Gas chromatographic study of complexing in the system hydrazoic acid-tributyl phosphate-nitric acid-uranyl nitrate

Elution gas chromatography has been used to study complexing of hydrazoic a cid with tributyl phosphate (TBP) in hexadecane solution in the presence of nitric acid and/or uranyl nitrate. The study covered the temperature range 298-338 K, with concentrations of either additive up to 0.41 mol dm(-3). T he results for hydrazoic acid elution at infinite dilution establish (a) th at stoichiometry of the TBP-HNO3 complex is 1:1 and (b) that both 2:1 and 1 :1 TBP-UO2(NO3)(2) complexes co-exist in the system, the latter increasing in amount as the temperature is raised. Both HNO3 and UO2(NO2)(2) act simpl y to reduce the amount of TBP free to form the 1:1 TBP-HN3 complex. Stabili ty constants for the equilibrium UO2(NO3)(2) TBP+TBP reversible arrow UO2(N O3)(2). 2TBP are presented. (C) 1999 Elsevier Science B.V. All rights reser ved.