QUANTITATIVE CHEMICAL ANALYSIS BY X-RAY EMISSION SPECTROSCOPY

摘要

In X-ray emission spectrometry a quantitative chemical analysis of the elements in an unknown sample is obtained. A standard, or standards, whose composition has previously been accurately established is used to determine the first order approximation to the original intensity of the most efficient excitation energy for each element being determined. The most efficient excitation energy is defined as that energy which is just greater than the energy of the absorption edge of the characteristic X-ray emission line employed in the analysis. Using the computed original intensity of the most efficient excitation energy for each element in the standard(s), the observed X-ray intensities measured on the unknown, and an assumed chemical composition of the unknown, the expected characteristic X-ray intensity for each element in the unknown is computed. The assumed chemical composition of the unknown is then adjusted by a self-consistent iterative procedure until the expected and observed X-ray intensities for each element being determined agree. In this manner the best estimate of the chemical composition of the unknown is determined.