Activation analysis of rare-earth elements used for measuring speed of passing through intestinal canal and measurement of passing-through speed

The rare-earth elements (La, Sm and Yb) used as the indexing substances for measuring the speed of passing through an intestinal canal were measured by activation analysis, and the effect that fecal matrices exert to the formation of calibration curves using standard substances was investigated. Yb-labeled feed was given to calves, the concentration in feces was measured by sampling with time lapse, and the passing-through speed was calculated and compared with the values by atomic absorption analysis. In the case of measuring the rare-earth elements within 30 hours after neutron irradiation, the effect of fecal matrices arose strongly, but in the measurement thereafter, the effect was small. The experiment of forming the calibration curves for measuring rare-earth elements by activation analysis was carried out by using La, Sm and Yb. The method of animal experiment is explained. In the spectrum by a multi-channel pulse height analyzer, La, Sm and Yb were separated as peaks, and by measuring the areas of peaks, the amounts of individual elements were able to be measured. The parameters of the speed of passing through intestinal canals are reported. (K.I.)