The object of this paper is to present results of the following analyses: 1) Nondestructive determination of oxygen in silicon by alpha and proton activation, in iron and niobium by He activation; 2) Oxygen by gamma activation followed by a chemical separation of oxygen-15 by reducing fusion; 3) Carbon and nitrogen by gamma activation followed by a simultaneous separation of nitrogen-13 and carbon-11 by oxidizing fusion; and 4) Nitrogen by proton activation.