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Head‐column field‐amplified sample stacking in a capillary electrophoresis–flow injection system
Author(s) -
Fan Liuyin,
Cheng Yuqiao,
Li Yuqin,
Chen Hongli,
Chen Xingguo,
Hu Zhide
Publication year - 2005
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200500013
Subject(s) - repeatability , chromatography , capillary electrophoresis , analytical chemistry (journal) , capillary action , electrokinetic phenomena , stacking , chemistry , volumetric flow rate , spark plug , materials science , physics , organic chemistry , quantum mechanics , engineering , composite material , aerospace engineering
A simple, effective, and continuous online concentration method for the sensitive detection of alkaloids applying CE‐flow injection analysis with head‐column field‐amplified sample stacking was developed. A series of samples was continuously introduced into the capillary by electrokinetic means without interrupting the high voltage. A short water plug was introduced by the EOF at the capillary inlet end prior to sample introduction. Under optimum conditions, ˜15‐fold improvement in concentration sensitivity was achieved, giving an LOD of about 0.67 and 0.73 μg/mL for ephedrine (E) and pseudoephedrine (PE), respectively. The separation could be achieved within 4 min and sample throughput rate could reach up to 7/h. The repeatability (defined as RSD) was 3.62, 1.51% with peak area evaluation and 1.30, 2.58% with peak height evaluation for E and PE, respectively. This method has been successfully applied to the analysis of commercial pharmaceutical preparations containing E and PE, and the recoveries were 92.3–102.4%.