Capillary electrophoresis (CE) has established itself as a powerful and widely utilized technique for routine analytical separations, characterized by short run times and high efficiencies. A major drawback to CE is its low concentration sensitivity. Because total system volume is generally only a few μl, the detector flow cell should have a small volume, which imposes a limit on detection sensitivities. In this study, we report a simple method for creating a region of extended path length for absorbance detection in capillary electrophoresis. Up to a six-fold gain in sensitivity, compared to on-column detection, was accomplished when the sleeve-cell was utilized at the detection point.