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Electrofilament deposition and off‐column detection of analytes separated by capillary electrophoresis
Author(s) -
DeVault Gerald L.,
Sepaniak Michael J.
Publication year - 2000
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/(sici)1522-2683(20000401)21:7<1320::aid-elps1320>3.0.co;2-j
Subject(s) - chromatography , analytical chemistry (journal) , capillary action , capillary electrophoresis , capillary electrochromatography , detection limit , analyte , chemistry , electrophoresis , substrate (aquarium) , buffer (optical fiber) , materials science , oceanography , composite material , geology , telecommunications , computer science
Capillary electrophoresis interfaced with electrospray is a convenient technique for continuously transferring column effluent from capillary‐to‐planar format. Conditions are optimized to produce a narrow (˜ 20 μm) liquid filament (electrofilament), which is capable of depositing spatially focused bands with track widths that are routinely 100 μm. A fiber optic‐based, laser‐induced fluorescence cell is employed to monitor the separation on‐column while the separated bands are deposited onto a moving substrate. The photodetection of deposited bands is accomplished by using either a charge‐coupled device camera or a photomultiplier tube. Deterioration of on‐column separation performance is observed when the electrofilament voltage is applied. Elevating the inlet of the capillary column, to provide hydrodynamic flow, restores separation performance. Substrate temperature and translational rates are optimized with respect to both off‐column separation efficiency and signal intensity. Off‐column separation efficiencies of 65 000 plates per meter were achieved. A linear dynamic range of 10 3 and a limit of detection of 10 —8 M were obtained for kiton red deposited onto a reversed phase thin‐layer chromatography plate. To demonstrate the applicability of this technique to more complex separation solutions, a dye mixture was successfully separated and deposited with sodium dodecyl sulfate in the running buffer.