A new internal standard method for activation analysis and its application. Determination of Co,Ni, Rb,Sr in pepperbush by means of photon activation

A new internal standard method for activation analysis has been developed. This method is characterized by that a suitable element present originally in the sample is used as an internal standard and the comparative standard is prepared by applying the standard addition method to the duplicated sample. When a sample under examination contains W_ag of trace element A to be determined together with a known amount of element B which is usable as an internal standard, and when the comparative standard is prepared by adding W _a ^* g of accurately known small amount of the element A to the duplicated sample, even if the sample and comparative standard are irradiated separately by particles with different fluxes, W_a can be determined, easily by using the following equation: W_a=W _a ^* /(A _R ^* /A_R)-1] Where A_R and A _R ^* are counting ratios of gamma-rays emitted by two radioactive nuclides produced from the element A and B in the sample and comparative standard, respectively. Neither correction of the inhomogeneities of flux between the sample and comparative standard, nor that of, the self-shielding effects are necessary for the present method. The usefulness of the method was examined through the determination of Co, Ni, Rb and Sr in pepperbush by means of photon activation, and the precision and accuracy of the method were proved to be valid.