STUDY OF THE SORPTION BEHAVIOR OF HIBISCUS SABDARIFFA ANTHOCYANINS ON A MACROPOROUS RESIN

摘要

The adsorption of Hibiscus sabdariffa sp. anthocyanins onto a macroporous resinnwas studied in laboratory experiments. The anthocyanin aqueous extractsnobtained from the calyces were used in agitated batch experiments with anmacroporous resin. The adsorption kinetics and isotherms of H. sabdariffa anthocyaninsnon a selected macroporous resin was studied to determine the parametersnthat have to be optimized to recover the anthocyanins from aqueous extracts ofnthe calyces. The adsorption kinetic experimental data were fit into a pseudonsecond order kinetic model, which was then used to determine several parametersnsuch as the contact time necessary to reach equilibrium as well as the maximumnadsorption capacity. The best fit for the equilibrium adsorption isotherm experimentalndata was obtained with the Langmuir isotherm model. Based on qualitativenand quantitative interpretation of the experimental data, the resin that wasntested here appeared to have good adsorption capacity for the anthocyanins evennthough the necessary time to reach equilibrium was particularly long.nThree aspects of the desorption of anthocyanins from the resin were studied:nthe speed of release of the anthocyanins (desorption kinetics), the extent of thenanthocyanin desorption depending on the adsorption contact time and finally, theninfluence of the mobile phase’s characteristics.