Synthesis of hydroxyiminodiacetic acid-chelating resin and the properties of adsorption and separation for rare earth metal ions

A chelating resin, containing N-2-hydroxypropyl-iminodiacetic acid (HIDA) as a functional group, was synthesized. The adsorption- and separation-behavior of the resin for tervalent rare earth metal ions have been studied. The chelating resin was prepared by the reaction of aminostyrene-divinylbenzene copolymer with N-3-chloro-2-hydroxypropyliminodiacetic acid at 90°C for 3 h. The chelating exchange capacity of the resin for Y(III) was about 1.5 meq/g resin on a dry weight basis. Relationship between distribution coefficient (Kd) and pH of the solution was as follows: the slope of log Kd-pH plot, 2 and metal/ligand, 1/2. The following separation factors on tervalent rare earth ions at pH 2 were obtained: Sc/La, 2088; Sc/Ce, 1480; Sc/Y, 776; Sc/Lu, 166; Lu/Y, 4.7; Lu/La, 13; Y/La, 2.7 and Ce/La, 1.4. After an appropriate amount of solution containing rare earth metal ions (pH 4) was added to the HIDA resin and stirred for 1 h, the resin was collected by filtration and dried. A weigh out portion of about 0.10.5 mg of resin was mixed with twenty fold of KBr. Rare earth metal ions on the resin was determined by FT-IR method, based on the decrease of spectrum strength for bending vibration of carboxylate ion (955 cm-1). This method is useful for the semiquantitative determination of rare earth metal ions. The procedure using the HIDA resin for the preconcentration of rare earth ions in monazite was established.