silicate cements, Kent, Fletcher Wilson (1970) used electron probe analysis to study the fully set material. Their method of sample preparation varied slightly from the general one described above, in that they embedded their set cement in epoxy resin, polished the surface to flatness, and then coated it with a 2-nm carbon layer to provide electrical conductivity. They analysed the various areas of the cement for calcium, silicon, aluminium and phosphorus, and found that the cement comprised a matrix containing phosphorus, aluminium and calcium, but not silicon. The aluminosilicate glass was assumed to develop into a gel which was relatively depleted in calcium. 

Electron probe and X-ray fluorescence methods of analysis are used for rather different but complementary purposes. The ability to provide an elemental spot analysis is the important characteristic of electron probe methods, which thus find use in analytical problems where the composition of the specimen changes over short distances. The examination of the distribution of heavy metals within the cellular structure of biological specimens, the distribution of metal crystallites on the surface of heterogeneous catalysts, or the differences in composition in the region of surface irregularities and faults in alloys, are all important examples of this application. Figure 8.45 illustrates the analysis of parts of a biological cell just 1 pm apart. Combination of electron probe analysis with electron microscopy enables visual examination to be used to identify the areas of interest prior to the analytical measurement. 

Contrast the type of information obtainable in the determination of trace metals by X-ray fluorescence and electron probe analysis. 

HN03. ICP-AES showed a wide variety of elements to be present with a particular build-up of cobalt, nickel and zinc (50-100 ppm). The presence of lead, cadmium and mercury at dangerously high levels was not indicated. Additional qualitative studies were made by electron probe analysis and ICP-MS. 

Somlyo Regarding the nuclear envelope and Ca2+, there is an old picture in a book showing strontium in the nuclear envelope within the perinuclear space (Somlyo Somlyo 1975). The trouble is, when we load with calcium oxalate, we can get an egg shell of calcium oxalate around the nucleus, but when we do electron probe analysis under normal physiological conditions, there doesn t seem to be detectable Ca2+ in the nuclear space. However, this is probably because there is no calsequestrin or other Ca2+ binding protein present. 

Luttge U. Microautoradiography and Electron Probe Analysis Their Application to Plant Physiology, Springer-Verlag, New York, 1972. 

Domer P. Photometric methods in quantitative autoradiography, in Microautoradiography and Electron Probe Analysis. Their Application to Plant Physiology (Luttge U, ed.), Springer Verlag, New York, 1972, pp. 7M8. 

Gartner S, Le Faucheur L, Roinel N, Paris-Pireyre N. Preliminary studies on the elemental composition of xylem exudate from two varieties of wheat by electron probe analysis. Scanning Electron Microsc 1984 IV 1739-1744. 

Warner, R.R., Myers, M.C., and Taylor, D.A., Electron probe analysis of human skin. Determination of the water concentration profiles, J. Invest. Dermatol., 90, 218, 1988. 

G. Leon, C. Fiori, P. Das, M. Moreno, R. Tovar, J. L. Sanchez-Salas and M. L. Munoz (1997). Electron probe analysis and biochemical characterization of electron-dense granules secreted by Entamoeba histolytica. Mol. Biochem. Parasitol., 85, 233-242. 

CIO. Chambers, A., Hodgkinson, A., and Hornung, G., Electron probe analysis of small urinary tract calculi. Invest. Urol. 9, 376-384 (1972). 

Energy Dispersion X-Ray Analysis X-Ray and Electron Probe Analysis, ASTM STP 485. (Philadelphia American Society for Testing and Materials, 1971.)... 

J.W. Colby, "MAGIC IV, A Conputer Program for Quantitive Electron Microprobe Analysis, in Proceedings Sixth National Conference on Electron Probe Analysis, Pittsburgh (Electron Probe Analysis Society of America, 1971). 

Wet Chemical Analysis Electron Probe Analysis (Composite Sample), (>Single-Crystal),... 

N. Karlovac and D. A. Gedcke, Proceedings of the Eighth National Conference on Electron Probe Analysis, New Orleans, paper 17,1973. 

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