A full-contact fluorescent detection cell for capillary electrophoresis

Abstract

The invention discloses a full-contact fluorescent detection cell for capillary electrophoresis, which includes a detection cell body component, a positioning component and a fixing component. The fluorescence detection cell of the present invention adopts an orthogonal optical path structure, so that the excitation, optical fiber II and liquid optical path are vertically conjugated in pairs; the simple structure is that the liquid flow path and the excitation and receiving optical fibers are in physical contact, and the detection area is still The use of quartz material ensures the continuous operation of electroosmotic flow, and is suitable for capillary electrophoresis-fluorescence detection; in addition, the matching positioning components and fixing components are designed to make the installation and use of the detection pool more convenient.

Description

technical field [0001] The invention relates to a contact type fluorescent detection cell for capillary electrophoresis. Background technique [0002] Fluorescence detection is one of the detection technologies with the highest sensitivity at present, and has high selectivity and response stability; capillary electrophoresis uses capillary as the separation channel, and ions or charged particles are distributed in the capillary according to their mobility or / and High-efficiency and rapid separation technology with different coefficients has the characteristics of high separation efficiency, short analysis time, and small injection volume. Capillary electrophoresis-fluorescence detection, which combines the advantages of the above two technologies, has been widely used in life sciences, bioengineering, environmental protection, food and drug monitoring and other related fields. [0003] In microfluidic analysis systems (including flow injection, microcolumn liquid chromatogr...

AI Technical Summary

Problems solved by technology

But it has the following disadvantages: 1. Before the excitation light reaches the sample, it has to pass through two optical interfaces: air-quartz capillary wall-sample solution; the significant difference in refractive index (RI) (1.0-1.47-1.33), making the light Reflection, refraction and total reflection inside the tube wall occur here, and the cylindrical shape of the capillary exacerbates the optical distortion of the excitation beam, and the reflected excitation light is received by the collection fiber, resulting in higher background signal and noise levels

2. Before the fluorescence reaches the collection fiber, it passes through three optical interfaces: sample solution-quartz capillary wall-air-quartz fiber; the refractive index (RI) is 1.33-1.47-1.0-1.47 in sequence; according to the Fresnel equation, in each optical There will be a corresponding reflection loss at the interface, and its size depends on the two RI values ​​of the optical interface. The greater the difference, the greater the loss; especially from the optically sparse medium (lower refractive index) into the optically dense medium ( When the refractive index is higher), when the angle of the incident light is greater than the critical value, total reflection will occur; in the on-column detection, the propagation of fluorescence has experienced two optically sparse-optical dense interfaces, that is, the sample solution-quartz capillary wall And air-silica fiber, resulting in a large loss of fluorescence intensity, reducing the sensitivity of the detector

Images