The gamma-radiolysis of HEDTA in a simulated, mixed waste

The -radiolysis of the parent compound N-(2-hydroxyethyl)ethylenediaminetriaceticacid (HEDTA) in a simulant of a Hanford mixed waste, at a -dose of7.5 . 10₆±10% R, yielded 94.4% degradation. HEDTA radiolysisyielded four degradation products: glyoxylic acid, N-( nitroso)iminodiaceticacid (NIDA) and 2 dicarboxylic acids, ethandioic (oxalic) and propandioic(malonic) acids. Glyoxylic acid had been identified in previous studies byour laboratory as N-hydroxymethyl-N-methyliminoacetic acid (HMMIA). Promptedby studies from another laboratory, the chelator fragment previously reportedby our laboratory as N-(methylamine)iminodiacetic acid (MAIDA) is re-identifiedas NIDA. A methylamine moiety previously believed to be present in MAIDA,and several other chelator fragments, as well, has been re-identified as anitroso group.