用于高效液相色谱的高信噪比、集成式、高可靠的发光二极管诱导荧光检测器的研究

High performance liquid chromatography (HPLC) is a widely applied separation and analysis technology for liquid phase substance. Fluorescence detector (FLD) is a common, high sensitive and selective detector for HPLC. Light-emitting diode (LED) has advantages of long lifetime, high stability of light intensity, low energy cost, high optical efficiency, low cost, small size and non-toxic environmental protection. Using LED as light source is beneficial to miniaturization of FLD, and the life time of LED is longer than Xe lamp, the stability of light intensity of LED is higher than Xe lamp. Therefore, developing HPLC used light-emitting diode-induced fluorescence detector (HPLC-LED-IF) has the vital significance. Based on ray tracing method, this project simulates and optimizes the whole optical path, to provide theoretical and practical guidance to high signal-to-noise ratio (SNR) design of optical path of HPLC-LED-IF; develops detection cell of new structure, to reduce the excitation light to get into fluorescence collecting light path, thus to decrease the background noise; optimizes the shape of flow cell and the internal structure and material of joint, to reduce the peak broadening in big volume flow cell; investigates the seal of flow cell, the material of joint and the heat radiation in submillimeter scale of pin of LED, to increase the stability of HPLC-LED-IF; makes the limit of detection (LOD) of the developed HPLC-LED-IF be close to commercial FLD whose light source is Xe lamp.....

高效液相色谱（HPLC）是一种应用广泛的液相物质分离分析技术。荧光检测器（FLD）是HPLC常用的一种高灵敏度、高选择性的检测器。发光二极管（LED）寿命长、光强稳定性高、功耗低、光效高、成本低、体积小、无毒环保。使用LED作为光源有利于FLD微型化，且LED比氙灯的寿命更长、光强稳定性更高。因此，研制用于HPLC的发光二极管诱导荧光检测器（HPLC-LED-IF）具有重要意义。本项目基于光线追迹法，对全光路进行模拟和优化，为HPLC-LED-IF的高信噪比光路设计提供理论和实践指导；研制新型结构的检测池，减少进入荧光收集光路的激发光，降低背景噪音；优化流通池的形状、接头的内部结构和材料，减小大体积流通池中的峰展宽；研究流通池的密封、接头的材料以及LED引脚的亚毫米尺度散热，提高HPLC-LED-IF的稳定性；使研制的HPLC-LED-IF的检测限接近商品化的氙灯光源FLD。

高效液相色谱（HPLC）是一种应用广泛的液相物质分离分析技术。荧光检测器（FLD）是HPLC常用的一种高灵敏度、高选择性的检测器。发光二极管（LED）寿命长、光强稳定性高、功耗低、光效高、成本低、体积小、无毒环保。使用LED作为光源有利于FLD微型化，且LED比氙灯的寿命更长、光强稳定性更高。因此，研制用于HPLC的发光二极管诱导荧光检测器（HPLC-LED-IF）具有重要意义。本项目针对HPLC系统，设计了高灵敏度的发光二极管诱导荧光检测器（LED-IF）。使用光线追迹法对LED-IF的全光路进行模拟和优化；研究了LED与流通池的耦合方式和荧光收集方式，提高了荧光检测信噪比；优化了流通池的形状、接头的内部结构和材料，减小了峰展宽和峰拖尾；研究了LED引脚的亚毫米尺度散热，提高了HPLC-LED-IF的稳定性。采用流动注射方式评价研制的LED-IF的检测限可低至0.01 ppb FITC，总功耗仅1 W；其灵敏度接近市场上最好的商品化荧光检测器（脉冲氙灯光源、光电倍增管检测、整机功耗150 W）。