Absorption and desorption behaviour of the total flavones from Glycyrrhiza residues on macroporous adsorption resins

The adsorption and desorption behaviours of macroporous resins for enriching total flavonoids from Glycyrrhiza residues were investigated.Five macroporous resins were studied using the static adsorption method.Additionally two representative resins( AB-8 and SP825) were chosen for adsorption thermodynamics and kinetics model studies,the conditions for purifying were optimized. The kinetics results showed that the whole adsorption process can be described better by the pseudo-second order kinetics model.The thermodynamics results showed that the adsorption process fited the Freundlich isothermal model,the adsorption of the representative resins was an exothermic and physical adsorption process. The optimum process conditions for purifying the total flavonoids from Glycyrrhiza residues using AB-8 resin were determined as follows: sample concentration of 1.089 mg / m L,flow velocity of 3 m L / min,sample volume of 2 BV,and amount of 80% ethanol as desorption solvent 3 BV,flow velocity of 1.5 m L / min. By this time the desorption rate was 91.67%. The purity was increased to 53.43%,which showed that AB-8 macroporou resin had better adsorption property. It can be used to purify and separate total flavonoids from Glycyrrhiza residues.