The Process Study Of The Extraction Of Ginkgo Bilobal With Ionic Liquids

With high medicinal value,the flavonoids have been widely applied as a natural products.Ginkgo leaves contain lots of flavonoids.It's a very far-reaching significance to make full use of resources and development of ginkgo biloba.Ionic liquids?ILs?are low temperature molten salts which are made of an organic cation and an organic or inorganic anion and are liquid at room temperature or near room temperature.ILs have more advantages than conventional volatile organic solvent such as more environmental,lower toxicity.Through the relevant experimental study,this experiment chooses the ionic liquid extraction as the main agent to find the green,low cost,efficient and sustainable development of flavonoids extraction process.Taking ginkgo biloba as the research object,this article selects rutin as standard material,uses FT-IR for analysis,uses NaNO₂-Al?NO₃?₃-NaOH complex spectrophotometry to measure total flavonoids content in ginkgo biloba.Measurement wavelength of UV spectrophotometry:?=510 nm;the relationship of absorbance and concentration:A=0.4997c+0.0312;the linear correlation coefficient:R=0.999.This paper first studied the extraction process of flavonoids in ginkgo leaves using ionic liquids microwave-assisted combined with aqueous two-phase techniques in older to find the green pollution-free and efficient process for extraction of flavonoids in Ginkgo biloba.The impact of[Bmim]BF₄,NaH₂PO₄ aqueous two-phase systems,microwave test to samples is analyzed.Wherein the best extractant for ionic liquid is[Bmim]BF₄.By single factor experiments and orthogonal experiments,the optimum extraction conditions can be found:0.4 g/mL[Bmim]BF₄ as extractant,8 minutes'microwave extraction,500 W microwave power,ginkgo biloba sample liquid and extraction solvent's ratio:1:15 g/mL.On this condition,extractable amount of flavonoids is 32.72±0.13 mg/g?mean and standard deviation of three experiments?;the best aqueous two-phase system is[Bmim]BF₄-NaH₂PO_4;the maximum relative extraction efficiency of flavonoids is 93%.For[Bmim]BF₄-NaH₂PO₄,two-phase are analyzed and measured its phase equilibrium data under 20?.By FT-IR analysis of the microwave treatment ginkgo leaf samples before and after the microwave can be seen that microwaves can better improve the extraction efficiency but does not destroy the structure of some of the active ingredient.In order to find the best process for ionic liquid phase separation and purification flavonoids and reduce process costs,we studied the ion liquid phase flavonoids by macroporous resin separation and purification process,the recovering performance of macroporous resin and ionic liquids.The best ion liquid resin adsorption for flavonoids is D140;by single factor experiments and orthogonal experiments,the optimum conditions for separation and purification as follows:the pH of leach solution is 4.10;the content of leaching solution flavonoid is 0.25 mg/mL;leaching temperature is 40?;Leaching time is60 min.Under this conditions,extractable amount of flavonoids is 4.82±0.13 mg/g?mean and standard deviation of three experiments?;the leaching rate is 96.4%?macroporous resin and liquid sample liquid ratio is 1:20 g/mL?.The best desorption conditions of D140macroporous resin as follows:use 1.5 cm×20 cm glass column dynamic desorption;temperature controlled at 50±1?;Eluent ethanol concentration is 80%;the amount of eluent is 6 BV;wash off flow rate is 2BV/h,desorption rate is 83%.FT-IR analysis and the purity of the product were measured.It can be found that the resulting product is flavonoids and the average purity is 30.52%.Within 10 cycles,D140 macroporous resin and ionic liquids have good repeat performance.