Capillary Electrophoresis Detector Using a Light Emitting Diode and Optical Fibres

Abstract

The construction of a simple absorption monitor for capillary electrophoresis, based on a bright blue-green light emitting diode as radiation source, is described. Fibre optic coupling between light source, capillary and photodiode detectors was employed. It was found that, owing to the use of a high intensity light emitting diode, no optical focusing elements were required. The performance of the device was found to be comparable to that of a commercial detector, and the versatility is demonstrated with methods for the determination of transition metal ions by complexation with 4-(2-pyridylazo)resorcinol and the indirect detection of other inorganic cations and anions using organic dyes.

A collinear light-emitting diode-induced fluorescence detector for capillary electrophoresis

“…The combination of extremely high stability, reasonably high intensity, small size, low cost, and very long lifetime makes LED an attractive excitation source for spectroscopic detectors [7,8]. Several groups have made significant contributions to LED-based fluorescence detection used in CE.…”

Design and performance of a light‐emitting diode detector compatible with a commercial capillary electrophoresis instrument

“…Noise levels were lower than with traditional light sources. A baseline noise of 3610 25 AU was observed with a 75 mm capillary filled with water during the application of voltage. Direct detection of metal-Arsenazo I complexes was performed using LEDs as light sources.…”

Numerical Modelling of Light Propagation for Development of Capillary Electrophoretic and Photochemical Detection Systems

“…This can be achieved by installing an aperture or by using an optical fibre to illuminate the capillary and collect the light for detection. Such application of optical fibres has been reported already several years ago [12], [13]. Application of any of these two approaches has an impact on the overall performance of the detection system.…”