Autosampler Seal Pack with Offset Wash Paths for Low Carryover
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Solution Overview
Problem
Existing liquid chromatography systems face issues with high carryover percentages due to inadequate washing of the sample needle, which contaminates subsequent analyses and affects analytical data quality.
Innovation Solution
A seal pack design with vertically offset wash flow pathways that allow wash solution to flow axially along the exterior surface of the sample needle, ensuring thorough cleaning as the needle moves vertically within the seal pack, eliminating the need for a lower wash frit and using a non-metal bushing to protect the needle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional seal pack design is used, then the structure is simple, but the carryover percentage increases due to sample needle contamination
Solution Approach 1:
The seal pack is divided into multiple functional zones with separate wash flow pathways: a first pathway for washing the sample needle exterior surface and a second pathway for washing the interior. This segmentation allows independent optimization of each washing function, effectively reducing carryover while maintaining structural organization.
Solution Approach 2:
The wash flow pathways are positioned at different vertical offsets, creating a three-dimensional washing architecture. The first wash flow pathway is vertically offset from the second, enabling axial washing of the sample needle exterior surface while the second pathway handles interior washing, thus reducing carryover through multi-dimensional washing coverage.
2Manufacturing precision
If multiple wash flow pathways are added to reduce carryover, then cleaning effectiveness improves, but the device complexity increases
Solution Approach 1:
Multiple wash flow pathways are merged into a single integrated seal pack structure with a common body. The first and second wash flow pathways, along with their respective nozzles, are combined within one seal pack component, achieving effective multi-zone washing while avoiding the complexity of multiple separate devices.
Solution Approach 2:
The seal pack is designed as a multi-functional unit that simultaneously performs sample needle exterior washing, interior washing, and sample well washing through its multiple integrated flow pathways. This universal design consolidates multiple washing functions into a single component, improving washing effectiveness without proportionally increasing device complexity.
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 design achieves a carryover percentage of equal to or less than 0.0025%, significantly improving the cleanliness and reliability of analytical results by effectively removing residual sample from the needle.
Implementation Method 1
a wash solution flows axially along an exterior surface of the sample needle in a vertical direction to wash the sample needle
Data Source
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AI summary
A seal pack of a sample manager of a liquid chromatography system having a plurality of wash flow pathways fluidically connected to a central pathway that accommodates a sample needle, wherein a first wash flow pathway is vertically offset from a second wash flow pathway, such that a wash solution flows axially along an exterior surface of the sample needle in a vertical direction to wash the sample needle when flowing from the first wash flow pathway to the vertically offset second wash flow pathway, is provided. Furthermore, an autosampler and associated methods are also provided.