Study On Technique Of Wide-bore Electrochromatography And New Stationary Phase For Capillary Electrochromatography

Capillary electrochromatography is a new micro-separation technique with high performance and fast speed. Much research is focused on its theory, column technique, new stationary phase and application. The main work of this dissertation is shown as follow:1. Wide bore electrochromatography (WE) techniqueThe separation channel of CEC is restricted to capillary scale with id smaller than 100μm due to the limit of Joule heat, which results in low loadability and poor concentration detectability. In order to solve this problem, a new device was setup to perform wide bore electrochromatography. A quartz tube with millimeter id was used as the separation channel and a proper coolant was pumped through the inner cooling capillary which is coaxially inserted into the separation channel to dispel the Joule heat generated during electrophoresis. The WE system made it possible to perform electrochromatography in a wide bore tube.Polyacrylamide monolithic column was prepared successfully on the WE system.The column was evaluated in the electrochromatography mode using thiourea, naphthalene and biphenyl as probe compounds. Results indicated that this system can dissipate Joule heat in situ in real time, and has higher loadability compared with CEC. Agarose gel column was prepared on the WE system. Higher electric field strength could be applied across the gel column due to the inner cooling mechanism, which made the separation faster than conventional agarose gel electophoresis. At the same time, lower concentration detectablility was obtained due to direct UV detection and longer light distance.2. Sulfated poly (β-cyclodextrin) silica-based monolithic column for CECA sulfated poly (β-cyclodextrin) silica-based monolithic column was prepared in capillary. Then it was evaluated in the CEC mode. Good enantiomeric separations were obtained when the column was applied in chiral separation. 3. Carbosilane dendrimer packed column for CEC Carbosilane dendrimer modified silica was synthesized and then packed into capillary by slurry method to perform CEC. Results indicated that carbosilane dendrimer stationary phase has typical reversed phase characteristics; comparable hydrophobic selectivity was obtained even with low bonding density. Several neutral compounds were separated on the stationary phase with satisfactory efficiency. The theoretical plate number for thiourea was almost up to 90 000 N m-1.