Unusual peaks and baseline shifts in capillary electrophoresis

J Capillary Electrophor. 1996 May-Jun;3(3):131-7.

Abstract

Emersion peaks, baseline shifts, and spontaneous-marker peaks in CE are documented. These baseline perturbations are observed in a simple CE system that does not employ sample injection and with sodium benzoate as the running electrolyte. Emersion peaks are attributed to the preferential adsorption of electrolyte at the air-solution interface formed upon emersion of the capillary inlet. Baseline shifts are believed to be caused by field-dependent changes in electrolyte concentration entering the capillary. These shifts may be accompanied by spontaneous-marker peaks, which may be caused by diffusion into or out of the capillary inlet between electrophoretic experiments. All baseline perturbations are detected as a change in UV absorbance signal and are transported by electroosmotic flow.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Benzoates
  • Benzoic Acid
  • Calibration
  • Capillary Action
  • Electrolytes
  • Electrophoresis, Capillary / instrumentation*
  • Electrophoresis, Capillary / methods*
  • Reproducibility of Results

Substances

  • Benzoates
  • Electrolytes
  • Benzoic Acid