Thermo-Optical Absorption Detection in 25-μm-i.d. Capillaries: Capillary Electrophoresis of Dansyl-Amino Acids Mixtures
Thermo-Optical Absorption Detection in 25-μm-i.d. Capillaries: Capillary Electrophoresis of Dansyl-Amino Acids Mixtures
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25 μm 内径毛细管中的热光吸收检测：丹磺酰氨基酸混合物的毛细管电泳
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
D. Bornhop
中科院分区：
文献类型：
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作者：
A. Bruno;A. Paulus;D. Bornhop
一个强度调制的257-nm泵浦激光束被用来诱导折射率的变化作为毛细管电泳在线检测系统采用的毛细管内。毛细管内的这些折射率变化通过解调干涉条纹的周期性横向位移来监测，所述干涉条纹由在633 nm处振荡的探测激光束产生，具有相敏放大器。使用内径为25 μm的毛细管在电泳分离和热光检测中具有双重优势。泵送的热在毛细管壁处被有效地淬灭，并且可以沿着分离管施加高电场。这两种效应的组合导致泵浦源的高效分离和快速调制。这通过在不到两分钟内分离三种丹磺酰化氨基酸的测试混合物来证明。仅将350-pg量的总样品注入到柱上，并且检测体积小于10 pL。
An intensity-modulated 257-nm pump laser beam is used to induce refractive index changes inside of a capillary tube employed as an on-line detection system for capillary electrophoresis. These refractive index changes inside the capillary are monitored by demodulating the periodic lateral shifts of the interference fringes, generated by a probe laser beam oscillating at 633 nm, with a phase-sensitive amplifier. The use of capillaries with an internal diameter of 25 μm results in a twofold benefit in electrophoretic separations in conjunction with thermo-optical detection. The pumped heat is efficiently quenched at the capillary wall, and high electrical fields can be applied along the separation tube. The combination of both effects leads to highly efficient separations and fast modulations of the pump source. This is demonstrated by the separation of a test mixture of three dansylated amino acids in less than two minutes. Only 350-pg amounts of total sample are injected onto the column, and the detection volume is less than 10 pL.