ANALYSIS AND QUANTIFICATION OF ORGANIC-ACIDS IN SIMULATED HANFORD TANK WASTE AND HANFORD TANK WASTE

Simulated Hanford tank waste samples were analyzed for organic acids b efore and after gamma-irradiation. Ion chromatography (IC) was used fo r the analysis for low-molecular-mass (LMM) organic acids and proved t o be an improvement over the previously used non-suppressed IC with ul traviolet (UV) detection method. Known quantities of sodium salts of e thylenediaminetetraacetic acid, N-(2-hydroxyethyl)ethylenediaminetriac etic acid, citric acid and glycolic acid were added to the tank waste simulants before exposure. The breakdown products of gamma-irradiated simulated tank waste samples included formic, succinic and oxalic acid s. These acids were identified and quantified using IC without any int erference from nitrates, nitrites, or any other inorganic anions in th e simulated waste. However, when non-suppressed IC with UV detection w as used, nitrates and nitrites were found to interfere with the quanti fication of LMM organic acids. Ion chromatography techniques were also used on actual Hanford tank waste to quantify and analyze LMM organic acids. These efforts will assist in understanding Hanford tank waste chemistry and improving the carbon balance of tank waste samples. (C) 1998 Elsevier Science B.V.