Purification Of Tea Saponin

Sasanquasaponins are the main outgrowth of sasanqua cakes. Sasanquasaponins are at low purification in the market at the present, which are widely used in pesticide trade, but limited in the trade of medicament and cosmetic. This paper with raw sasanquasaponin was purified by precipitation and reins chromatography, thereafter studied on kinetics and energetics of sasanquasaponin adsorption onto AB-8 resin.Saponin was purified by precipitation, and the impact factors were investigated. The results showed that the superior conditions of chemical precipitation optimum were solid/liquid ratio 1:20, 80% ethanol concentration, ethanol/acetone ratio 1:2. Under the optimized conditions the content of saponin in the product was 87.20%, the recovery of saponin was 71.17%.Factorial test results indicated that saponin purified by AB-8 resin was the best, 3.0mg/mL saponin at a feeding flow rate of 2.5mL/min for adsorption; 0.1% NaOH solution removed impurity; 90% ethanol at a flow rate of 2.0mL/min for desorption. The content of saponin in the product was 93.07%, while the recovery of saponin was 66.97%.The result of the kenetics of saponin adsorption on AB-8 showed that adsorption was well fitted to the feature of shrinking unreacted core model; the adsorption process of saponin onto AB-8 resin closely followed a pseudo-second-order kinetic model; outside diffusion, internal diffusion, adsorption equation were informed that internal diffusion was the main control step.The result of the thermodynamics of saponin adsorption on AB-8 showed that at the same concentration range, with the temperature of system increased, the adsorption capacity of saponin was increased,so the adsorption process was an endothermic process; Freundich and Langmuir models by fitting equation showed that the active sites on the surface of resin was uniformly distributed, and a preferential adsorption process, also an effective adsorption. Fitting with van't Hoff equation at different temperatures, the combined action of Van der Waals force and the hydrogen bonding may exist in the process of adsorption.