title: Solid phase extraction, separation and preconcentration of rare elements thorium(IV), uranium(VI), zirconium(IV), cerium(IV) and chromium(III) amid several other foreign ions with eriochrome black T anchored to 3-D networking silica gel.
abstract: The present work reports the systematic studies on extraction, separation and preconcentration of Th(IV), U(VI), Zr(IV), Ce(IV) and Cr(III) amid several other foreign ions using EBT anchored {SiO2}n3-D microarray. The effect of various sorption parameters, such as pH, concentration, temperature, sample volume, flow-rate and co-existing foreign ions were investigated. Quantitative sorption was ensured at solution pH: 6.0-6.5 for Th(IV), Ce(IV), Cr(III) and pH: 2.75-3.0 for Zr(IV), U(VI) couple. Analysis on extracted species and extraction sites reveals that [Th4(μ(2)-OH)8(H2O)4](8+), [Ce6(μ(2)-OH)12(H2O)5](12+), [Cr3(μ(2)-OH)4(H2O)](5+), [(UO2)3(μ(2)-OH)5(H2O)3](+) and [Zr4(μ(2)-OH)8(H2O)0.5](8+) for the respective metal ions gets extracted at HOMO of the extractor. HOMO-{metal ion species} was found to be 1:1 complexation. Sorption was endothermic, entropy-gaining, instantaneous and spontaneous in nature. A density functional theory (DFT) calculation has been performed to analyze the 3-D structure and electronic distribution of the synthesized extractor.
authors.affiliation: Analytical Laboratory, Department of Chemistry, Visva-Bharati Santiniketan, 731235, India.
authors.forename: Bhavya
authors.initials: B
authors.lastname: Srivastava
authors.affiliation: Analytical Laboratory, Department of Chemistry, Visva-Bharati Santiniketan, 731235, India.
authors.forename: Milan K
authors.initials: MK
authors.lastname: Barman
authors.affiliation: Analytical Laboratory, Department of Chemistry, Visva-Bharati Santiniketan, 731235, India.
authors.forename: Mousumi
authors.initials: M
authors.lastname: Chatterjee
authors.affiliation: Analytical Laboratory, Department of Chemistry, Visva-Bharati Santiniketan, 731235, India.
authors.forename: Dipika
authors.initials: D
authors.lastname: Roy
authors.affiliation: Analytical Laboratory, Department of Chemistry, Visva-Bharati Santiniketan, 731235, India. Electronic address: bhabatosh_mandal@yahoo.co.in.
authors.forename: Bhabatosh
authors.initials: B
authors.lastname: Mandal
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D002563:Cerium / Q000737:chemistry / Q000302:isolation & purification*; D002857:Chromium / Q000737:chemistry / Q000302:isolation & purification*; D007477:Ions / Q000737:chemistry / Q000302:isolation & purification; D058428:Silica Gel / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D052616:Solid Phase Extraction; D013910:Thorium / Q000737:chemistry / Q000302:isolation & purification*; D014501:Uranium / Q000737:chemistry / Q000302:isolation & purification*; D015040:Zirconium / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D001391:Azo Compounds; D007477:Ions; D002857:Chromium; D002563:Cerium; D014501:Uranium; D058428:Silica Gel; D013910:Thorium; D012822:Silicon Dioxide; D015040:Zirconium; C014527:Eriochrome Black T
keywords: Break-through capacity is a function of frontier orbitals; EBT anchored {SiO(2)}(n) 3-D microarray; HOMO-{metal ion species} 1:1 complexation; Sequential separation of Th(IV), Ce(IV), Cr(III), Zr(IV), U(VI); Solid phase extraction