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.
Saha
Raja
R
Department of Chemistry, The University of Burdwan, Burdwan, West Bengal, India.
Das
Sudipta
S
Banerjee
Arnab
A
Sahana
Animesh
A
Sudarsan
M
M
Slawin
A M Z
AM
Li
Yang
Y
Das
Debasis
D
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