Complex forming properties of ion exchange resins prepared from 8-hydroxyquinoline

Spectrophotometric determination of the second acid dissociation constant of oxine bound to controlled pore glass

“…The capacity of batch A was determined by the established literature method involving sorption of Cu2+ (7,11,19). In this experiment copper forms a 1:1 complex with bound 5-P-OXINE (5,19,22). The measured capacity was (3.6 ± 0.05) X 10"3 mmol of 5-P-OXINE/g.…”

“…concentration of free (hydrated) metal ion (e.g., Mn+) in the presence of its complexes (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). Measurements are made by the column equilibration technique in order to avoid perturbing the metal-ligand equilibria in the sample solution (7)(8)(9)(10)(11).…”

“…In the column equilibration experiment CPG-OXINE is first equilibrated with bulk solution containing Ca2+ with an activity oca and is then washed briefly with water to remove bulk solution from the pores and between the particles. The total number of moles of calcium remaining per gram of CPG-OXINE (ÑCa) is given by the expression ÑCa = [CiOX+]zVz + ñCa (5) where Vz is the volume per gram of CPG-OXINE in a thin layer of solution located at a distance x cm from the charge surface and [CaOX+]z is the concentration of complexed calcium in this thin layer of solution. The quantity ñca is the moles of dissolved calcium, not complexed by bound 5-P-OXINE, in the pores of CPG-OXINE that are not removed…”

“…Over the last 15 years there have been numerous literature reports on the preparation of sorbents by covalent binding of the ligand 8-hydroxyquinoline (oxine) to insoluble porous supports such as organic polymers (1)(2)(3)(4)(5), silica gel (6)(7)(8)(9)(10)(11)(12), and controlled pore glass (CPG) (7)(8)(9)(10)13,14). These sorbents are used to remove trace concentrations of heavy metal ions from electrolyte solutions (25), to preconcentrate trace metal ions prior to their quantitative determination (4, 6, 8, 14, [16][17][18] and as column packings for batch and chromatographic separations (2,3,12,13,19,20).…”