Flow Cell Light Scattering for Stable LC Baselines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing chromatography devices fail to address the issue of refractive index artifacts in liquid chromatography devices caused by rapid changes in solvent concentrations, leading to disturbances in chromatogram baselines.
Innovation Solution
A liquid chromatography device with a detection apparatus that includes a scattering plate to scatter light from a scattering plate between the light source and the photometry flow channel, which is provided between the light source and the photometry flow channel, which is provided between the light source and the flow cell, randomly scattering light to mitigate refractive index artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the inner diameter of the flow cell is enlarged to suppress distortion of the chromatogram baseline, then the baseline stability is improved, but the internal capacity of the flow cell increases
Solution Approach 1:
The flow cell is designed with a non-uniform inner diameter that varies along the flow direction. Specifically, the inner diameter is smaller at the inlet end and larger at the outlet end, creating local variations in flow characteristics. This local quality change allows the flow cell to maintain stable baseline by optimizing light path interaction with the eluent interface while controlling the overall volume increase.
2Stability of the object's composition
If the inner diameter of the flow cell is configured to increase toward the outlet to suppress baseline distortion, then the baseline stability is improved, but the structural complexity of the flow cell increases
Solution Approach 1:
The flow cell employs a gradually varying inner diameter along the flow direction, creating local quality differences that optimize optical path characteristics. This gradual transition from smaller inlet diameter to larger outlet diameter suppresses baseline distortion caused by refractive index effects while maintaining a relatively simple overall structure that can be manufactured using conventional techniques.
3Device complexity
If a narrow flow channel with inner diameter of approximately 1 mm is used, then the device complexity is reduced, but refractive index artifacts cause disturbances in the chromatogram baseline
Solution Approach 1:
The flow cell is designed with a non-uniform inner diameter that varies along the flow direction, creating local quality differences in the flow channel. This variation optimizes the interaction between light and the eluent interface, suppressing refractive index artifacts and baseline disturbances while maintaining a relatively simple overall structure that can be manufactured conventionally.
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 device effectively suppresses disturbances in the chromatogram baseline by randomly scattering light, ensuring accurate measurement of components even when using eluents with differing concentrations.
Implementation Method 1
a scattering plate capable of randomly scattering the light irradiated from the light source, the scattering plate being provided between the light source and the flow channel of the flow cell along a direction of travel of light from the light source, so that in use, the light irradiated from the light source shines on the flow channel of the flow cell in a randomly scattered state
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A liquid chromatography device (A) includes a column (52) that separates components in a specimen sample, an eluent supply mechanism (3) that alternately supplies two or more types of eluent (La,Lb) to the column, and a detection apparatus (53) into which the eluents (La,Lb) are introduced after having passed through the column (52). The detection apparatus (53) detects a specified component of the sample contained in the eluents. The detection apparatus (53) includes a flow cell (70), a light source (71), a light-receiving unit (72,73,74), and a scattering plate (76). The flow cell (70) includes a flow channel (70B) through which the eluents (La,Lb) flow. The light source (71) is provided outside of the flow cell (70) and irradiates light onto the eluents (La,Lb) flowing through the flow channel (70B). The light-receiving unit (72,73,74) is provided outside of the flow cell (70) and receives light that has passed through the flow cell (70). The scattering plate (76) is provided between the light source (71) and the light-receiving unit (72,73,74) along a direction of travel of light from the light source (71).