Ion Mobility Spectrometer Ion Trap Potential Difference Dynamics
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Solution Overview
Problem
Mass spectrometers face challenges in transferring ions from an ion trap to an ion mobility spectrometer due to significant gas outflow, which can cause fragile ions to fragment when using inappropriate electric fields.
Innovation Solution
A mass spectrometer design where the potential difference between the ion trap exit and the ion mobility spectrometer entrance increases over time, allowing ions to be accelerated into the ion mobility spectrometer without fragmenting, with the potential difference varying from an initial ΔV(t1) to a later ΔV(t2) to accommodate ions of varying mass-to-charge ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a constant potential difference is applied to drive ions from the ion trap into the ion mobility spectrometer, then ions can be transferred against gas outflow, but fragile ions will fragment due to excessive electric field strength
Solution Approach 1:
The patent applies a time-varying potential difference across the ion trap exit region, transitioning from a higher initial potential to a lower final potential during the ion transfer process. This dynamic voltage adjustment allows efficient transfer of ions with different mass-to-charge ratios while preventing fragmentation of fragile ions, resolving the contradiction between transfer efficiency and ion integrity.
Solution Approach 2:
The patent changes the electrical parameter (potential difference) as a function of time during the ion transfer process. By adjusting the voltage from an initial higher value to a lower final value, the system optimizes both ion transfer efficiency and prevents ion fragmentation, simultaneously addressing both contradictory requirements.
2Force
If a high potential difference is used to accelerate ions against significant gas outflow, then ions can be driven into the ion mobility spectrometer, but fragile ions will fragment
Solution Approach 1:
The patent uses a dynamically changing potential difference that starts high to provide sufficient acceleration force against gas outflow, then reduces to prevent ion fragmentation. This time-dependent voltage adjustment resolves the contradiction between needing strong acceleration force and avoiding harmful ion fragmentation.
Solution Approach 2:
The patent employs a time-dependent voltage waveform that varies during the ion transfer period, providing high initial acceleration followed by reduced field strength. This periodic variation in electrical field intensity allows ions to be accelerated against gas flow while preventing fragmentation during the transfer process.
3Quantity of substance
If ions are accumulated in an ion trap at low pressure, then ion storage is efficient, but driving ions against significant gas outflow requires problematic electric fields
Solution Approach 1:
The patent simplifies the electric field control by using a time-varying potential difference applied to the ion trap exit region. This dynamic voltage approach efficiently transfers accumulated ions against gas outflow without requiring complex multi-stage field configurations, resolving the contradiction between ion accumulation efficiency and field control simplicity.
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 transfer of ions with a wide range of masses and mobilities into the ion mobility spectrometer without fragmentation, improving the analysis of a larger mass range in a single separation process.
Implementation Method 1
The potential difference between the exit of the ion trap and the entrance to the ion mobility spectrometer or separator increases with time, and hence ions having a relatively high mass to charge ratio will now be urged or accelerated into the ion mobility spectrometer or separator against an outflow of gas without being fragmented
Implementation Method 2
the ions will then begin to separate temporally according to their mass to charge ratio as they exit the ion trap in the same manner as ions being injected into a drift region
Data Source
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AI summary
An ion mobility spectrometer (2) is disclosed wherein the potential difference between the exit region of an ion trap (1) arranged upstream of the ion mobility spectrometer (2) and the entrance region to the ion mobility spectrometer (2) is varied temporally with time in order to optimise the transmission of ions from the ion trap (1) into the ion mobility spectrometer (2) so as to avoid fragmentation of the ions.