NOPR Collection:

Liquid-liquid extraction and separation of gallium(III) with Cyanex 921

Sun, 01 Oct 2000 00:00:00 GMT

Title: Liquid-liquid extraction and separation of gallium(III) with Cyanex 921 Authors: Mishra, B Y; Rokade, M D; Dhadke, P M Abstract: A simple and rapid method for the separation of gallium(III) from aqueous chloride media with tri-n-octylphosphine oxide (Cyanex 921) is described. Gallium(III) has been extracted with Cyanex 921 in toluene in the pH range 4.5-6.0 and stripped back with 2.0 M HNO₃. The effects of pH, equilibration period, diluents, diverse ion and stripping agents on the extraction of gallium(III) have been studied. The equilibrium constant and the thermodynamic parameters,ΔH, ΔS and ΔG have been evaluated. The method has been extended for binary and multicomponent separation of gallium(III). Page(s): 1114-1116

Ion-exchange properties of 8-hydroxyquinoline-biuret-formaldehyde tercopolymers

Sun, 01 Oct 2000 00:00:00 GMT

Title: Ion-exchange properties of 8-hydroxyquinoline-biuret-formaldehyde tercopolymers Authors: Gurnule, Wasudeo B; Juneja, H D; Paliwal, L J Abstract: Tercopolymer (8-HQBF) prepared by condensation of 8-hydroxyquinoline (8-HQ) and biuret (B) with formaldehyde (F) in the presence of 2M HCl as catalyst was proved to be a selective chelating ion-exchange tercopolymer for certain metals. Chelating ion-exchange properties of this tercopolymers are studied for Fe³⁺, Cu²⁺, Ni²⁺, Co²⁺, Zn²⁺, Cd²⁺ and Pb²⁺ ions. A batch equilibrium method has been employed in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study has been carried out over a wide pH range and in media of various ionic strengths. The polymer shows a higher selectivity for Fe³⁺, Cu²⁺ and Ni²⁺ ions than for Co²⁺, Zn²⁺, Cd²⁺ and Pb²⁺ ions. Page(s): 1110-1113

Spectrophotometric determination of vanadium(V) using methdilazine hydrochloride in minerals and steel samples

Sun, 01 Oct 2000 00:00:00 GMT

Title: Spectrophotometric determination of vanadium(V) using methdilazine hydrochloride in minerals and steel samples Authors: Melwanki, M B; Seetharamappa, J Abstract: Methdilazine hydrochloride has been used as a sensitive and selective reagent for the rapid spectrophotometric determination of vanadium(V). The reagent gives instantaneously a red coloured species on reaction with vanadium(V) in phosphoric acid medium and exhibits maximum absorbance at 512 nm with Sandell's sensitivity of 6.72 ng cm^-2. Beer's law is obeyed over the concentration range 0.2-5.4 ppm; the optimum concentration range is 0.5-5.0 ppm. The method has been successfully applied to the analysis of vanadium steels and minerals. Page(s): 1107-1109

Solvent extraction and spectrophotometric determination of Fe(II) with 1,3-diphenyl-4- carboethoxy pyrazole-5-one

Sun, 01 Oct 2000 00:00:00 GMT

Title: Solvent extraction and spectrophotometric determination of Fe(II) with 1,3-diphenyl-4- carboethoxy pyrazole-5-one Authors: Patil, R K; Dhuley, D G Abstract: A quick and selective method is developed for extractive spectrophotometric determination of Fe(II) using 1,3-diphenyl-4- carboethoxy pyrazole-5-one as the reagent. The wine-red coloured 1:3 (metal:ligand) complex in chloroform medium absorbs maximally at 525 nm. Beer's law is obeyed in the concentration range 0.5-10 μg/ml of Fe(II). The molar absorptivity and Sandell's sensitivity are found to be 1.156×10³1 mol^-1 cm^-1 and 0.0483 μgcm^-2 respectively. The effect of pH, equilibration time, reagent concentration and foreign ions have also been studied. The application of the method has been applied for the determination of Fe(II) in pharmaceutical samples. Page(s): 1105-1106