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Fluorescence imaging of light absorption for axial‐beam geometry in capillary electrophoresis
Author(s) -
Johansson Jonas,
Johansson Thomas,
Nilsson Staffan
Publication year - 1998
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.1150191231
Subject(s) - capillary action , capillary electrophoresis , fluorophore , optics , absorption (acoustics) , fluorescence , detector , materials science , laser induced fluorescence , analytical chemistry (journal) , chemistry , physics , chromatography , composite material
A new method for investigation of axial‐beam absorption detection for improved detection limits in microcolumn separations is reported. The method is based on fluorescence imaging of light absorption along a separation capillary. The probing UV light is introduced at one end of the capillary and shows an exponential fall‐off along the capillary. As the UV light propagates through the sample peaks, an additional loss in intensity will be observed. In order to view the absorption profile along the capillary, a background fluorophore is added to the buffer. A charge‐coupled device (CCD) detector and imaging optics are placed beside the capillary to view the capillary in a direction perpendicular to the capillary. Signal integration is employed for consecutive exposures as well as for neighboring detector pixels in order to increase the signal‐to‐noise ratio. Measurements for stilbene 3 with sulforhodamine B as a background fluorophore are presented. The characteristics of the detection method and potential improvements are discussed.