Synthesis And Characterization Of New Tape Of Sulfobetaine-based Zwitterionic Hydrophilic Monolithic Columns And Its Evaluation In Capillary Chromatography

Hydrophilic interaction liquid chromatography(HILIC) has many specific advantagesover conventional normal phase liquid chromatography(NP-LC) and reversed phase liquidchromatography(RP-LC). For example, HILIC column is suitable for analyzing polarcompounds and can be conveniently coupled to mass spectrometry (MS) without usingexpensive ion pair reagents. Therefore, it has attracted much attention in recent years.Monolithic column has drawn considerable interests due to their low back pressure, highefficency and high diffusion mass transfer. And it has been successfully applied to theseparation of proteins, polypeptides and nucleic acid. With the advantages of HILIC andmonolithic column, hydrophilic monolithic column is the best choice for the separation ofpolar compounds, providing more options for the complex sample.The hydrophilic monolithic columns were prepared with{[3-(metharyloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxide inner salt(SPP)} as monomer,pentaerythritol triacrylate(PETA) and polyhedral oligomeric silsesquioxane(POSS) ascrosslinker, azobisisobutyronitrile(AIBN) as initiator. In order to optimize the properties,the contents of the polymerization mixture were investigated. The columns were used inpressurized capillary electrochromatography(pCEC) and capillary liquid chromatography(cLC) for the separation of a mixture of phenols, nucleosides and so on. At last, the poly(SPP-co-PETA-PEG&MeOH) was applied to analysis of maleic acids in starch.The thesis contains five chapters as follows:The first chapter introduced the basic theory of capillary electrochromatography andpressurized capillary electrochromatography. Further, it reviewed the theoretical researchand the overall progress of the monolithic column, which provided a theoretical basis andmethods for this project.The second chapter described the preparation, optimization and characteration of theorganic polymer monolith column poly(SPP-co-PETA-PEG&MeOH) in detail.Sulfobetaine-based capillary zwitterionic hydrophilic monolithic column was synthesizedwith a novel binary porogenic agent of polyethylene glycol (PEG)/methanol. The polymerwas prepared with SPP as monomer, PETA as crosslinker, AIBN as initiator. In order tooptimize the properties, the contents of the polymerization mixture were investigated. Theoptimum preparation conditions were as followed: monomer: porogenator(1:2.5);monomer(SPP:PETA=1:1); the binary porogenic agent(PEG:methanol=2:1); compositionof the initiator (AIBN) was0.1%. With the binary porogenic agent of PEG/methanoladdition, good mechanical stability, homogeneous column bed, good permeability andnarrow pore size distribution were obtained. Explored the retention mechanism ofhydrophilic monolithic column poly(SPP-co-PETA),it appears typical hydrophilicretention mechanism when the acetonitrile concentration is more than50%of the mobilephase.In chapter three, the column with the best proportion was used in cLC and pCEC forthe separation of a mixture of phenols, nucleosides and so on. When amine mixture wasused as sample, N, N-methylene-bis-acrylamide’s column efficiency reached240,000plate/m. Bisides, the sapration of8nucleosides mixture showed that pCEC can not onlyimprove the separation can also increase the separation speed compared to cLC.In chapter four, the column poly(SPP-co-PETA-PEG&MeOH) was applied to detectof maleic acid in the starch, using capillary liquid chromatography(cLC) mothod. And the result showed that the limits of detection (LODs)(S/N=3) for standard sample of maleicacid was0.001mg/mL, the calibration curve showed good linearity in the range of2μg/mL~500μg/mL for maleic acid, the correlation coefficient was0.9997, the recoverieswere96%~108%and relative standard deviation were2.8%~7.6%. The method is simple,accurate and works well without using the ion-pairing agent. The starch were analyzedquantitatively by cLC using this method. It is shown that this method is promising in theroutine analysis of starch.In the fifth chapter, the polymer was prepared with{[3-(metharyloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxide inner salt(SPP)} as monomer,Polyhedral oligomeric silsesquioxane(POSS) as crosslinker, azobisisobutyronitrile(AIBN)as initiator, using toluene, methanol and acetone as the porogenic agent. And the columnwith the best proportion was used in cLC, pCEC for the separation of a mixture of phenols,nucleosides and so on. The results showed that the hybrid monolithic column poly(SPP-co-POSS-MA) possessed satisfying mechanical stability, good peak symmetry, butpoor seperation ability compared to poly(SPP-co-PETA).