Quadrupole Device Stability Region Switching
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Solution Overview
Problem
Quadrupole devices face challenges in achieving high ion transmission and trapping efficiency when operated in higher-order stability regions due to low acceptance and divergent fringing fields, with existing solutions like Brubaker lenses and high energy injection either being ineffective or reducing resolution.
Innovation Solution
The method involves switching a quadrupole device between initial and higher-order stability regions, applying digital drive voltages with specific waveforms and phases to maintain ion stability and increase transmission, allowing ions to be introduced in a high acceptance region and then transitioned to a higher-order region for beneficial field characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If quadrupole device is operated in higher-order stability regions, then resolution and peak shape are improved, but ion transmission and trapping efficiency deteriorate due to low acceptance and divergent fringing fields
Solution Approach 1:
The patent applies preliminary action by introducing ions into the quadrupole device while it is operated in the first stability region, where acceptance is high and fringing fields are favorable. Ions are allowed to enter and be captured in the ion trap before the device switches to higher-order stability regions for analysis, ensuring high transmission efficiency is achieved during the critical ion introduction phase.
Solution Approach 2:
The patent implements dynamics by dynamically switching the operating stability region of the quadrupole device between different phases of operation. The device transitions from the first stability region (for ion introduction) to higher-order stability regions (for analysis), optimizing both ion transmission and resolution at different times during the operational cycle.
2Manufacturing precision
If quadrupole device is operated in higher-order stability regions, then peak shape is improved, but trapping efficiency deteriorates due to low acceptance
Solution Approach 1:
The patent applies preliminary action by establishing favorable trapping conditions in the first stability region before ions arrive. The ion trap is configured with high acceptance characteristics in this region, ensuring that ions are efficiently captured upon entry. Only after successful trapping does the device switch to higher-order stability regions for improved peak shape during analysis.
Solution Approach 2:
The patent implements dynamics by dynamically adjusting the stability region operation to match the operational phase. During ion introduction, the first stability region provides high trapping efficiency. During subsequent analysis phases, the device switches to higher-order stability regions that optimize peak shape, achieving both requirements at different times.
3Quantity of substance
If Brubaker lenses are used to improve transmission, then ion transmission is improved in first stability region, but they cannot be used in higher stability regions due to lack of continuous stable path
Solution Approach 1:
The patent applies preliminary action by using Brubaker lenses during the ion introduction phase when the device operates in the first stability region. This ensures high ion transmission during the critical entry phase. The lenses are not required during higher-order stability region operation, as ions are already trapped and the device switches to a different operational mode that does not require continuous stable paths through the lenses.
4Quantity of substance
If high energy injection is used to reduce time in fringing field region, then transmission is improved, but resolution is reduced due to fewer RF cycles
Solution Approach 1:
The patent applies preliminary action by allowing ions to enter the quadrupole device at low energy during the first stability region operation, where fringing fields are favorable and do not cause significant losses. This eliminates the need for high energy injection to overcome fringing field effects. Subsequently, when the device switches to higher-order stability regions, ions have already been trapped and can undergo sufficient RF cycles for high resolution without requiring high energy injection.
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 ion acceptance, trapping efficiency, and transmission into and through the quadrupole device, particularly when operating in higher-order stability regions, while maintaining resolution and reducing fringe field effects.
Implementation Method 1
Quadrupole devices such as quadrupole ion traps, linear ion traps and quadrupole mass filters comprise a set of plural electrodes. In operation, one or more drive voltages are applied to the electrodes of the quadrupole device so that ions having mass to charge ratios within a desired mass to charge ratio range will be retained within the device and/or onwardly transmitted by the device.
Implementation Method 2
The drive voltages are selected such that the quadrupole device is operated in one of one or more so-called 'stability regions', i.e. such that at least some ions will assume a stable trajectory in the quadrupole device.
Data Source
Figure 1A~1B
Figure 2~3A
Figure 3B~4
AI summary
A method of operating a quadrupole device is disclosed that comprises operating the quadrupole device in a first mode of operation, and operating the quadrupole device in a second mode of operation. Operating the quadrupole device in the first mode of operation comprises applying one or more first voltages to the quadrupole device such that the quadrupole device is operated in an initial stability region and such that at least some ions are stable within the quadrupole device. Operating the quadrupole device in the second mode of operation comprises applying one or more second voltages to the quadrupole device such that the quadrupole device is operated in a different stability region and such that at least some of the ions that were stable within the quadrupole device in the first mode of operation are stable within the quadrupole device in the second mode of operation.