Mass Spectrometer Ion Storage Reduces Ion Loss
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Solution Overview
Problem
Conventional quadrupole and triple quadrupole mass spectrometers experience ion loss when modifying the RF and DC voltages applied to the quadrupole mass filters, as ions passing through the analyzer may not reach the detector or have their mass-to-charge ratios altered, leading to discarded detector output signals.
Innovation Solution
A mass spectrometer design that maintains constant mass-to-charge ratios for ions passing through the mass analyzer by using an ion storage portion to store and expel ions as pulsed ions, allowing for modification of ion species during non-entry times and reducing ion loss through precise timing and voltage control, along with an A/D converter for signal processing to enhance detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ions are continuously transported to the detector while voltages are being modified, then the mass spectrometer can maintain continuous operation, but ion loss occurs because ions cannot reach the detector or their mass-to-charge ratios cannot be identified
Solution Approach 1:
The ion storage portion stores ions in advance before voltage modification occurs. This preliminary storage action allows the system to prepare ions for detection before the mass analyzer parameters are changed, preventing ion loss during the transition period.
Solution Approach 2:
The system uses periodic pulsed ion expulsion from the storage portion, synchronized with voltage modification cycles. Ions are stored during voltage changes and then expelled in pulses when stable detection can occur, creating a periodic rhythm that avoids ion loss while maintaining continuous operation.
2Adaptability or versatility
If the mass-to-charge ratio is changed during ion passage through the mass analyzer, then the mass spectrometer can adapt to different ion species, but the detector output signal is discarded because mass-to-charge ratios cannot be identified
Solution Approach 1:
The system pre-stores ions before mass-to-charge ratio changes occur. This allows the mass analyzer to modify its parameters without affecting ions already in the storage portion, ensuring that when ions are expelled for detection, the mass-to-charge ratio is stable and identifiable.
Solution Approach 2:
The ion storage portion acts as an intermediary buffer between the ion source and the mass analyzer. It decouples the ion generation process from the mass analysis process, allowing independent optimization of both functions without causing signal loss.
3Loss of substance
If ions are stored and then expelled as pulsed ions, then ion loss is reduced during voltage modifications, but the device complexity increases due to timing control requirements
Solution Approach 1:
The ion storage portion automatically manages ion storage and expulsion timing based on internal conditions, reducing the need for complex external timing control systems. The system self-regulates the pulsed expulsion rhythm to maintain optimal operation.
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 significantly reduces ion loss during voltage modifications, improves detection sensitivity by preventing unwanted noise, and allows for accurate comparison of ion intensities by maintaining consistent storage and expelling times, resulting in more reliable mass spectrometry data.
Implementation Method 1
ions are stored by the ion storage portion and all stored ions are expelled as pulsed ions
Implementation Method 2
applying an RF voltage and a DC voltage to ahyperbolic quadrupole mass filter (QMF) and passing only the ions of the desired mass-to-charge ratios
Implementation Method 3
detecting the intensities of ions of desired mass-to-charge ratios
Data Source
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AI summary
A spectrometer is offered which can reduce ion loss compared with the prior art even when ions selected by the mass analyzer are modified. The spectrometer includes an ion source (10) for ionizing a sample, an ion storage portion (20) for repeatedly performing a storing operation for storing ions created by the ion source (10) and an expelling operation for expelling the stored ions as pulsed ions, the mass analyzer (30) for passing pulsed ions expelled from the ion storage portion (20) and selecting desired ions according to their mass-to-charge ratio, a detector (60) for detecting pulsed ions passed through the mass analyzer (30) and outputting an analog signal responsive to the intensity of the detection, and a controller (90) for maintaining constant the mass-to-charge ratio of the desired ions selected by the mass analyzer (30) while pulsed ions including the desired ions are passing through the mass analyzer (30).