毛细管阵列电泳检测过程中的杂散光分析

建立了激光诱导荧光检测系统.采用光学仿真方法,建立与实际光学系统相同的模型.模拟表明:聚焦光束扫描毛细管阵列,轴上光束入射到毛细管内径中心时产生的杂散光最大,在两边逐渐减小.由毛细管产生的杂散光的平均光强是无毛细管时的2.725倍,说明由它产生的杂散光比较严重.对不同大小的内径产生的杂散光影响进行了分析比较,增大毛细管的内径,杂散光增大,但毛细管内径减小会使进样量少,检测困难,同时还会加大清洗与灌胶的难度.综合考虑,选取内径为50 μm的毛细管较为合适.利用自行设计的激光诱导荧光检测系统扫描毛细管阵列,进行了杂散光检测实验,光电倍增管记录所收集到的信号,作出了激光束扫描毛细管的不同位置时的杂散光信号强度分布图,实验与模拟结果相一致.

Analysis of Stray Light in Capillary Array Electrophoresis with Laser Induced Fluorescence Detection

The laser induced fluorescence detection (LIFD) system was built. The same model as the detection system was simulated in emulation software of optics. The stray light is the strongest when the laser illuminates the inner diameter (ID) center of the capillary and it is gradually decreased along two edges. The stray light caused by capillary is 2.725 times larger than the case without capillary. The capillaries of different inner diameters were compared in simulation. The ID of capillary is larger, the stray light is stronger. It is difficult to inject the sample, gel and clean when decrease the ID of capillary. Integrating various factors, the 50 μm ID of the capillary is appropriate. The Scanning the capillary was experimented with LIFD designed by ourselves;the stray light signals received by photomultiplier tube(PMT) are recorded. The stray light distribution figure is obtained. The experiment result is in agreement with the simulation.