Exceeding 5000-Fold Concentration of Dilute Analytes in Micellar Electrokinetic Chromatography
Joselito P. Quirino,
*
Shigeru Terabe
When a neutral analyte zone is injected into a charged
pseudostationary phase, the length of the zone is predicted to be
narrowed by 1/(1 + k), where k is the retention
factor. The conditions for zone narrowing to occur assume negligible
electroosmotic flow, a relatively constant electric field along the
capillary column, and no pseudostationary phase in the injected analyte
mixture. The theoretically expected concentration enhancement was
demonstrated experimentally. Consequently, the detection sensitivity of
analytes in micellar electrokinetic chromatography (MEKC) can be
improved significantly. For example, 9 to 18 parts per billion of an
environmentally important racemic herbicide spiked in lake water
was separated by MEKC and detected by ultraviolet absorption.
Faculty of Science, Himeji Institute of Technology, Kamigori,
Hyogo, Japan 678-1297.
*
To whom correspondence should be addressed. E-mail:
jquirino{at}sci.himeji-tech.ac.jp
