Construction Of Small Molecular Water-Miscible Alcohol-Salt Aqueous Two Phase Systems And Application On The Extraction Of Plant Pigment

Aqueous two-phase Extraction （Aqueous Two-Phase Extraction, ATPE） has becomingvery promising as a new separation technology in recent years. This method has advantagesof mild operating condition, safe non-toxic or low toxic and process simple, and it is verysuitable for industrial production. At present ATPE has been widely used in biologicalindustry, food industry, pharmaceutical industry and analysis of detection and other fields.Plant Pigments have advantage of high safety, and some one still have nutritional value andpharmacological effects, including antioxidant and free-radical effect, the maintenance ofthe effects on the cardiovascular system, antitumor, and protection of the genetic effect,therefore the natural Plant pigment is becoming more and more get the favour of consumer,demand is also increasing year by year. So the development and utilization of natural Plantpigment has become medicine, food and remarkable project in fine chemicals and otherfields.This topic constructs the hydrophilic small molecule alcohol-salt aqueous two-phasesystem, discussing the phase-septating ability of hydrophilic small molecules alcohol andsalt, laid a theoretical basis for the application of aqueous two-phase system.Ethanol-ammonium sulfate aqueous two-phase system is used to extract the anthocyaninsfrom bitter rose, realizing the separation of two effective components which is anthocyaninsand sugar; Ethanol-sodium hydroxide aqueous two-phase system is used to extract andsaponification chlorophyll in silkworm excrement, and further synthesized sodium copperchlorophyll. The main results were as follows:（1） Binodal data for ethanol,2-propanol and1-propanol+magnesium sulfate/zincsulfate+water systems were experimentally determined at （303.15and313.15） K,respectively. An empirical equation was used to correlate binodal data. The liquid-liquidequilibrium data for part of the investigated systems were obtained via the MATLAB. Inorder to evaluate the dependability of the calculation method and the tie-line data, theliquid-liquid equilibrium data were correlated by the Othmer-Tobias and Bancroft equations.The salting-out abilities of the investigated salts and the phase-forming abilities of theinvestigated hydrophilic alcohols were discussed by the effective excluded volume （EEV）of salt. The salting-out abilities of the investigated salts follow the order ZnSO₄> MgSO₄,which can be indicated by the location of the binodal curves plotted in molality and the salting-out coefficient. In addition, the phase-forming abilities of the investigatedhydrophilic alcohols follow the order:1-propanol>2-propanol> ethanol.（2） Binodal data for ethanol,2-propanol and1-propanol+sodium hydroxide+watersystems were experimentally determined at （283.15,298.15and313.15） K, respectively.An empirical equation was used to correlate the binodal data. On the basis of the empiricalequation with and the lever rule, the tie-lines data for the investigated systems at298.15Kwere obtained via the MATLAB and then correlated by Othmer-Tobias and Bancroftequations. Temperature and salt effects on this type of ATPS were investigated. It wasfound that an increase in temperature leads to an expansion of the two-phase area. Thesalting-out ability of NaF is stronger than that of NaOH. Additionally, the phase-formingabilities of the investigated hydrophilic alcohols were discussed by both the effectiveexcluded volume （EEV） of the investigated salt and the location of the binodal curves ofthe investigated systems. The phase-forming abilities of the investigated hydrophilicalcohols follow the order:1-propanol>2-propanol> ethanol.（3） Extraction of anthocyanins from bitter rose was carried out using anethanol-ammonium sulphate aqueous two-phase system （ATPS）. The effects of differentparameters such as salt concentration, ethanol concentration, temperature and pH on thepartition coefficient and recoveries of anthocyanins in the top system were studied.Furthermore, an experimental design of a three-level two-factor Box–Behnken designresponse surface methodology （RSM） was used to evaluate the influence of the greatfactors （salt concentration, ethanol concentration and temperature） on the partitionbehaviour of anthocyanins, and the optimal experimental concentration is obtained. Themaximum partition coefficients （5.64） and recoveries （78%） of anthocyanins in the topsystem within investigated range were obtained at22%（w/w） concentration of ammoniumsulphate,25%（w/w） concentration of ethanol, pH5and33.5℃.（4） Simultaneous aqueous two-phase extraction and saponification reaction ofchlorophyll from silkworm excrement was investigated in this study, and it was comparedwith the saponification reaction followed by aqueous two-phase extraction （ATPE） method.The results indicate that it is better to use the simultaneous aqueous two-phase extractionand saponification reaction method than other method. The effects of different parameterson the amount of sodium chlorophyllin in the top system of the ethanol-NaOH aqueoustwo-phase system （ATPS） were studied, including salt concentration, saponificationtemperature and time. When the NaOH concentration was0.4g/mL, saponificationtemperature and time were333.15K and2h respectively, the amount of sodium chlorophyllin in the top system reached its maximum in the investigated range. Further, thetop system of the ethanol-NaOH ATPS was taken out and used to prepare sodium copperchlorophyllin, and the absorbance ratio （A405.00nm/A627.00nm） was3.67.