Complexing properties of alpha-isosaccharinate: thorium

The complexation of Th with alpha-isosaccharinate has been studied using liquid-liquid-extraction techniques. An organic phase consisting of 0.025 M acetylacetone in toluene was used with a 1.0 M NaClO4 aqueous phase kept at pH 8 in a thermostated AKUFVE unit at 25 degrees C. The concentration of a-isosaccharinate (ISA-) in the aqueous phase was incrementally increased and samples of equal volumes were taken from the two phases and analyzed in a liquid scintillation detector. Stability constants, beta(')(p), for the complexation reaction Th4+ + pISA(-) <-> Th (ISA)(p), were determined to be log beta(25 degrees C)(1) = 12.56 +/- 5.01, log beta(25 degrees C)(2) 19.38 +/- 0.35/ -0.95, and log beta(25 degrees C)(3) = 21.30 +/- 0.26.