Study On The Physicochemical Properties Of Pyrrolidine Bromide Aqueous Solution And Its Extraction Of L-tyrosine

As a new type of material,ionic liquids have attracted a lot of attention due to their excellent and unique physical and chemical properties,in line with the development direction of today's "green chemistry".Due to its unique "designability",ionic liquids are structurally modified to affect their physical and chemical properties,resulting in an ideal structure and properties.They are new green materials that can meet the specific needs of specific fields.Due to the unique properties of ionic liquids,ionic liquids have been widely used in the fields of organic synthesis,catalysis,electrochemistry,analytical chemistry,and extraction separation.However,the ionic liquid has a large viscosity at room temperature,and it is inconvenient to directly apply to production,and the application of its aqueous solution or organic solution can effectively solve this problem.Ionic liquid two-phase extraction as a new separation method in the field of extraction and separation of ionic liquids,effectively reducing the viscosity of ionic liquids,and because of its non-toxic,environmentally friendly,simple and efficient,recyclable characteristics Everyone's attention.The development of ionic liquids has broad prospects,and the application of its solutions as a new development direction has been valued by scholars at home and abroad.However,compared with pure ionic liquids,the physical and chemical properties of the solution are relatively small,which limits its application.Therefore,in this paper,the pyrrolidine bromide salt with optical properties was studied,and some physical and chemical properties of the aqueous solution were studied.The effect of alkyl functionalization on the thermodynamic properties of the ionic liquid aqueous solution was compared.The [C₃C₁PYR][Br]/K₂HPO₄ aqueous two-phase system was used to study the extraction performance of L-tyrosine,and the multi-factor analysis was carried out by response surface analysis,partial least squares method and CART regression tree.The main research contents are as follows:?1?N-propyl,N-methylpyrrolidine bromide?[C₃C₁PYR][Br]?and N-hydroxyethyl,N-,were measured at a standard atmospheric pressure in the temperature range of 288.15-318.15 K.The density,viscosity and refractive index of methylpyrrolidine bromide?[C₂OHC₁PYR][Br]?aqueous solution were calculated.Their apparent molar volume and relative viscosity were calculated.The infinite dilution at different temperatures was fitted according to the Redlich-Mayer equation.Apparent molar volume,and the apparent molar expansion coefficient of infinite dilution was obtained.Their relative viscosities were analyzed according to the Jones-Dole equation,and the viscosity B coefficient was obtained.The relationship between the refractive index of the system and the concentration was investigated.The effect of alkyl substituents on the above properties is discussed.?2?The extraction performance of [C₃C₁PYR][Br]/K₂HPO₄ aqueous two-phase system for L-tyrosine was studied.First,the imaging behavior of the system was determined by the cloud point method.Then,the effects of ionic liquid concentration,inorganic salt concentration,amino acid concentration,temperature and extraction time on the distribution behavior of L-tyrosine were investigated.?3?Three factors including ionic liquid concentration,inorganic salt concentration and amino acid concentration were selected by mathematical model for multi-factor analysis,and the effects of these three factors on extraction rate were studied.The response surface analysis method was used to explore the synergistic effect of the three factors on the extraction rate,and the optimal extraction conditions and maximum extraction rate were established.Regression models were established using partial least squares and CART regression trees,respectively,and the applicability of the two models to such problems was discussed.