SPME Sampling Interface for Low-Dead-Volume Mass Spectrometry
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Solution Overview
Problem
Current mass spectrometry techniques require extensive and time-consuming sample preparation steps, including sample collection and pre-treatment, which can lead to dilution, error, and reduced throughput, especially when analyzing complex biological or environmental samples using solid-phase microextraction (SPME) devices.
Innovation Solution
A system and method that fluidly couples a desorption solvent from a sampling interface directly to an ion source in a mass spectrometer, optimizing the substrate configuration to increase surface area contact with the desorption solvent, allowing for direct ionization of analytes without the need for additional chromatography steps, thereby simplifying the workflow and automating the analysis process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If extensive sample preparation steps (sampling, separation, concentration, derivatization) are performed prior to MS detection, then the analyte detection capability is improved, but the analysis time and complexity increase significantly, and potential sources of dilution and error are introduced
Solution Approach 1:
The patent combines sampling, sample preparation, and extraction into a single integrated SPME step, eliminating the need for separate sampling and pre-treatment steps. The SPME device performs multiple functions simultaneously: collecting the sample, separating the analyte from the matrix, concentrating the analyte, and preparing it for MS analysis, thereby reducing analysis time while maintaining detection capability
Solution Approach 2:
The SPME device serves multiple functions: it acts as a sampling probe, an extraction medium, a concentration device, and a sample introduction tool for MS. This multi-functional approach eliminates the need for separate equipment and steps for each function, reducing both time and complexity
2Measurement precision
If multiple sample preparation and separation steps are performed, then the analyte purification is improved, but the throughput decreases and potential sources of error increase
Solution Approach 1:
The patent merges purification and concentration into a single SPME extraction step, where the coated fiber selectively adsorbs the analyte from complex matrices while rejecting interferents. This eliminates the need for separate purification steps like solid-phase extraction or liquid-liquid extraction, maintaining purification quality while increasing throughput
Solution Approach 2:
The SPME device extracts only the analyte of interest from the complex sample matrix, leaving behind interfering substances. This selective extraction achieves purification without requiring multiple sequential steps, thereby maintaining high throughput
3Reliability
If additional desorption and purification steps via HPLC are performed prior to MS analysis, then the sample preparation reliability is improved, but the analysis time and complexity increase
Solution Approach 1:
The patent extracts the analyte directly onto the SPME fiber in a single step, eliminating the need for HPLC purification. The SPME coating selectively binds the analyte, providing sufficient purification without requiring chromatographic separation, thereby reducing equipment complexity while maintaining reliability
Solution Approach 2:
The SPME coating acts as an intermediary that selectively binds the analyte from complex matrices. This intermediate extraction step provides sufficient purification and concentration, making subsequent HPLC steps unnecessary and simplifying the overall system
4Measurement precision
If large volumes of liquid are used in the elution step, then the analyte transfer efficiency is improved, but the sample dilution increases and sensitivity decreases
Solution Approach 1:
The patent extracts and concentrates the analyte directly onto the SPME fiber in a small volume, eliminating the need for large-volume elution. The analyte is transferred efficiently from the sample matrix to the fiber coating, maintaining high concentration without requiring dilution with large volumes of solvent
Solution Approach 2:
The patent changes the physical state of the sample from liquid to adsorbed phase on the fiber. This phase change allows concentration of the analyte in a minimal volume on the fiber surface, eliminating the need for large-volume liquid elution and preventing dilution
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 reduces the need for complex sample preparation, increases sensitivity, and enhances throughput by enabling fast and efficient coupling of SPME devices to MS systems, maintaining sensitivity and selectivity while minimizing human error and sample dilution.
Implementation Method 1
a desorption solvent utilized in a sampling interface to desorb one or more analyte species from a substrate
Implementation Method 2
desorb one or more analyte species from a substrate into the desorption solvent
Implementation Method 3
an ion source for ionizing the one or more analyte species desorbed into the desorption solvent
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
Methods and systems for delivering liquid sample to an ion source and subsequent analysis by mass spectrometry. In accordance with various aspects of the present teachings, MS-based systems and methods are provided in which desorption solvent is used in sampling interface to desorb analyte species from an SPME device that is coupled to an ion source to ionize analyte species desorbed into the desorption solvent for MS analysis (e.g., without a liquid chromatography (LC) column between the sampling interface and the ion source). In various aspects of the methods and systems described herein, configuring the sampling interface can be optimized so as to reduce the fluid volume dead space about the fluid inlet so as to concentrate the one or more analyte species desorbed at optimized conditions from the SPME substrate in a decreased volume of the desorption solvent when the SPME device is inserted into sampling interface.