Abstract

The partitioning of iodide was studied in an aqueous biphasic system (ABS) comprised of ammonium sulfate, polyethylene glycol (PEG), and water at 25°C. The average molecular weights of PEG were (2078, 3819, and 9887) g·mol-1. In a prior determination, data for the liquid-liquid equilibrium of this system were obtained and correlated with the nonrandom, two-liquid (NRTL) thermodynamic model. Data on the partition coefficients and percentage extraction of iodide were obtained , which were correlated as a function of the concentration gradient of the PEG between the phases and the average molecular weight of the PEG. The fit equation obtained had a mean deviation of 0.0171 and a mean error of 1.89 %. © 2007 American Chemical Society.