Ion Transport Device Segmented Pole Rods Kinetic Energy Spread
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In mass spectrometry, large variations in initial kinetic energies of ions compromise measurement performance, particularly in resolution and mass accuracy, due to the kinetic energy spread of ions, which is challenging to manage in all-mass MS/MS experiments where cooling periods limit the analysis rate and affect resolution and accuracy.
Innovation Solution
An ion transport device with segmented pole rods and a controlled voltage pattern is used to capture and transport ions of varying mass-to-charge ratios, maintaining them in potential wells and reducing kinetic energy spread, allowing concurrent transport and separation of ions without dispersing them, thereby improving analysis throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ions are cooled by directing them through a cooling region with neutral gas molecules, then kinetic energy spread is reduced and resolution is improved, but analysis rate decreases and productivity is reduced
Solution Approach 1:
The patent applies preliminary cooling of ions in a cooling region before they enter the transport device. This preliminary action reduces the kinetic energy spread of ions upfront, allowing subsequent fast transport without compromising resolution. The ions are pre-cooled using neutral gas molecules, then rapidly transported through the segmented pole rod device, achieving both high resolution and high analysis rate by separating the cooling and transport functions in time.
2Measurement precision
If a longer cooling period is used to reduce kinetic energy spread, then mass accuracy is improved, but the rate of analysis decreases and time is lost
Solution Approach 1:
The cooling action is performed preliminarily before ion transport, establishing the necessary kinetic energy reduction in advance. This allows the system to achieve adequate mass accuracy through brief cooling, then immediately switch to fast transport mode, minimizing time loss while maintaining measurement precision.
Solution Approach 2:
The system dynamically switches between cooling mode and transport mode. The segmented pole rods enable dynamic control where ions are first cooled in a stationary cooling region, then rapidly accelerated through the moving potential wells of the transport device. This dynamic operation allows optimization of both cooling duration and transport speed independently.
3Productivity
If ions are transported rapidly through the device, then productivity and analysis rate are improved, but kinetic energy spread increases and resolution deteriorates
Solution Approach 1:
The patent resolves this contradiction by performing the cooling action preliminarily before rapid transport. Ions are cooled in a dedicated cooling region to reduce kinetic energy spread, then subsequently transported rapidly through the segmented pole rod device. This sequential arrangement allows both high speed transport and maintained resolution by decoupling the cooling and transport phases in time.
Solution Approach 2:
The transport device is segmented into multiple pole rod sections that can independently control potential wells. This segmentation allows different regions to perform different functions: one region for cooling and another for rapid transport. The segmented structure enables spatial separation of cooling and acceleration zones, allowing ions to be cooled then rapidly transported without mixing these conflicting requirements in a single uniform field.
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 resolution and mass accuracy of mass spectrometry by maintaining ions in focused potential wells, reducing kinetic energy spread, and enabling higher analysis rates without compromising resolution or accuracy.
Implementation Method 1
A repeating voltage pattern is applied to the pole rod pairs to create a repeating pattern of potential wells that move along the ion transport device
Implementation Method 2
A first ion plurality is captured in a potential well and transported along the ion transport device
Implementation Method 3
Each pole rod pair is subjected to a RF voltage and a DC voltage
Implementation Method 4
Cooling of the ions to reduce kinetic energy and kinetic energy spread may be accomplished by directing the ions through a cooling region in which the ions lose energy via collisions with neutral gas molecules
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An ion transport device can include a plurality of pole rod pairs arranged in parallel, and a controller. The controller can be configured to apply voltages in a repeating voltage pattern to the pole rod pairs thereby creating a plurality of potential wells capable of capturing ions, and move the repeating voltage pattern along the pole rod pairs to move captured ions along the ion transport device. The ion transport device can be incorporated into a mass spectrometer.