Equilibriam Of Licorice-Water System Under Ultrasound Conditions Using Adsorption Theory

The main medicinal ingredient of licoriceis Licorice acid; As people’s awareness of the health care with licorice strengthening,and the demand for licorice growing, so we need to explore new methods for the depth of the development and utilization of licorice.During the extraction of glycyrrhizin in licorice, choosing water as solvent and using the method of ultrasound-assisted extraction, experimental results show that: the use of this technology in the extraction of glycyrrhizin licorice, significantly reducing the leaching of glycyrrhizin equilibrium time, to achieve the effective extraction of glycyrrhizin and improve the effective utilization of glycyrrhizin. Therefore, the selection of ultrasound technology to study the leaching of glycyrrhizin has an important significance.We carried out a kinetic study ofextraction glycyrrhizin in licorice with water as solvent and ultrasound-assisted extraction technology.Then used calorimetric method to measure sound power of different frequencies.And the chang of equilibrium concentration of glycyrrhizin over time was contrast with mechanical agitation and ultrasonic extraction conditions. Experimental results indicated that during isothermal leaching process we found that under the ultrasound condition the equilibrium time for glycyrrhizin leaching obviously shortened, and the equilibrium concentration increased at the same time. Under isothermal licorice acid leaching reached balance by mechanical agitation, and then applied ultrasound,the equilibrium concentration of glycyrrhizic acid raised.The effects of solid-liquid ratio, particle size, temperature and ultrasonic conditions and other factors on the equilibrium concentration of glycyrrhizin was investigated.The optimum leaching conditions were that liquid ratio was 10:400 g/mL, the particle size was 7.79μm , the temperature was 30 ℃, and ultrasonic conditions was 20kHz.Under the optimum condition,the equilibrium concentration of glycyrrhizic acid was 3.574mg/mL.The leaching rate of glycyrrhizin reached to 87.2%.The leaching equilibrium model, which could be used for the simulation of licorice acid leaching balance, was discussed. Langmuir and Freundlich empirical equation were used to fitthe leaching balance data of licorice acid in this papar.The results showed that the leaching of glycyrrhizin was in accordance with the hypothesis of monolayer adsorption theory.ce/qe-ce hadshown an obvious linear relationship by fitted with the Langmuir equation.After comparing the R2,which were obtained by two methods,we could see that it was more appropriate to choose Langmuir equation for fitting the leaching balance of glycyrrhizin.