SIMULTANEOUS DETERMINATION OF 59FE, 51CR, AND 125I, USING A GAMMA SPECTROMETER
Rept. for Oct 67-Jan 68,
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX
Pagination or Media Count:
In scintillation spectrometry, there are methods for separating 59Fe from 51Cr activity, and 51Cr from 125I activity, but no standard method has been presented for the simultaneous measurement of 59Fe, 51Cr, and 125I. In this study, a well-type scintillation spectrometer and discriminator were used to determine the activity of these three isotopes in one sample. The procedure is based on the use of contributory factors which remain constant and can be used in the calculation of various blood parameters. The mixed sample was counted at each of three previously determined settings and corrected for background. Then, the net 59Fe count equaled the total count at the 59Fe setting the net 51Cr count equaled 10 of the count at the 59Fe setting subtracted from the count at the 51Cr setting and the net 125I count equaled the sum of 7.5 of the net 59Fe count plus 7.0 of the net 51Cr count subtracted from the count at the 125I setting. The method can be used to separate the activity of any group of three or more gamma-emitting isotopes if their energy peaks are well separated.