pH dependent separation of uranium by chelation chromatography using pyridine 2,6-dimethanol as a chelator: single crystal X-ray structural confirmation of the chelated uranium complex.
A very effective sorbent material which exhibits exceptional capture of hexavalent uranium from other actinides and lanthanides at microg g(-1) level, features pyridine 2,6-dimethanol immobilized onto alumina. The maximum sorption capacity for dioxouranium(VI) was found as 1.96 mmol g(-1) at pH 3.0. The adsorbed uranium complex was eluted completely by 0.05 mol L(-1) (NH(4))(2)CO(3) solution and the concentration of hexavalent dioxouranium ion was monitored spectrophotometrically using Arsenazo III. The structure of the chelated uranium complex has been confirmed by single crystal X-ray structure analysis and Fourier transform infrared red (FTIR) spectroscopy. Thermo gravimetric analysis/differential thermo gravimetric analysis (TGA/DTG) of the chelated uranium complex was performed. The method is reproducible with a relative standard deviation (RSD) of 1.2% (N=10) and the three sigma detection limits (N=15) 1.2 microg mL(-1) respectively. A pre-concentration factor, almost 500, for uranium was achieved. Interferences from Th(4+), Mn(2+), Ni(2+) and Cu(2+) ions were masked with ethylene diamine tetra acetic acid (di-sodium salt) (Na(2)EDTA) in the aqueous phase. The developed method has been tested for uranium recovery and estimation in some certified reference materials and environmental samples.
Department of Chemistry, The University of Burdwan, Burdwan, West Bengal, India.
Raja
R
Saha
Sudipta
S
Das
Arnab
A
Banerjee
Animesh
A
Sahana
M
M
Sudarsan
A M Z
AM
Slawin
Yang
Y
Li
Debasis
D
Das
D000537:Aluminum Oxide; D002614:Chelating Agents; D002845:Chromatography / Q000379:methods*; D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D014501:Uranium / Q000032:analysis / Q000302:isolation & purification* / Q000592:standards
C519068:2,6-bis-(hydroxymethyl)-pyridine; D002614:Chelating Agents; D011725:Pyridines; D014501:Uranium; D000537:Aluminum Oxide