Decontamination of radioactive cesium from natural NaCl by amide-type open-chain crown ethers

An attempt has been made to develop a radiochemical methodology for the decontamination of a trace amount of radioactive cesium from a bulk amount of natural NaCl by liquid-liquid extraction (LLX). Open chain crown ethers, of amide type, namely, N,N,N',N'-tetraphenyl-3,6-dioxaoctanediamide (TDD), N,N,N',N'-tetraphenyl-3,6,9-trioxaundecanediamide and N,N'-dinaphthyl-N,N'-diphenyl-3,6-dioxaoctanediamide (DDD) have been chosen for this purpose. The separation factor between Cs and Na is the highest when 10(-4)M TDD dissolved in nitrobenzene is used as extractant and 0.4M picric acid at pH 5.0 is used as aqueous phase. About 60% Cs is extracted in this condition in a single run.