Synthesis Of Choline Amino Acid Ionic Liquid And Its Application In Separation And Analysis

The green ionic liquids is a kind of ionic liquid composed of biological cations and biological anions.Choline amino acid ionic liquid([Ch][AA])is synthesized by alkaloid choline(Ch)as cation and amino acid(AA)as anion Liquid,this type of ionic liquid is completely synthesized from biological materials,which has low toxicity and good biological affinity,and is regarded as a "green ionic liquid".In this paper,choline amino acid ionic liquid was synthesized,combined with double aqueous phase extraction and magnetic solid phase extraction,and applied to the separation analysis of target analytes.In section 2,a fast,sensitive,and environmentally friendly method was developed based on choline amino acid ionic liquids followed by amino acid ionic liquid aqueous two-phase extraction for the determination of sunset yellow in beverages using HPLC.It was found that the phase formation ability of[Ch][AA]-K3PO4 aqueous two-phase system was determined by the hydrophobicity of AA.The extraction conditions of the aqueous two-phase extraction of sunset yellow was optimized,a linear calibration curve was obtained within the range of 0.05-40.00 ?g·mL-1,with a detection limit of 0.021 ?g·mL-1,the precision was good(RSD<3.1%),the content of sunset yellow in the beverage sample was determined by the proposed method,and the result was satisfactory.In section 3,a novel method was developed based on choline amino acid ionic liquids followed by amino acid ionic liquid aqueous two-phase extraction for the determination of naphthalene and pyrene in water using synchronous fluorescence spectroscopy.The synchronous fluorescence detection conditions was optimized,determine the optimal ?? to make the fluorescence peaks of naphthalene and pyrene completely separate,which meet the requirements of analysis and determination.The linear ranges of the naphthalene and pyrene were 0.50-10.00 ?g·mL-1,0.05-5.00 ?g·mL-1,respectively.The proposed method was simple and fast,and the measurement results were satisfactory.In section 4,a magnetic solid-phase extraction sorbent was developed for preconcentration of allura red to their determination by HPLC.The sorbent was prepared by functionalizing choline proline ionic liquid on Fe3O4@SiO2.The optimised extraction procedure was composed of two steps:1)extraction condition(material dosage,pH,time,temperature,ionic strength,sample volume),2)elution conditions(eluent selection,dosage,time).A linear calibration curve was obtained in the range of 0.02-5.00 ?g·mL-1,with a detection limit of 9.0 ng·mL-1.The proposed method can be used for the extraction and pre-concentration of allura red in lipstick samples,and successfully measured by high-performance liquid chromatography,the results were satisfactory.In section 5,a magnetic solid-phase extraction sorbent(Fe3O4@SiO2@[Ch][Pro])was developed for preconcentration of Cr(?),Cu(?)and Pb(?)to their determination by ICP-OES.The optimised extraction procedure was composed of two steps:1)extraction condition(material dosage,pH,time,temperature,ionic strength,sample volume)2)elution conditions(eluent selection,dosage,time).The linearity and detection limits of the three metal ions are Cr(?)(10.0-200.0,0.20 ?g·L-1),Cu(?)(5.0-150.0,0.10 ?g·L-1),Pb(?)(10.0-200.0,0.20 ?g·L-1).Finally,this proposed method was successfully applied to the simultaneous determination of Cr(?),Cu(?)and Pb(?)in actual water samples,and the results were satisfactory.