Michaelis, R. E.
Chairman, National Bureau of Standards, Washington, D. C.,
Pages: 2 Published: Jan 1964
The main purpose of this summary covering the papers on X-ray Spectrochemical Analysis and the summary of the papers covering Electron Probe Analysis is to emphasize important points covered in the respective papers. The three papers that comprise the first session deal mainly with the basic instrumentation of X-ray spectrochemical analysis—production of X-rays, X-ray (and electron probe) optics, and X-ray detectors and counting techniques. The papers in the second session cover the applications of X-ray spectrochemical; analysis to metals and minerals, trace elements including thin films, and liquids and solutions. The first major point to be emphasized is that X-ray equipment has been developed and is commercially available to provide analysis of many materials. As is true of other analytical methods, however, X-ray spectrochemical methods have definite advantages and disadvantages, each of which must be evaluated fully with respect to the specific analytical problem. In view of the complexity associated with most analytical problems today, the analyst is finding it increasingly difficult to apply only one analytical technique to the solution of his problems. It is certain that the addition of X-ray spectrochemical equipment to a laboratory will enable the chemist to perform his analysis better. Absorption and enhancement effects (commonly referred to as interelement effects) offer the major source of difficulty in obtaining quantitative X-ray spectrochemical results. Most of the present papers touch on this subject and several corrective measures are described. It is pointed out that absorption effects that can be determined accurately with monochromatic X-rays can also be estimated fairly well with polychromatic X-ray excitation. Enhancement effects, however, are more difficult to evaluate and correction calculations can become quite complex.
Paper ID: STP45949S