The Preparation Of Pheny Lalanine-substituted Calix[4]Arene Coated Capillary Column And Application In Capillary Electrophoresis

A new phenylalanine-substituted calix[4]arene (PHE-Cx4) coated capillary column (mPHE-Cx4) was successfully prepared using y-aminopropyltriethoxysilane (KH-550) as linking agent and characterized with low and steady EOF and special selectivity. Because of these advantages, it was used as capillary column in electrophoresis analysis of hazardous small ions in food effectively.1. PHE-Cx4stationary phase material which was synthesised in our laboratory was used to prepare the coated capillary column. Then it was characterized by IR, EOF and separation of benzenediol. Compared with bare capillary column, the result indicated that the coated capillary column was prepared successfully, which showed low and steady EOF and special selectivity.2. With mPHE-Cx4and buffer of10mmol/L borax-10%acetonitrile (pH,8.60), two OT-CEC methods were developed and compared for the determination of benzoic acid with positive voltage and negative voltage respectively. In addition, field-amplified sample stacking (FASS) was also investigated and optimized with water plug length of50mabrxlO s and sample injection of-25kV×20s. From the results, the peak time was shorter and the detection limit was lower of the method with negative voltage. Based on these, the FASS preconcentration even can lower the detection limit to0.01u.g/mL and make great contributions to trace analysis.3. Under the optimal conditions, OT-CEC and OT-CEC-FASS of bromate were established with mPHE-Cx4and even applied to analyze the anion in flour and drinking water. The best conditions were list below:the former was50mbar×5s sample injection; the latter was50mbar*8s water plug length and-15kV×16s sample injection. The buffer and separation voltage of the two methods both were5mmol/L phosphate-0.3mmol/L CTAB (pH,7.20) and-15kV. The results told us that the detection limit of OT-CEC-FASS was0.006μg/mL which was about1000times than OT-CEC and can provide a effective method for trace determination of bromate.