Sol-Gel Concentrating Device for Capillary Electrophoresis Sensitivity
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Solution Overview
Problem
Capillary zone electrophoresis (CZE) has limited sensitivity due to short in-capillary path lengths, requiring higher analyte concentrations for detection, which can lead to sample manipulation issues and potential loss or contamination, especially when analyzing dilute samples.
Innovation Solution
A sol-gel concentrating device with a channel containing a polymerized alkylsilicate gel matrix and chromatographic sorbent particles is used, formed through a step-wise heating process to create a stable monolith within a capillary tube, enhancing analyte concentration and detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If capillary zone electrophoresis is used for analysis, then fast and efficient sample separation is achieved, but detection sensitivity is limited due to short in-capillary path lengths
Solution Approach 1:
The system is divided into two functional segments: a concentrating device (pre-column) and a separation capillary. The concentrating device accumulates analytes from a large volume sample, then transfers the concentrated analytes to the separation capillary for fast electrophoretic separation. This segmentation allows the detection sensitivity to be improved by concentration while maintaining the fast separation capability.
Solution Approach 2:
The invention adds a spatial dimension to the analysis by incorporating a concentrating device that occupies additional volume outside the narrow capillary. This external concentration chamber provides a larger path length and volume for analyte accumulation, compensating for the limited in-capillary path length and enhancing detection sensitivity without compromising separation speed.
2Measurement precision
If higher analyte concentrations are used for detection, then detection sensitivity improves, but sample manipulation issues and potential loss or contamination occur
Solution Approach 1:
The invention extracts the concentration function from the main capillary electrophoresis system and places it in a separate concentrating device. This extraction allows concentration to be achieved in a controlled environment with minimal sample manipulation, reducing the risk of sample loss or contamination while still achieving the required detection sensitivity.
Solution Approach 2:
The concentrating device acts as an intermediary between sample introduction and capillary electrophoresis separation. It provides a buffer zone where samples can be concentrated under controlled conditions before entering the separation capillary, minimizing direct manipulation of the sample in the narrow capillary and reducing associated risks of loss or contamination.
3Measurement precision
If a sol-gel concentrating device is used to concentrate analytes, then detection sensitivity improves, but the monolith may become destabilized during polymerization
Solution Approach 1:
The polymerization process is initiated and allowed to proceed to a sufficient degree before ethanol evaporation begins. This preliminary polymerization action creates a stable gel network that can withstand the subsequent evaporation process without destabilization, ensuring both monolith integrity and effective analyte concentration.
Solution Approach 2:
The polymerization and evaporation processes are conducted in periodic stages rather than simultaneously. First, polymerization occurs under controlled conditions to establish structural stability, then evaporation proceeds in a subsequent stage. This periodic action sequence prevents monolith destabilization while achieving the desired concentration effect.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sol-gel concentrating device significantly improves the detection sensitivity of CZE by concentrating analytes, allowing for the analysis of low-concentration samples with enhanced peak resolution and reproducibility, even at very low concentrations, without destabilizing the monolith.
Implementation Method 1
a) filling a tube with a composition comprising an alkylsilicate material, ethanol, and particles; b) heating the composition in a step-wise manner at temperatures from 35°C to 60°C to accelerate polymerization of the slurry
Implementation Method 2
heating the composition from b) at a temperature from 60°C to 80 °C to evaporate the ethanol; and c) curing the heated composition from c) at a temperature from 90°C to 130 °C
Implementation Method 3
heating the composition from b) at a temperature from 60°C to 80 °C to evaporate the ethanol
Implementation Method 4
a sol-gel concentrating device comprising a channel that contains a column of a monolith of a polymerized alkylsilicate gel matrix containing chromatographic sorbent particles
Implementation Method 5
Capillary electrophoresis (CE) is a process for separating molecules based on their size or charge. In capillary electrophoresis molecules are introduced into a fluid-filled capillary tube and subjected to an electric field
Data Source
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AI summary
The present invention relates to novel methods and apparatus for improving the sensitivity of capillary zone electrophoresis (CZE). The invention particularly concerns devices comprising a channel that contains an in-line sol-gel column to concentrate samples being subjected to capillary zone electrophoresis, and the use of such devices to enhance the sensitivity of capillary zone electrophoresis.