Abstract The high-resolution cpabilities of wavelenght-dispersive spectrometry can be profitably employed in the analysis of materials containing elements which cannot be early resolved by Si(Li) spectrometers. This situation frequently arises in cases where the concentration of an element must be determined in the presence of large quanities of neighboring elements. Additional advantages are associated with the ability to resolve the K α satellite groups arising from the high degree of multiple L-shell ionization produced when heavy ions are used. Recent investigations have shown that the intensity distribution of the K α satellites is quite sensitive to both the projectile energy and the chemical composition of the sample. This energy dependence provides a new method for measuring surface layer thicknesses. The dependence on chemical environment may prove to be utilizable for the chemical characterization of substances. Examples of each of the above applications are presented and discussed.