Electronic Mass Selector Grid for Ion Filtering
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Solution Overview
Problem
Current ion selection methods in mass spectrometry, such as magnetic sector and quadrupole mass analyzers, face limitations in resolving heavier ions and require complex magnetic fields, whereas time-of-flight mass spectrometers lack efficient mechanisms for selective ion filtering.
Innovation Solution
An electronic mass selector grid is used to selectively pass a subset of ions by varying the applied voltage, allowing for precise ion selection and filtering within a time-of-flight mass spectrometer, enabling the separation and detection of specific ions or threat molecules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic sector mass analyzers are used to separate ions, then ion separation by mass is achieved, but the device complexity increases due to requiring large magnets and curved trajectories
Solution Approach 1:
The patent replaces the mechanical magnetic field system with an electronic field system. Instead of using large magnets to create magnetic fields for ion separation, the invention uses electronically controlled electric fields generated by programmable voltage sources applied to electrode structures. This substitution maintains ion separation capability while significantly reducing device complexity and removing the need for bulky magnetic components.
Solution Approach 2:
The patent changes the fundamental parameter used for ion separation from magnetic field strength to electric field voltage. By using programmable voltage sources that can dynamically adjust electric field parameters, the system achieves mass resolution through temporal and spatial control of electric fields rather than through complex magnetic field configurations, thereby simplifying the overall device architecture.
2Measurement precision
If quadrupole mass analyzers are used to filter ions, then specific mass selection is achieved, but the ability to resolve heavier ions is limited
Solution Approach 1:
The patent implements dynamic control of electric fields through programmable voltage sources that can rapidly change field parameters during operation. This dynamic capability allows the system to adapt to different mass ranges and ion types, enabling both precise mass selection and extended mass range coverage. The electronic field can be reconfigured in real-time to optimize performance for different analytical requirements, unlike fixed quadrupole structures.
Solution Approach 2:
The electronic field-based mass analyzer is designed to perform multiple functions: it can selectively filter ions by mass, resolve ions across a broad mass range, and potentially perform multiple analyses sequentially without physical reconfiguration. The programmable nature of the electric field system provides universal applicability across different mass analysis scenarios, replacing the specialized function of quadrupole filters.
3Adaptability or versatility
If time-of-flight mass spectrometers are used to detect ions, then heavier ions can be detected, but efficient selective ion filtering is lacking
Solution Approach 1:
The patent applies preliminary action by implementing ion filtering through electronically controlled electric fields before ions reach the detector. The programmable voltage sources create time-dependent electric field patterns that pre-select ions based on their mass-to-charge ratio during their flight path, enabling precise mass selection prior to detection. This preliminary filtering enhances the precision of ion selection while maintaining the broad mass detection capability of time-of-flight geometry.
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 method enhances the ability to resolve and select ions by mass, improving the detection of heavier ions and allowing for the identification of specific molecules in mixed gas streams, with flexible operation for both positive and negative ions.
Implementation Method 1
The quadrupole mass analyzer applies an oscillating electric field to an ion beam, allowing only ions of a specific charge-to-mass ratio to pass in a straight line
Implementation Method 2
accelerating the group of ions through a flight region towards an electronic mass selector grid
Implementation Method 3
The time-of-flight mass spectrometer generates a cloud of ions and accelerates the ions into spatially identical flight paths in a field-free drift region, wherein each ion's time of flight is dependent on the charge-to-mass ratio of the ion
Data Source
AI summary
A method of selecting ions includes generating a group of ions, accelerating the group of ions through a flight region towards an electronic mass selector grid, and selectively varying a voltage applied to the electronic mass selector grid, such that only a selected subset of the group of ions passes through the grid. An apparatus for selecting ions includes an ion generator, an ion accelerator for accelerating ions into a flight region, and an electronic mass selector grid responsive to an applied voltage to pass a subset of the ions from the flight region. An apparatus for detecting a threat molecule includes an ion generator for generating ions from a mixed gas stream, an ion accelerator for accelerating the ions into a flight region, and an electronic mass selector grid. The grid passes only a subset of the ions, such as ions and/or ionized fragments of the threat molecule.