Chemical Consequences of the Auger Effect: Iodine Yield from Iodoamino Acids as a Function of X-Ray Dose and Energy

Absorption of x-radiation in the iodothyronines results mainly in deiodination. G-values and dose effect curves were determined from 0.5 to 3.0 Mrads total absorbed dose for 3,5-diiodo-DL-thyronine, 3,5,3′-triiodo-DL-thyronine, and thyroxine. Radiation sensitivity increases with decreasing number of iodine atoms per molecule. Calculations based on I₂ yield measurements, as a function of maximum x-ray energy, indicate (after correction for radiation dose) that resonance absorption has a distinct effect upon the ensuing chemical transformation. This effect is stronger than would be predicted from published values of the K-to-L-shell Auger yields in iodine.