“…Numerous uranyl-citrate complexes have been proposed in the literature: a 1:1 uranyl-citrate complex (Newman et al, 1951;Rajan and Martell, 1965;Markovits et al, 1972;Nunes and Gil, 1987;Lenhart et al, 2000), a 2:1 complex (Nunes and Gil, 1987), a 2:2 complex (Newman et al, 1951;Feldman et al, 1954;Rajan and Martell, 1965;Markovits et al, 1972;Nunes and Gil, 1987;Allen et al, 1996), a 2:3 complex (Dodge and Francis, 1997), a 3:2 complex (Feldman et al, 1954) and a hexameric complex (Rajan and Martell, 1965). In our speciation calculations, we consider only the complexes for which a formation constant exists: the mononuclear (1:1) and binuclear (2:2) complexes.…”