Adjustable Gradient Delay Volume in HPLC Systems
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Solution Overview
Problem
In liquid chromatography, particularly high-performance liquid chromatography (HPLC), the gradient delay volume (GDV) varies across different systems, causing issues with separation reproducibility and detector signal variability, especially with UV detectors at low wavelengths, making it difficult to transfer methods between systems and requiring costly manual mixer replacement or cumbersome automation.
Innovation Solution
A method and system for automatically adjusting the GDV in a chromatography system using a volume adjustment device, allowing for continuous or discrete setting of the mixing volume between 0 μL to 1000 μL, utilizing existing components like the metering device to maintain constant flow and pressure, ensuring application-specific requirements are met without replacing components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the gradient delay volume is increased to improve mixing efficiency and reduce mixture irregularity, then the mixing performance improves, but the analysis time and washing-out time increase unnecessarily
Solution Approach 1:
The patent applies dynamics by making the gradient delay volume adjustable rather than fixed. The volume adjustment device allows the GDV to be dynamically changed between different values (e.g., 0 μL to 1000 μL) depending on the specific application requirements, enabling optimization of both mixing efficiency and analysis time for different detector types and separation conditions
Solution Approach 2:
The patent changes the physical parameter of the gradient delay volume from a fixed value to an adjustable parameter. By providing a volume adjustment device that can set the GDV to different values, the system can optimize mixing efficiency when needed while minimizing analysis time when using detectors insensitive to mixture irregularities
2Manufacturing precision
If manual mixer replacement is performed to adapt to different GDV requirements, then the separation reproducibility improves, but the device complexity and cost increase
Solution Approach 1:
The patent applies universality by designing a volume adjustment device that can be integrated into existing HPLC systems regardless of the original mixer design. This single adjustable component replaces the need for multiple specialized mixers with different fixed volumes, making the system universally adaptable to different GDV requirements while maintaining separation reproducibility
Solution Approach 2:
Instead of replacing physical components (mixers) to change GDV, the patent changes the operational parameter of the existing system by providing an adjustable volume mechanism. This allows the same mixer to effectively provide different GDV values, reducing device complexity while maintaining separation reproducibility
3Stability of the object's composition
If the gradient delay volume is increased to smooth out composition fluctuations, then the mixture irregularity decreases, but the detector signal variability increases due to delayed gradient onset
Solution Approach 1:
The patent applies dynamics by enabling real-time adjustment of the gradient delay volume to match the specific separation method requirements. The volume adjustment device allows the system to dynamically optimize the balance between composition stability and retention time precision for each analytical method, rather than being constrained by a fixed GDV
Solution Approach 2:
The patent changes the GDV parameter from fixed to adjustable, allowing precise optimization for each application. By providing continuous or discrete adjustment options, the system can set the optimal GDV value that simultaneously achieves adequate mixing (composition stability) and minimal retention time shift (retention time precision)
Data Source
AI summary
The invention relates to a method for setting a gradient delay volume GDV of a liquid chromatography system for a chromatography run in liquid chromatography, in particular a high-performance liquid chromatography system, in which a desired value GDVtarget of a gradient delay volume of the liquid chromatography system is ascertained or predefined and, if the value GDVtarget deviates from a specific fixed value GDVactual of a liquid chromatography system, this value GDVtarget is set in a range 0≤ΔGDV=GDVtarget−GDVactual≤Vmax of a volume of a volume adjustment device 5. Furthermore, the invention relates to an automatic sampler for carrying out such a method.