Johansson J, Johansson T, Nilsson S
Division of Atomic Physics, Lund Institute of Technology, Sweden.
Electrophoresis. 1998 Sep;19(12):2233-8. doi: 10.1002/elps.1150191231.
A new method for investigation of axial-beam absorption detection for improved detection limits in microcolumn separations is reported. The method is based on fluorescence imaging of light absorption along a separation capillary. The probing UV light is introduced at one end of the capillary and shows an exponential fall-off along the capillary. As the UV light propagates through the sample peaks, an additional loss in intensity will be observed. In order to view the absorption profile along the capillary, a background fluorophore is added to the buffer. A charge-coupled device (CCD) detector and imaging optics are placed beside the capillary to view the capillary in a direction perpendicular to the capillary. Signal integration is employed for consecutive exposures as well as for neighboring detector pixels in order to increase the signal-to-noise ratio. Measurements for stilbene 3 with sulforhodamine B as a background fluorophore are presented. The characteristics of the detection method and potential improvements are discussed.
报道了一种用于微柱分离中提高检测限的轴向光束吸收检测研究的新方法。该方法基于沿分离毛细管的光吸收荧光成像。探测紫外光从毛细管一端引入，并沿毛细管呈指数衰减。当紫外光穿过样品峰时，会观察到强度的额外损失。为了观察沿毛细管的吸收轮廓，向缓冲液中添加了背景荧光团。电荷耦合器件（CCD）探测器和成像光学器件放置在毛细管旁边，以便在垂直于毛细管的方向上观察毛细管。为了提高信噪比，对连续曝光以及相邻探测器像素采用信号积分。给出了以磺基罗丹明B作为背景荧光团对芪3的测量结果。讨论了该检测方法的特点和潜在改进。
