Micro analysis

For the more advanced student, we have extended the section on Quantitative Semi-micro Analysis, and we have included a section dealing with Special Techniques in Separation and Purification, namely Adsorption Chromatography, Paper Chromatography, and Ion- Exchange Processes. 

ELECTRON PROBE MICRO ANALYSIS OF THE METALLIC WARE OF THE BRONZE AGE... 

Crowe, D.E., Valley, J.W. and Baker, K.L. 1990 Micro-analysis of sulfur-isotope ratios and zona-tion by laser microprobe. Geochimica et CosmochimicaActa 54 2075-2092. 

Pitman, M.G., Lauchli, A. Stelzer (1981). Ion distribution in roots of barley seedlings as measured by electron probe X-ray micro-analysis. Plant Physiology, 66, 673-9. 

Molecular diffusion ( ) has been used in various ways in micro analysis. In Figure 27, is seen the Conway diffusion dish, in which the substance to be tested is placed on the outside, and the reagent is placed in the central cup. The cup is covered, and after a time, the substance being analyzed diffuses into the central cup where it produces an effect which can then be interpreted in various ways. In the Figure, carbon monoxide is being determined. This same method is very useful for alcohol determination, where dichromate oxidizes the alcohol after it diffuses into the dichromate from the blood. 

EPMA Solid Wide (Z > 4) Surface, imaging, micro-analysis 3... 

In a lOOkV TEM, useful specimens can range in thickness from 20nm to 0.5 pm. For micro analysis, the thinner the specimen the better the quality of the information that can generally be obtained. 

Biro, K. T., I. Pozsgai, and A. Vlader (1986), Electron beam micro-analysis of obsidian samples from geological and archaeological sites, Acta Archaeologica Academia Scientiarium Hungaricae 38, 257-278. 

Newbury, D. (1986), Advances in Scanning Electron Microscopy and X-Ray Micro Analysis, Plenum, New York. 

Analytical investigations usually concern samples which are temporally and locally invariant. This kind of analysis is denoted as bulk analysis (average analysis). On the other hand, analytical investigations can particularly be directed to characterize temporal or local dependences of the composition or structure of samples. One has to perform dynamic analysis or process analysis on the one hand and distribution analysis, local analysis, micro analysis, and nano analysis on the other. 

In a previous review of this topic (5), it was suggested that molecular distillation drying followed by resin embedding needed more work before it could be evaluated as a preparative technique for microanaly-tical work as there had only been one investigation that had used it (59). Unfortunately, as far as this author is aware, there has only been one more study (12) that has used the technique to prepare material for micro-analysis. It is possible that workers have been put off using it by the apparent fall from grace of the related freeze substitution technique or, more likely, by the expense of molecular distillation drying apparatus. 

Transmission electron microscopy pictures were taken using a JE0L 100 CX microscope. For some samples lateral micro-analysis of thin sections of zeolite was carried out using a HB-5 VG microscope equipped with EDX accessory at IFP (11). 

Jeffries, T. E., Pearce, N. J. G., Perkins, W.T., and Raith, A. (1996). Chemical fractionation during infrared and ultraviolet laser ablation inductively coupled plasma mass spectrometry - implications for mineral micro analysis. Analytical Communications 33 35-39. 

These methods are based on elution techniques, followed by micro-analysis of the resultant eluate by adopting one or more of the undermentioned known methods, namely ... 

Allen, T. Particle Size Measurement, Volumes 1 and 2. 5th edn. (Chapman and Hall, London, 1997) Beddow, J. K. Particle Characterization inTechnology, Vol I Application and. Micro-analysis, Vol 2 Morphological Analysis. (CRC Press, Boca Raton, FL, 1984)... 

Steele I. M., Hutcheon I. D. and Smith J. V. (1980b). Ion microprobe analysis of plagioclase feldspar (Cai xNaxAl2 xSi2+x08)- for major, minor and trace elements. VIII Int. Congr. X-ray Optics Micro analysis, Pendell Pub. Co, Midland, Michigan. 

Electron microprobe analyses were performed using a Cameca Camebax SX-100 at the Departamento de Geologia, Universidad de Oviedo, Spain. Operating conditions were a 15 to 20 kV accelerating voltage, beam current of 15 to 20 mA, and beam size of 1 to 2 pm. Natural standards were certificated by MAC (Micro Analysis... 

Center for Micro Analysis and Reaction Chemistry, University of Utah, Salt Lake City, UT 84112... 

Lahanier et al. Cited in Janssens K (2005) A survey of the recent use of X-ray beam methods for non-destructive investigations in the cultural heritage sector, Cultural Heritage Conservation and Environment Impact Assessment by Non-Destructive Testing and Micro-analysis, Van Grieken R, Janssens K (Eds) AA Balkema Publishers, London, pp. 265-308. 

Routine inorganic elemental analysis is carried out nowadays mainly by atomic spectrometric techniques based on the measurement of the energy of photons. The most frequently used photons for analytical atomic spectrometry extend from the ultraviolet (UV 190-390 nm) to the visible (Vis 390-750 nm) regions. Here the analyte must be in the form of atoms in the gas phase so that the photons interact easily with valence electrons. It is worth noting that techniques based on the measurement of X-rays emitted after excitation of the sample with X-rays i.e. X-ray fluorescence, XRF) or with energetic electrons (electron-probe X-ray micro-analysis, EPXMA) yield elemental information directly from solid samples, but they will not be explained here instead, they will be briefly treated in Section 1.5. 

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