| With the rapid development of information age,a large amount of new technology has been emerged which promoting the development of modern industry.It is possible that novel environmental pollutant can be released into the environment along with the procedure of producing new materials or products.Those novel environmental pollutants consist of complex components,are difficult to be degraded and are bad for biodiversity.Nowadays,researchers are focus on developing novel analytical methods and instruments which help them make further understanding of toxicity mechanism of those environmental pollutants.Due to the various toxic effects and the increased environmental effects,the analysis of different pollutant from environmental samples,by a sensitive and fast analytic method,is of much importance.Capillary electrophoresis(CE)has been developed rapidly in recent years.Owing to the low sample consumption,rapid analysis and high separation efficiency,CE has become an effective and powerful tool in the separation of a large variety of compounds including charged and neutral compounds.Due to the ionization of silanol groups,the bare fused-silica capillary which is negative charged can be covalent or non-covalent coated with positive or neutral charged reagent to modify the EOF.The capillary can be modified with different kind of materials or chemicals to expand its application in analytical chemistry and obtain better separation efficiency.Ionic substances with melting points below 100? or near room temperature are often referred to as ionic liquid.As a novel "green solvent",ionic liquids(IL)present a variety of unique physicochemical properties,such as high thermal stable,negligible,nonvolatile and nonflammable,environment benignancy and can be applied in many research fields.Since the properties of ILs are mainly influenced by both their cationic and anionic moieties which could be designed and synthesized with different functional groups as we need,ILs are referred to as "tunable or tailor-made materials".In CE method,dynamic coatings as additives are becoming popular because they are easy to prepared and ILs modified capillary wall can enhance resolution,peak efficiency and peak symmetry.They are typically used as separation medium and coating reagents that can non-covalent bind to capillary wall to decrease the unwanted effects of free silanol and improve the separation efficiency.In this dissertation,a serials of fast and sensitive ionic liquids modified capillary electrophoresis with amperometric detection methods are developed.And it is proved that all those environmental pollutants can be separated and detected accurately.The optimum separation conditions are discussed,including the concentration of ionic liquids and other separation conditions.The interaction between the analyte,silanol groups and ionic liquids are also discussed.It affords a feasible strategy to design and select functional ILs as BGE additive with desired functions to improve the separation efficiency in CE.Those methods provide an efficient simultaneous analytical technique on a variety of environmental pollutants,and have good prospect of application.Chapter 1.introductionIn this chapter,the property of environmental pollutant,present pollution,sources,harm and the analysis methods are introduced.The development,the principle and the application of capillary electrophoresis are outlined.The procedure and the classification of capillary coating are also introduced.Chapter 2.?-cyclodextrin-ionic liquid polymer based dynamically coating for simultaneous determination of tetracyclines by capillary electrophoresisTetracyclines are a group of broad spectrum antibiotics widely used in animal husbandry to prevent and treat diseases.However,the improper use of tetracyclines may result in the presence of their residues in animal tissues or waste.Recently,great attention has been drawn towards the green solvents ionic liquids.Ionic liquids have been employed as coating material to modify the electroosmotic flow in capillary electrophoresis.In this study,a functionalized ionic liquid,mono-6-deoxy-6-(3-methylimidazolium)-?-cyclodextrin tosylate,was synthesized and used for the simultaneous separation and quantification of tetracyclines by capillary electrophoresis.Good separation efficiency could be achieved due to the multiple functions of ?-cyclodextrin derived ionic liquid,including the electrostatic,the hydrogen interaction,and the cavity structure in(3-cyclodextrin ionic liquid which can entrap the tetracyclines to form inclusion complex.After optimization,the optimum experimental separation condition consisted of 10 mmol/L,pH 7.2 phosphate buffer and 20 mmol/L P-cyclodextrin ionic liquid with baseline separation in 25 min.The satisfied result demonstrated that the ?-cyclodextrin ionic liquid is an ideal background electrolyte modifier in the separation of tetracyclines with high stability and good reproducibility.And it is an effective strategy to design and synthesize specific ILs as additive applied in separation.Chapter 3.Geminal dicationic ionic liquids dynamically coating for simultaneous determination of bisphenols by capillary electrophoresisBisphenols are widely used as raw material in industry for the production of plastics etc.Recently,great attention has been drawn towards the green solvents ionic liquids.And ionic liquids have been employed as coating material to modify the electroosmotic flow in capillary electrophoresis.In this chapter,a simple and fast capillary electrophoresis method were developed by using a kind of ammonium-based geminal dicationic ionic liquids which were synthesized and used according to the characteristics and interactions between ionic liquids and analytes.The separation efficiency was also affected by the bridging alkyl chain,so the interaction of geminal dicationic ionic liquids with different bridging alkyl chain were observed.And the result indicated that the geminal dicationic ionic liquids with longer alkyl can form a stronger and stable suppressed EOF which improve the separation efficiency.After optimizing the separation conditions,the optimum experimental separation condition consisted of 40 mmol/L,pH 10.0 Na2B4O7-NaOH solution and 3 mmol/L ammonium-based geminal dicationic ionic liquids with baseline separation in 20 min.The proposed method provides a simple and environmental friendly strategy to synthesize and choose specific ionic liquid as additive applied in separation.Chapter 4.quaternary ammonium-based ionic liquids dynamically coating for simultaneous determination of diuron by capillary electrophoresisDiuron and other herbicides are the most extensively type pesticide which has been frequently used in agriculture.Due to their limited biodegradability,high vapor pressure and high lipid affinity,they are considered a persistent class of chemicals.Because of its toxicity for aquatic organisms and humans,diuron is the object of growing environmental concern.In this chapter,a simple and fast capillary electrophoresis method were developed by using a kind of quaternary ammonium-based ionic liquids which were synthesized and used according to the characteristics and interactions between ionic liquids and analytes.And it is proven that the ionic liquid is an ideal background electrolyte modifier in the separation of diuron and other herbicides with high stability and good reproducibility.The proposed method also provides a prospect analytical strategy of environmental pollutant. |
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