Abstract
This paper presents a split-standard technique for estimating the chemical yields of rapid two-step radiochemical separation procedures which have been applied to the Cu64 and Zn60m isotopes produced in 125 mg portions of dried human lung samples as the result of 30-minute irradiations in a thermal neutron flux of 1013 n/cm2-sec. The separated radioactivities were counted by using a 400-channel pulse-height analyzer and a 5-inch by 4-inch single NaI(Tl) crystal. The relative standard deviations for a set of five replicate determinations were 2.9% for copper and 5.7% for zinc.