The possibility of using high-energy ion beams for analytical purposes is explored. The most promising field is the identification of medium-weight elements by detection of K X-rays following alpha-particle and proton bombardment, where a sensitivity well bellow 1 ppm was predicted. In the case of heavy elements, interferences are possible because of competition of nuclear reactions. In the case of rare earths, the method is interference free, quantities of 0.1 mg/cm2 can be determined.