SPME Desorption System Flow-Insulating Connector
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Solution Overview
Problem
Existing systems for desorbing analytes from solid phase microextraction (SPME) devices using continuous solvent flow often result in broad extraction chronograms due to non-instantaneous desorption and analyte dispersion, leading to inefficient transfer of desorbed analytes to detecting instruments.
Innovation Solution
A system and method that utilize a desorption chamber with a void volume of less than 50 μL and a flow-insulating fluid connector to transfer the desorption solution as a substantially undiluted plug of liquid to a flow injector, minimizing mixing with external fluids and ensuring efficient analyte transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a continuous flow of solvent is used to perform desorption, then the analyte is desorbed and transferred to the detecting instrument, but broad extraction chronograms are generated due to analyte dispersion and non-instantaneous desorption
Solution Approach 1:
The system uses periodic action by switching between desorption mode (continuous solvent flow) and injection mode (pulsed transfer) through a fluid switching mechanism. During desorption, solvent continuously flows to dissolve analytes from the SPME device. Then the system switches to injection mode where a discrete plug of desorption solution is transferred to the detector, creating sharp chronograms while maintaining high throughput through rapid cycling between modes.
Solution Approach 2:
The continuous solvent flow is segmented into discrete plugs using a fluid switching mechanism. Instead of continuous flow directly to the detector, the system divides the desorption process into separate phases: desorption phase where solvent continuously contacts the SPME device, and injection phase where a defined volume of desorption solution is transferred as a discrete plug, eliminating dispersion and creating sharp chronograms.
2Quantity of substance
If a large void volume desorption chamber is used, then more analytes can be desorbed, but analyte concentration decreases due to dilution
Solution Approach 1:
The system changes the volume parameter dynamically by using a large void volume chamber during desorption to maximize analyte recovery, then transferring only a small, defined volume of desorption solution to the detector. The fluid switching mechanism allows the system to utilize the full chamber volume for desorption while injecting a concentrated plug of analyte, thus maintaining both high recovery and high concentration.
3Productivity
If continuous solvent flow is used during transfer, then analytes are continuously transported to the detector, but analyte dispersion occurs reducing detection sensitivity
Solution Approach 1:
The system employs periodic action by alternating between continuous solvent flow during desorption and discrete plug transfer during injection. The fluid switching mechanism enables rapid transition between these modes, maintaining continuous analysis capability while ensuring that each injection contains a concentrated, non-dispersed plug of analyte for high detection sensitivity.
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 the concentration and stability of analytes, reduces dilution, and increases the duty cycle and throughput by maintaining analytes in a concentrated state during transfer, resulting in sharper chronogram bands and more reproducible results.
Implementation Method 1
The desorption chamber and the flow injector are fluidly connected by at least a flow-insulating fluid connector
Implementation Method 2
When an SPME device is placed in the solvent flow, the analyte is desorbed by the solvent
Data Source
AI summary
Disclosed herein is a system for desorbing and detecting an analyte sorbed on a solid phase microextraction (SPME) device. This SPME device The system includes a desorption chamber containing solvent required for desorption of analytes from SPME device; a flow injector in fluid connection with the desorption chamber, the desorption chamber and the flow injector being fluidly connected by at least a flow-insulating fluid connector; a solvent source in fluid connection with the flow injector; and a fluid switch that: in a desorption position, allows the solvent to be sprayed from the flow injector while flow-insulating any desorption solution in the desorption chamber, and in an detecting position, turns off the solvent source while maintaining the fluid connection between the flow injector and the desorption chamber, transferring the desorption solution through the flow-insulating fluid connector to the flow injector as a substantially undiluted plug of liquid. The SPME device can be configured to be various morphologies such as, fibers, blades, thin film membranes and even magnetic particles. When magnetic particles are used an additional holder that contains an embedded magnet which holds a plate with a well to hold said magnetic particles is added to the system.