Comparison of field‐enhanced and pressure‐assisted field‐enhanced sample injection techniques for the analysis of water‐soluble vitamins using CZE |
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Authors: | Qingqing Liu Yaling Liu Yu Guan Li Jia |
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Institution: | Ministry of Education, Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou, China. Fax: +86‐20‐85216052 |
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Abstract: | A new online concentration method, namely pressure‐assisted field‐enhanced sample injection (PA‐FESI), was developed and compared with FESI for the analysis of water‐soluble vitamins by CZE with UV detection. In PA‐FESI, negative voltage and positive pressure were simultaneously applied to initialize PA‐FESI. PA‐FESI uses the hydrodynamic flow generated by the positive pressure to counterbalance the reverse EOF in the capillary column during electrokinetic sample injection, which allowed a longer injection time than usual FESI mode without compromising the separation efficiency. Using the PA‐FESI method, the LODs of the vitamins were at ng/mL level based on the S/N of 3 and the RSDs of migration time and peak area for each vitamin (1 μg/mL) were less than 5.1%. The developed method was applied to the analysis of water‐soluble vitamins in corns. |
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Keywords: | Field‐enhanced sample injection Pressure‐assisted field‐enhanced sample injection (PA‐FESI) Water‐soluble vitamins |
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