Preparation Of Novel COFs Coated Capillary And Application On Separation And Detection Of EEDs By CEC

Covalent organic framework?COFs?are a class of novel porous crystalline materials that are farmed through connecting building units containing light-weight elements such as C,H,O,and B by covalent bonding.The stable framework structure,large specific surface area,adjustable pore size and good stability of COFs provide a good structure basis for its application in chromatographic separation.Capillary electrochromatography?CEC?combines the excellent separation efficiency of capillary electrophoresis with good selectivity of high performance liquid chromatography and has been widely used for separation and analysis of various analytes.Environmental endocrine disruptors?EEDs?are a type of exogenous compounds that adversely affect the human endocrine and reproductive systems.Considering the structural characteristics of COFs,the separation mechanism of CEC and the importance of detecting EEDs,based on the previous work,the following researches were carried out around the preparation of new type COFs coated capillaries and their applications in CEC separation and detection of EEDs in this dissertation:?1?An ACOF-1 coated capillary was prepared by covalent bonding,and a new method of open tubular CEC?OT-CEC?for the separation of nitrophenols with the ACOF-1 coated capillary as separation channel was developed.The separation mechanism was also investigated.?2?N₀-COF coated capillary was prepared using N₀-COF as OT-CEC coating material by covalent bonding.And a new method for the separation of bisphenol fluorene and its structural analogs was established.And the corresponding separation mechanism was studied.?3?A new OT-CEC method for the separation and detection of bisphenol A and its analogues was established using N₀-COF coated capillary as separation channel.The separation mechanism was researched and the method was applied to detect bisphenol A and its analogues in plastic bottled beverages.This dissertation consists of five chapters.Chapter 1:Introduced and reviewed EEDs,their separation and detection methods;the classification of CEC columns and CEC stationary phase materials;the types,synthesis methods of COFs and their applications in chromatographic separation.Chapter 2:An ACOF-1 coated capillary was prepared using ACOF-1?a 2D azine-linked COF?as coating material for the first time.On this basis,a new OT-CEC method for the separation of nitrophenols was developed using ACOF-1 coated capillary as separation channel.Under optimal conditions,baseline separation of four nitrophenols analytes was successfully achieved.The prepared ACOF-1 coated capillary had good reproducibility and stability.The relative standard deviations?RSDs?of intra-day,inter-day and column-to-column of migration time and peak area were 1.39-1.51%,0.57-1.56%;5.66-6.77%,2.51-7.03%;3.65-5.46%,3.49-9.39%,respectively.And the ACOF-1 coated capillary could ensure better separation performance after 120 consecutive runs.The results of mechanistic study indicated that the size selectivity was the main factors affecting separation.Chapter 3:A N₀-COF coated capillary was prepared by using N₀-COF as coating material for the first time.And an OT-CEC method for the separation of bisphenol fluorene and its structural analog was established.Under optimal conditions,the established method enabled baseline separation of bisphenol fluorene and its structural analogs with the N₀-COF coated capillary.The RSDs of intra-day,inter-day and column-to-column of migration time and peak area of four analytes were2.13-2.99%,1.41-3.02%,1.31-5.83%;3.57-5.24%;3.34-9.24%,6.33-9.14%,respectively.The separation mechanism was studied in the experiment.The results showed that hydrophobic interaction and?-?interaction were the main factors affecting migration order.This method was successfully applied to separate and detect four bisphenols analytes in plastic bottled beverages.Chapter 4:A new OT-CEC method for the separation and determination of bisphenol A and its analogues was established using the prepared N₀-COF coated capillary as separation channels.Under optimal conditions,five bisphenols analytes were successfully achieved baseline separation.The RSDs of the intra-day,inter-day and column-to-column of the five analytes migration time and peak area were0.07-0.41%,1.68-5.50%;1.05-3.20%,1.52-4.17%;1.54-4.45%,4.04-8.96%,respectively.The separation effect of the N₀-COF coated capillary did not decrease significantly after 200 continuous runs.This method has been successfully used to simultaneously separate and detect five bisphenols in plastic bottled beverages.The factors affecting separation behavior were also investigated.The results showed that?-?interaction between the analytes and the coating was the main factor affecting separation behavior.Chapter 5:Conclusions and prospects.