Preparation of Open Tubular Capillary Electrochromatography Column with Immobilized Vancomycin as Chiral Stationary Phase by Microwave Irradiation

Microwave irradiation was introduced into the preparation of open tubular capillary electro-chromatographic(OT-CEC) column with immobilized vancomycin as chiral stationary phase. To evaluate the electrochromatographic performance by different microwave time, microwave power and microwave temperature, the enantiomeric separation of D,L-tryptophan was investigated. The results verified under the optimized conditions, while microwave time was 45 min, microwave power was 300 W, and microwave temperature was 60 degrees C, enantioselectivity was obtained for the chiral amino acid. The change of electroosmotic flow(EOF) was measured by varying the pH values of the mobile phase. The results indicated that vancomycin immobilized capillary decreased EOF effectively and the predominant source of the decrease is resulted from the silica base material. Baseline separation of four enantiomers could be achieved by the column, respectively. The reproducibilities were also evaluated by D,L-tryptophan.