Neutron activation analysis (NAA) offers excellent sensitivities that are superior to other analytical techniques in performing identification and quantitative elemental analysis. The method involves the irradiation of samples and the detection of gamma energies emitted from the isotopes formed from the process of neutron capture. Most NAA were done by comparison method, which is found to have high errors due to the differences in the matrix composition of sample as well as comparator. The purpose of this study is to demonstrate an alternative technique of activation analysis based on absolute gamma ray measurements and the direct calculation of elemental concentrations from reaction rates equation of neutron capture process. The neutron spectrum parameters (f and a), thermal and epithermal neutron flux (fth, fepi,) at 4 rotary rack irradiation positions of the 1-MW Reaktor TRIGA PUSPATI were determined. The accuracy and precision of this technique were verified by analyzing two standard reference materials provided by IAEA, ie Soil-1 and Soil-7 at reactor irradiation position 10. The experimental results obtained for both the materials were found to be in good agreement with the certified values. Signified by the average z-score for the concentration values were below 2 for most elements. In conclusion, the proposed technique can be applied for many of our future activation analyses with high accuracy without having to rely on the availability of comparator multielement standards.