RF Travelling-Wave Ion Sorting for Low-Loss m/z Separation
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Solution Overview
Problem
Mass filters in mass spectrometers are inefficient as they eliminate all ions except those within a specific mass-to-charge (m/z) range, resulting in the wastage of more than ninety percent of potentially relevant compositional information.
Innovation Solution
The use of RF-DC ion sorting devices that apply a combination of radio-frequency (RF) and direct-current (DC) fields to provide initial coarse separation and temporary storage of ion species without relying on gas flow, allowing for spatial and temporal ion separation and sorting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mass filters are used to isolate specific ion species, then ion isolation precision is improved, but ion loss increases significantly
Solution Approach 1:
The patent applies preliminary action by implementing ion mobility separation upstream from the mass filter. This pre-separation step groups ions by mobility characteristics before mass filtering, so that when the mass filter isolates a specific m/z range, fewer ions are discarded. The pre-organization of ions reduces the waste of potentially relevant compositional information while maintaining the precision of mass filter isolation.
2Loss of substance
If ion mobility spectrometry is used for pre-separation, then ion wastage is reduced, but device complexity increases
Solution Approach 1:
The patent merges ion mobility separation and mass filtering into a unified analytical system where both techniques work in sequence. By combining these two separation mechanisms, the system achieves reduced ion wastage while managing complexity through integrated design. The merged approach allows complementary separation principles to work together, maximizing information recovery without requiring completely separate independent systems.
Solution Approach 2:
The patent applies multi-functionality by designing the ion guide system to perform multiple functions: ion transmission, ion mobility separation, and preparation for mass filtering. This universal ion guide structure handles various ion types and separation requirements, reducing the need for specialized components for each function and thereby managing overall device complexity while achieving reduced ion wastage.
3Measurement precision
If trapped ion mobility spectrometry is used for ion separation, then spatial resolution is improved, but analysis time increases
Solution Approach 1:
The patent applies periodic action through the use of RF (radio frequency) fields to trap and manipulate ions in the ion guide. The RF fields are applied periodically to create oscillating electric fields that trap ions at specific positions, enabling spatial separation by mobility. This periodic trapping mechanism achieves high spatial resolution while maintaining relatively fast analysis times compared to continuous DC field methods, as ions can be rapidly manipulated and released for detection.
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 enables the spatial sorting of ions based on their m/z values, improving the analytical efficiency of mass spectrometry by reducing ion wastage and allowing for more precise manipulation and analysis of ions.
Implementation Method 1
applying a set of radio-frequency (RF) voltage waveforms to a series of electrodes that generate a plurality of pseudopotential wells that exert forces on ions within the ion guide that urge the ions to migrate away from the first end and towards the second end of the ion guide
Implementation Method 2
applying, simultaneously with the application of the set of RF voltage waveforms, a set of direct-current (DC) electrical potentials, either to electrodes of the series or to a set of auxiliary electrodes, that generate forces on the ions within the ion guide that are independent of mass-to-charge ratio (m/z) and that urge the ions to migrate away from the second end and towards the first end of the ion guide
Implementation Method 3
whereby there is caused one or more of m/z-dependent spatial separation, differential migration or filtering of ions within the ion guide
Data Source
AI summary
A method of operating an ion optical component comprising a series of electrodes between first and second ends comprises: applying a set of RF voltage waveforms to electrodes of the series that generate a plurality of moving pseudopotential wells that exert forces on ions within the ion optic that urge the ions to migrate from the first end to the second end of the ion optic; and applying, simultaneously with the application of the set of RF voltage waveforms, a set of DC electrical potentials to electrodes of the series that generate a DC field that exerts a force on the ions within the ion optic that urges the ions to migrate from the second end to the first end, whereby there is caused one or more of spatial separation, differential migration or filtering of ions within the ion optical component in accordance with their respective mass-to-charge (m/z) ratios.