title: Synergistic extraction of cobalt (II) by beta hydroxy naphthaldoxime and neutral donors.
abstract: Liquid - liquid extraction of Cobalt (II) from aqueous hydrochloric acid medium by the use of oxime derivative of beta-hydroxy naphthaldehyde in o-xylene medium is being reported. The ligand was synthesized and characterized in our laboratory. The typical pH range of extraction of Co (II) by the ligand - donor combination was seen to be between 8 - 9. The effect of different donors like dimethyl sulphoxide (DMSO), trioctyl phosphine oxide (TOPO) and bis(2-ethylhexyl) phosphonate and the effect of various diluents on the extraction of Co(II) by the present method were studied in detail. The binary adduct formation constant (log kex) in the organic phase was found to be 3.182. The overall equilibrium constant (log K) for the ternary species [Co(A)(DMSO)(Cl)], [Co(A)(TOPO)(Cl)] and [Co(A)(phosphonate)(Cl)] were estimated to be 6.42, 6.22 and 6.25 respectively. The trend in equilibrium constants were in accordance with their basic character, i.e., (DMSO > or = TOPO approximately/= phosphonate). The results were extrapolated in the determination of Cobalt in pharmaceutical drugs and cobalt bearing ore samples.
authors.affiliation: Nuclear and Analytical Chemistry Laboratory, Department of Chemistry, The University of Burdwan, Golapbag, Burdwan - 713 104, India.
authors.forename: Shrabanti
authors.initials: S
authors.lastname: Banerjee
authors.forename: Sukalyan
authors.initials: S
authors.lastname: Basu
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002413:Cations, Divalent; D002623:Chemistry Techniques, Analytical / Q000379:methods; D003035:Cobalt / Q000737:chemistry / Q000302:isolation & purification*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D009284:Naphthols / Q000737:chemistry*; D063065:Organophosphonates / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry; D010091:Oximes / Q000138:chemical synthesis / Q000737:chemistry*; D013054:Spectrophotometry, Atomic
chemical_list: D000447:Aldehydes; D002413:Cations, Divalent; D009284:Naphthols; D063065:Organophosphonates; D009943:Organophosphorus Compounds; D010091:Oximes; D003035:Cobalt; C044965:trioctyl phosphine oxide; D004121:Dimethyl Sulfoxide