ABSTRACT
Objective::To compare the adsorption characteristics of different macroporous adsorption resins for the total flavonoids in Epimedii Folium, clarify the adsorption mechanism, and screen the optimal resin for the purification of total flavonoids in Epimedii Folium. Method::Taking the adsorption and desorption capacities of the total flavonoids in Epimedii Folium and five representative flavonoids (epimedin A, epimendin B, epimendin C, icariin, baohuoside Ⅰ) as indexes, static adsorption and dynamic adsorption experiments were conducted to compare the adsorption characteristics of five macroporous including HPD100, HPD600, AB-8, X-5 and D101.The adsorption kinetics of the selected resin was studied by using the pseudo-first-order, pseudo-second-order kinetic models and intraparticle diffusion model, and the thermodynamic process was analyzed by using the Langmuir and Freundlich isothermal adsorption models, which explored the adsorption mechanism of resin from the perspective of physical chemistry. Result::HPD100 macroporous resin had a better adsorption and desorption properties than the others. The adsorption process of HPD100 macroporous resin for total flavonoids in Epimedii Folium and five representative flavonoids conformed to the pseudo-second-order kinetic model. The adsorption thermodynamic process of HPD100 resin for total flavonoids of Epimedii Folium conformed to the Freundlich model, and for the sum of five representative flavonoids conformed to the Langmuir model. The adsorption process of HPD100 resin for total flavonoids in Epimedii Folium was the exothermic process dominated by physical adsorption, and the optimal adsorption temperature was 25 ℃. Conclusion::HPD100 macroporous resin has large adsorption capacity, easy desorption and clear adsorption mechanism, it is suitable for isolation and purification of total flavonoids in Epimedii Folium.
ABSTRACT
Objective: To investigate the adsorption kinetics and thermodynamic characteristics of phenylethanoid glycosides (PGs) in the leaves of Callicarpa nudiflora on macroporous resins and provide a reference for the separation and purification of these compounds. Methods: With adsorption and desorption ratio as indexes, optimum types of macroporous resin for purification of PGs were selected from 8 kinds of macroporous resins by static adsorption and desorption tests, and then adsorption kinetics model and adsorption isotherm model of PGs were established to investigate their adsorption processes. Results: SP-825 and SP-207 resin were selected and they have similar adsorption process for PGs. Both of them showed a fast adsorption in 0-60 min, a slow adsorption in 60-360 min, and an equilibrium adsorption stage after 360 min. Adsorption dynamic behavior was well described by quasi-second-order equation of both SP-825 and SP-207 macroporous resins, and adsorption rate was mainly controlled by liquid film diffusion and intraparticle diffusion. Equilibrium adsorption data fitted Langmuir and Freundlich isotherm equations well. Both of the two kinds of resins showed good adsorption properties for PGs, and the adsorption process belongs to favorable adsorption. Conclusions: Both of the kinetic model and thermodynamic model can well describe the adsorption process of SP-825 and SP-207 macroporous resins and the two resins were regarded as excellent adsorption resins for the purification of PGs from the leaves of Callicarpa nudiflora.
ABSTRACT
Objective To confirm the synthesis conditions of Ganoderma lucidum Polysaccharide-Fe (Ⅲ) Complex, and study on adsorption kinetics of it.Methods Adopt alcohol sedimenting technique and decoloring, dialysis, etc, extracting refined polysaccharide from Ganoderma lucidum.The solution of the Polysaccharide with FeCl3 react in alkaline conditions.To synthesize the polysaccharide iron complexes(GPC).The iron contents were determined by o-phenanthroline spectrophotography and and study on adsorption kinetics of Ganoderma lucidum Polysaccharide-Fe (Ⅲ) Complex.Results GPC is red brown and shapeless powder,it's liable to dissove in water,its solution is neutral,without precipitation,dissociation and Fe3 +at the pH from 3 to 12,and insoluble in organic solvents.So GPC is very stable.At the same time under different temperatures, the Fe3 + and polysaccharide on the adsorption quantity of increased gradually over time, the basic stability after 1.5 h.At the same time, with different temperatures the adsorption quantity of polysaccharide Fe3 + increases with the rise of temperature.Conclusion GPC may become a new ideal oral iron.Time and temperature are the key fabrication processes of GPC.
ABSTRACT
AIM To fit the moisture adsorption models for Astragali Radix aqueous extract.METHODS For the aqueous extract prepared by decocting,the moisture adsorption kinetics curve and adsorption/desorption isotherms were drawn by gravimetry,and then the data on moisture adsorption were fitted.The fitted models were optimized according to evaluation indices of root mean square error (RMSE),residual sum of squares (RSS) and coefficient of determination (R2).RESULTS The double exponential model for moisture adsorption kinetics curve and Peleg model for adsorption/desorption isotherms were considered as the two best models with regard to their fitting effects (R2 values were the closest to 1,RMSE and RSS values were the closest to 0).Among them,various adsorption/desorption isotherms all belonged to type Ⅱ ("S" isotherm),while the higher equilibrium moisture content of desorption isotherm than that of adsorption isotherm contributed to obvious type H3 hysteresis phenomenon.CONCLUSION Double exponential model and Peleg model can well fit the moisture adsorption kinetics curve and adsorption/desorption isotherms of Astragali Radix aqueous extract,respectively.
ABSTRACT
This article was aimed to study macroporous resin adsorption kinetics for effective extraction of water ex-tracting with alcohol precipitating in cicada slough. PT, APTT and the coagulation-fibrinolysis dynamic figure were taken as main indexes, which were combined with static and dynamic tests, to select the best macroporous resin to separate and purify the extraction. Adsorption kinetics curve was drawn to fit the adsorption kinetics model. The re-sults showed that NKA-9 macroporous resin was more effective in separating and purifying effective extraction than others. The adsorption dynamic behavior was well described by the pseudo-second-order kinetics equation. It was concluded that the adsorption rate was mainly controlled by the intraparticle diffusion.
ABSTRACT
Objective: To investigate the purification technology of total flavonoids from the diaphragma of Juglans regia by macroporous resin. Methods: Twelve macroporous resins were chosn with static and dynamic adsorption and desorption experiments to optimize the purification parameters. Results: AB-8 macroporous resin was found to have good adsorption and desorption effects. The optimal purification conditions were pH value of 4.70, sample mass concentration of 0.713 5 mg/mL, the loaded amount of 4 mL/g, and loading flow rate of 1.5 BV/h. The sample was eluted by water with 2 BV and 50% ethanol of 2.5 BV, respectively. The purity of total flavonoids increased to 72.25% after the purification, and the yield was 93.94%. Conclusion: AB-8 is an ideal resin with the best enrichment for separating and purifying the total flavonoids from diaphragma of J. regia.
ABSTRACT
Objective To study the adsorption capability of chitosan(CTS)for Ni~(2+)in water.Methods The effects of different adsorption time(0-360 min),different temperature(25-60℃)and different initial pH value of the solution(4-8)on the adsorption were investigated.The adsorption kinetics and thermodynamics of CTS for Ni~(2+)in water were also studied and the IR of CTS and CTS-Ni~(2+)were determined.Results The maximal adsorption quantity could reach to 42.15 mg/g in the optimum condition that the temperature is 25℃,pH value was 7.0 and the adsorption time was 4 h.The adsorption kinetics showed that the pseudo-second-order equation was suitable for describing the adsorption of CTS for Ni~(2+)and the related correlation coefficients were more than 0.99.The calculated value of equilibrium adsorption quantity of Ni~(2+)was 45.05 mg/g.Study of adsorption thermodynamics showed that the linear regression equation of lnk and 1/T was lnk=-0.827 7/T+3.416 2,and the correlation coefficient was 0.998 9.The enthalpy change(△H~0)was 6.88 kJ/mol and the entropy change(△S~0)was 28.40 J/(mol?K).The IR showed that the coordination reaction occurred between-NH_2,-OH of CTS and Ni~(2+).Conclusion CTS can effectively remove Ni~(2+) in water.The adsorption of CTS for Ni~(2+)is spontaneous and endothermic.High temperature which is beneficial to the adsorption does not influence the adsorption quantity obviously.