GCB Membrane for SPE/SALDI-MS Pesticide Analysis
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Solution Overview
Problem
Current MALDI techniques face challenges in analyzing small molecules due to interference from matrix ions and clusters, which are not effectively managed, especially in high molecular weight analytes, and there is a need for improved methods to handle large sample volumes and varying flow rates in pesticide detection.
Innovation Solution
The use of a graphitized carbon black (GCB) membrane in a membrane format for sample preparation, combined with SALDI/MS and LC/MS/MS analysis, allows for efficient retention and desorption of pesticides, reducing interference and enabling analysis of small molecules and large sample volumes with varying flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional MALDI techniques are used with organic acid matrices, then high molecular weight analytes can be analyzed, but matrix ions and clusters interfere with small molecule analysis
Solution Approach 1:
The harmful matrix ions are removed from the system by replacing organic acid matrices with graphitized carbon black particles as the desorption agent. This extraction of the problematic component eliminates ion interference while retaining the beneficial desorption function.
Solution Approach 2:
The chemical composition and physical properties of the desorption agent are fundamentally changed from organic acids to graphitized carbon black. This parameter change transforms the interaction mechanism with analytes, enabling selective desorption without co-ionization of the matrix.
2Loss of substance
If graphitized carbon black membrane is used for SPE, then solvent usage is reduced, but membrane retention capacity must be optimized for large sample volumes
Solution Approach 1:
The GCB membrane serves multiple functions simultaneously: it acts as both the SPE adsorbent medium and the SALDI desorption target. This multi-functionality eliminates the need for separate cartridges and reduces solvent requirements while maintaining capacity for large sample volumes.
Solution Approach 2:
The membrane utilizes the porous structure of GCB particles to provide high surface area for analyte retention during SPE, while the same porous structure allows efficient laser penetration and analyte desorption during SALDI analysis.
3Productivity
If high flow rates are used for large sample volumes, then productivity increases, but retention efficiency may decrease
Solution Approach 1:
The system dynamically adapts to varying flow rates through the inherent properties of the GCB membrane, which maintains retention efficiency across a wide range of flow rates due to its high surface area and optimized particle structure.
Solution Approach 2:
The membrane's physical parameters (surface area, porosity, particle size distribution) are optimized to maintain effective retention even at high flow rates, allowing productivity improvement without sacrificing retention efficiency.
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 significantly reduces analyte loss and solvent usage, maintains high recovery rates, and achieves low detection limits, facilitating effective screening and quantification of pesticides in complex matrices like agricultural water samples.
Implementation Method 1
The graphitized carbon black (GCB) membrane in a membrane format for sample preparation, combined with SALDI/MS and LC/MS/MS analysis, allows for efficient retention and desorption of pesticides
Implementation Method 2
MALDI works based on desorption/ionization of analytes using laser irradiation. The pulsed laser is focused on a sample spot causing desorption and ionization of the sample
Implementation Method 3
Matrices are usually organic acids with non-localized electrons that can absorb the laser energy and transfer it to the analyte of interest
Implementation Method 4
All SALDI mass spectra were obtained using a Voyager DE-STR time of flight mass spectrometer. A pulsed 337 nm nitrogen laser was used for desorption
Data Source
AI summary
A membrane comprising graphitized carbon black (GCB) with dual function for solid- phase extraction and surface -assisted laser desorption mass spectrometry (SPE/SALDI-MS) analysis is disclosed. Devices comprising such membrane and methods utilising such membranes are also disclosed.