Deep Eutectic Solvents And Molecular Imprinted Polymers For Optimized Separation And Purification For Biological Ingredients

In this research,different types of deep eutectic solvents(DESs)were designed and synthesized and new molecules imprinted polymers(MIPs)with different small molecules as templates were prepared.Their properties were studied and combined with solid-phase extraction method for isolating and purifying of the active components from biologicals.This paper is divided into four chapters,including the following:The first chapter demonstrates the synthesis of DESs,synthesis and applications of new MIPs,and their combination with solid phase extraction methods for extraction and analysis of biological active components.The second chapter is concerning the applications of DESs in the mobile phase to optimize analysis of caffeic acid in high performance liquid chromatography(HPLC).Reaction temperature,molar ratio of glycerol and choline chloride,and volume percent of additives were investigated in BBD.Reaction temperature(80 °C),molar ratio of glycerol and ChC l(3:1,n/n),and volume percent of additive(0.10%,v/v)were studied as optimum experiment factors.The mean chromatographic theoretical plate number of the caffeic acid in this condition was 1567.5.It was proved that DESs as additives can effect theoretical plate number and improve column efficiency in HPLC.The third chapter is concerning choline chloride-based DESs for optimizing extraction of ferulic acid from wheat bran.The obtained DESs were used as solvents to optimize extraction of ferulic acid from wheat bran,and DES-2 was studied with the highest extraction yield.A 17-run BBD was employed to evaluate the best extractio n condition of DES with three factors such as volume fraction of DESs,ratio of liquid to materials,and extraction time.The optimum condition(volume fraction of DESs(50%),ratio of liquid to materials(15 ml·g-1),and extraction time(35 min))was obtained with the extraction yield of ferulic acid was 5.86 mg·g-1.The results showed DESs had potential as an alternative solvent for extraction of bioactive compounds from natural plants.The fourth chapter is concerning DESs combined with MIPs for purification of caffeic acid from hawthorn using solid-phase extraction(SPE)methods.MIPs,NIPs and C18 were used for rapid purification of caffeic acid from hawthorn with SPE,and extract yields of caffeic acid with the proposed materials were 3.46 μg·g-1,1.01 μg·g-1 and 1.17 μg·g-1,respectively.Methanol mixing with the two kinds of DESs in different volume ratios was used to as elution solutions in the above procedures of MIPs-SPE.It was showed that methanol/glycerol-based DESs had the best elution capability with the recovery of 82.32%,and MIPs have potentials as SPE materials.