Premium
Comparison of the use of single capillaries and coupled capillaries based on micellar electrokinetic chromatography (MEKC) and sweeping‐MEKC modes
Author(s) -
Shih ChunMin,
Lin ChengHuang
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.200410189
Subject(s) - micellar electrokinetic chromatography , chromatography , chemistry , electrokinetic phenomena , analytical chemistry (journal) , capillary electrophoresis
The use of single capillaries (25 and 50 μm inner diameter (ID)) and coupled capillaries of different diameters (100–50 and 75–25 μm ID) based on micellar electrokinetic chromatography (MEKC) and sweeping‐MEKC modes is compared and reported. Naphthalene‐2,3‐dicarboxaldehyde (NDA)‐derivatized dopamine was selected as the model compound by examining the fluorescence intensity when a violet (410 ± 7 nm, ˜2 mW) light‐emitting‐diode (LED) was used as the light source. When a single capillary (50 μm ID) was used, the detection limit for NDA‐derivatized dopamine was determined to be 2.0 × 10 −7 M (Signal‐to‐nose ratio S/N = 3) based on the MEKC mode. This was improved to 4.0 × 10 −9 M when the sweeping‐MEKC mode was applied. In addition, this can be further improved to 1.0 × 10 −9 M and 5.6 × 10 −10 M when 100–50 and 75–25 μm ID coupled capillaries are used. The use of the coupled capillary is also helpful for improving the separation efficiency. Based on the sweeping‐MEKC mode, the number of theoretical plates ( N ) for the detected peaks were determined to be 6.3 ± 2.7 × 10 5 by means of a single capillary (50 μm ID). This can be improved to 9.4 ± 3.6 × 10 5 and 9.4 ± 0.9 × 10 6 when the 100–50 and 75–25 μm ID coupled capillaries were applied.