Pulsed multi-wavelength excitation using fiber-in-capillary light emitting diode induced fluorescence detection in capillary electrophoresis

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• 作者：Feng Huo ; Hongyan Yuan ; Xiupei Yang ; Michael C. Breadmore ; Dan Xiao
• 关键词：Multi-wavelength ; Pulsed LED ; Gradient index (GRIN) lens ; Collimation ; Fluorescence detection ; Capillary electrophoresis
• 刊名：Talanta
• 出版年：2010
• 出版时间：15 December 2010
• 年：2010
• 卷：83
• 期：2
• 页码：521-526
• 全文大小：496 K

文摘

A novel instrument was developed using a multi-wavelength pulsed LED array with in-column optic-fiber induced fluorescence detection by capillary electrophoresis. The light from 2 different wavelength LEDs (450 nm and 480 nm) was pulsed for short intervals at high intensity. The beam from each LED was collimated and reshaped with the gradient index (GRIN) lens group to achieve a highly effective coupling between LED light source and an optical fiber. The optical fiber was placed inside the capillary for in-capillary LED-induced fluorescence detection. The advantages of this system were validated by the simultaneous determination of vitamin B2 and fluorescein. Detection limits for vitamin B2 and fluorescein were estimated to be 5 nM and 0.29 nM (S/N = 3), respectively. The relative standard deviations (RSDs, n = 6) of the both compounds for migration time and peak area were better than 0.83 % , 2.20 % and 1.21 % , 2.75 % , respectively. The method was applied to the determination of vitamin B2 in commercial tablets and fluorescein in fluorescein sodium injection and the recoveries obtained were in the range of 96.6–102.0 % and 99.9–102.8 % , respectively. It was also applied to human serum, where the recoveries were found to be in the range of 94.4–97.0 % and 92.6–96.4 % , respectively. The system has been successfully applied in separation and determination of the both biological samples with acceptable analytical performance.