On-line concentration of chiral cationic molecules in NACE by supercharging electrokinetic stacking

• 作 者: XingguoChen[1]WeifengWang[2]
• 机 构: National Key Laboratory of Applied Organic Chemistry,Lanzhou University,Lanzhou 730000,China
• 出 处: 第八届全国微全分析系统学术会议、第三届全国微纳尺度生物分离分析学术会议暨第五届国际微化学与微系统学术会议
• 发表日期: 2013年期

　　Capillary electrophoresis as a useful method has been wildly used because of its good separation,small injection amount and multiplied detector[1,2].However,the small injection amount makes the lower sensitivity owing to the absorbance-based measurements.Over the past decade,some on-line concentration methods have been developed to enhance the sensitivity [3-5].In this report,a facile on-line concentration method of trace levels chiral cationic molecules (propranolol,PL) in NACE was investigated.The method was based on the electrokinetic injection technology.When injection voltage is applied,the continuous introduction of low pH* sample causes the apparent bulk flow inside the capillary gradually slows down.The EOF of the system was decreased rapidly and close to zero.The cationic analytes could be injected continuously in a long time.The effect of key factors on the proposed method was investigated.Under the optimized condition,21025 and 21040 folds enrichment (10 KV,240 s) in peak areas upon normal CZE(0.5 psi,3 s) method were obtained for R-PL and S-PL,respectively.The developed method provides a prospect for separation and determination of trace chiral drugs by NACE.