In-column fiber-optic laser-induced fluorescence detection for CE

Area of Science:

• Analytical Chemistry
• Optical Engineering

Background:

• Capillary electrophoresis (CE) requires sensitive detection methods.
• Conventional laser-induced fluorescence (LIF) detectors for CE can suffer from laser scattering.
• Developing compact and efficient detectors is crucial for CE applications.

Purpose of the Study:

• To construct and evaluate a highly sensitive in-column fiber-optic LIF detector for CE.
• To reduce laser scattering effects compared to conventional LIF detection systems.
• To demonstrate the utility of the developed detector for analyzing specific analytes.

Main Methods:

• An in-column fiber-optic probe was integrated into the CE capillary for excitation light delivery.
• A diode-pumped solid-state blue laser (457 nm) served as the excitation source.
• Fluorescence emission was collected via microscopy, filtered, and detected by a photomultiplier tube.

Main Results:

• The developed detector is a simple and compact optical system.
• It effectively reduces laser scattering from the capillary and fiber.
• Demonstrated successful separation and determination of D-penicillamine labeled with naphthalene-2,3-dicarboxaldehyde.
• Achieved a detection limit of 0.8 nM (S/N = 3).

Conclusions:

• The in-column fiber-optic LIF detector provides a sensitive and robust method for CE.
• This detection scheme is attractive for sensitive fluorescence detection in CE applications.
• The system's simplicity and reduced scattering offer advantages over conventional methods.