[en] Activation method is used to measure γ-ray absolute yields from thick targets for 54 elements. On the basis of these data potentialities of activation analysis of impurities with the help of nuclear reactions caused by 9.1 MeV protons are discussed. Values of absolute yields are presented. Nuclear reactions with above energy protons may be recommended to determine impurities of 26 of investigated elements. Experimental gamma spectra are presented for them. Results of investigations may be used in activation analysis of pure materials at solving problems of radioactive isotope accumulation and while evaluating radiation situation at proton accelerators