Fluorescence imaging of light absorption for axial-beam geometry in capillary electrophoresis

Research output: Contribution to journalArticle

Abstract

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.

Details

Authors
  • Jonas Johansson
  • T Johansson
  • S Nilsson
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics
Original languageEnglish
Pages (from-to)2233-2238
JournalElectrophoresis
Volume19
Issue number12
StatePublished - 1998
Peer-reviewedYes