PHOTON AND PROTON ACTIVATION-ANALYSIS OF IRON AND STEEL STANDARDS USING THE INTERNAL STANDARD METHOD COUPLED WITH THE STANDARD ADDITION METHOD

The internal standard method coupled with the standard addition method has been applied to photon activation analysis and proton activation analysis of minor elements and trace impurities in various types of ir on and steel samples issued by the Iron and Steel Institute of Japan ( ISIJ). Samples and standard addition samples were once dissolved to mi x homogeneously, an internal standard and elements to be determined an d solidified as a silica-gel to make a similar matrix composition and geometry. Cerium and yttrium were used as an internal standard in phot on and proton activation, respectively. In photon activation, 20 MeV e lectron beam was used for bremsstrahlung irradiation to reduce matrix activity and nuclear interference reactions, and the results were comp ared with those of 30 MeV irradiation. In proton activation, iron was removed by the MIBK extraction method after dissolving samples to redu ce the radioactivity of Co-56 from iron via Fe-56(p,n)Co-56 reaction. The results of proton and photon activation analysis were in good agre ement with the standard values of ISIJ.