A Simplified Method for the Determination of Iodine131 in Milk

Open Access
Publisher Website
Google Scholar
Abstract
The method is based on gross gamma-counting of proteins obtained by trichloroacetic acid precipitation of milk preserved with formaldehyde. Formaldehyde favors a reaction where the inorganic form of I131 present in milk is transformed into protein-bound I131. The method is simple, accurate, and the results are comparable to those obtained by gamma spectrometric methods. It requires a shielded Nal crystal (thallium activated) with a photomultiplier assembly fed through a cathode follower and coupled directly to a decade scaler. The recovery of I131 is 98 [plus or minus] 2% and the presence of gamma-emitting K40, Cs137, and Ba140 + La140, usually found in milk has no effect on I131 determination.