Interaction of uranium(VI) with phthalic acid.
Phthalic acid, a ubiquitous organic compound found in soil, water, and in domestic and nuclear wastes can affect the mobility and bioavailability of metals and radionuclides. We examined the complexation of uranium with phthalic acid by potentiometric titration, electrospray ionization-mass spectroscopy (ESI-MS), and extended X-ray absorption fine structure (EXAFS) analysis. Potentiometric titration of a 1:1 U/phthalic acid indicated uranyl ion bonding with both carboxylate groups of phthalic acid; above pH 5 the uranyl ion underwent hydrolysis with one hydroxyl group coordinated to the inner-sphere of uranium. In the presence of excess phthalic acid, ESI-MS analysis revealed the formation of both 1:1 and 1:2 U/phthalic acid complexes. EXAFS studies confirmed the mononuclear biligand 1:2 U/phthalic acid complex as the predominant form. These results show that phthalates can form soluble stable complexes with uranium and may affect its mobility.
Environmental Sciences Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
Gustavo J
GJ
Vazquez
Cleveland J
CJ
Dodge
Arokiasamy J
AJ
Francis
D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010795:Phthalic Acids / Q000737:chemistry*; D011199:Potentiometry / Q000379:methods; D012995:Solubility; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013052:Spectrometry, X-Ray Emission / Q000379:methods; D014501:Uranium / Q000737:chemistry*
D009942:Organometallic Compounds; D010795:Phthalic Acids; D014501:Uranium; C032279:phthalic acid