Chromatography Injection Unit with Dual Mobile Phase Dilution
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Solution Overview
Problem
Conventional chromatography systems face challenges in balancing mobile phase composition and solvent strength, leading to sample smearing and reduced resolution, especially during large volume injections and multi-dimensional chromatography, where the sample solvent can disrupt the mobile phase, resulting in decreased resolution and increased loading times.
Innovation Solution
The system employs two pump systems to provide a first and second mobile phase component, allowing for precise control of solvent ratios and dilution, enabling independent adjustment of solvent proportions before and after sample injection, thereby optimizing chromatography speed and resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the sample is injected into the full combined mobile phase, then the sample loading capacity is increased, but the sample solvent causes partitioning effects that favor residence in the mobile phase, resulting in sample smearing and loss of resolution
Solution Approach 1:
The mobile phase is segmented into multiple components (first mobile phase component and second mobile phase component) that are mixed in different proportions before and after sample injection. This segmentation allows independent control of solvent strength during the injection phase versus the separation phase, enabling high sample loading without compromising resolution.
Solution Approach 2:
The composition ratio of mobile phase components is dynamically changed: a first ratio is used during sample injection to accommodate high sample loading, then a second ratio is applied afterward to optimize separation and resolution. This parameter change resolves the contradiction between loading capacity and resolution.
2Productivity
If the mobile phase composition is balanced to compromise between speed and quality, then acceptable chromatography operation is achieved, but the sample's own solvent adds to partitioning effects, causing sample smearing and broad signals
Solution Approach 1:
The mobile phase composition is made dynamic rather than static. The system transitions from a first mobile phase composition during sample injection to a second mobile phase composition during separation. This dynamic adjustment allows the system to optimize for both speed during injection and resolution during separation, eliminating the need for compromise.
3Quantity of substance
If large volume injections are performed in preparative chromatography, then the sample loading capacity is increased, but the sample solvent effects are more pronounced, causing increased sample smearing and reduced resolution
Solution Approach 1:
The second mobile phase component acts as an intermediary that modulates the effects of the sample solvent. By adjusting the ratio of the second component, the system can counterbalance the partitioning effects introduced by large volumes of sample solvent, thereby maintaining resolution even when loading capacity is increased.
4Ease of operation
If the sample solvent has greater solvent strength than the mobile phase strong solvent, then the sample can be dissolved for injection, but the sample solvent disrupts the mobile phase, resulting in decreased resolution and increased loading times
Solution Approach 1:
The system applies preliminary anti-action by using the second mobile phase component to counterbalance the strong solvent effects of the sample solvent before the sample actually enters the separation column. This preemptive measure prevents the sample solvent from disrupting the mobile phase and causing resolution loss.
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
This approach enhances sample loading capacity and resolution by allowing for precise control of solvent ratios and dilution, compensating for changes in solvent strength and reducing sample smearing, thereby improving chromatographic separation efficiency.
Implementation Method 1
The first pump system is configured to provide the first mobile phase component, a first portion of the first mobile phase component flowing through a first branch, and a second portion of the first mobile phase component flowing through a second branch
Implementation Method 2
The second pump system is configured to provide the second mobile phase component, a first portion of the second mobile phase component flowing through a third branch, and a second portion of the second mobile phase component flowing through a fourth branch
Implementation Method 3
The injection unit is configured to receive a combined stream, including the first portion of the first mobile phase component provided via the first branch and the first portion of the second mobile phase component provided via the third branch, and to inject the sample into the combined stream to form a sample-containing stream
Implementation Method 4
The sample-containing stream is subsequently combined with the second portion of the first mobile phase component provided via the second branch and the second portion of the second mobile phase component provided via the fourth branch to form a diluted sample-containing stream
Implementation Method 5
The separated compounds may then be directed to a detector for detection and analysis, where each of the compounds emerges from the chromatographic column at a different time corresponding to the respective differential retention of that compound within the chromatographic column
Implementation Method 6
The chromatographic column which may retain the compounds from the sample. The compounds from the sample experience a differential retention with the column's stationary phase, e.g., using packing material or sorbent within the chromatographic column
Data Source
AI summary
An apparatus introduces a sample into a separation unit of a chromatography system with a mobile phase, including first and second mobile phase components. The apparatus includes first and second pump systems, and an injection unit. The first pump system provides the first mobile phase component, first and second portions of the first mobile phase component flowing through first and second branches, respectively. The second pump system provides the second mobile phase component, a first portion of the second mobile phase component flowing through a third branch. The injection unit receives a combined stream of the first portions of the first and second mobile phase components provided via the first and third branches, respectively, and injects the sample into the combined stream to form a sample-containing stream, which is subsequently combined with the second portion of the first mobile phase component to form a diluted sample-containing stream.