Performance of an ultraviolet light-emitting diode-induced fluorescence detector in capillary electrophoresis

Abstract

The performance of a fluorescence detector in capillary electrophoresis (CE) using a light-emitting diode (LED) as excitation source is reported. An ultraviolet LED pulsed at a repetition rate of 500 Hz, combined with a time-discrimination and averaging acquisition system, was used. Limits of detection of 3 and 18 fmoles (at a signal-to-noise ratio equal to 3) were achieved for fluorescamine-derivatized bradykinin and lysine, respectively. This system exhibited a linear response for a concentration range between 54 and 417 microM for derivatized lysine, and between 1.81 and 23.58 microM for derivatized bradykinin. This detection system showed to be very convenient for routine analytical applications.

UV Light-Emitting Diode-Induced Fluorescence Detection Combined with Online Sample Concentration Techniques for Capillary Electrophoresis

“…14 Hillebrand et al reported on the application of a pulsed (500 Hz) UV-LED (370 nm; ∆λ = 12 nm) for the detection of fluorescence-derivatized bradykinin and lysine at the femtomole level. 15 Although the UV-LED (375 nm, 2 mW; NSHU550A) is commercially available, the Nichia Corporation (http://www.nichia.co.jp) reported on the successful development of high-output ultraviolet LEDs of 380 nm (85 mW; Model, SIRIUS) and 365 nm (100 mW; Model, i-LED), respectively. More recently, Dupuis et al reported on an AlGaN/AlGaN quantumwell UV-LED and a ternary AlGaN UV-LED grown on sapphire, with peak emission wavelengths at 341 nm and 302 nm, respectively, with a narrow line width of ∆λ = 10 nm that can be used at room-temperature.…”

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

“…Dasgupta and coworkers [4,8] described the use of LED-FD combined with liquid-core waveguide technique in CE, achieving in 200 amole fluorescein of mass detection limit. Recently, Hillebrand et al [9] reported a LED-FD in CE using a pulsed mode-operating ultraviolet LED. Su and Lin [10] determined riboflavin in urine using a blue LED by CE combined with sample stacking.…”

A compact and highly sensitive light-emitting diode-induced fluorescence detector for capillary flow systems

“…Moreover, LED is commercially available at wavelengths ranging from deep-UV to near-IR regions. LED has been used as alternative light source in fluorescence detections [4][5][6]. Unfortunately, owing to its area source and incoherent characteristic, light emitted by an LED usually has a wide divergence angle.…”