Ion Trap Mobility Spectrometer Dual-Pulse Ion Ejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ion trap mobility spectrometers face challenges in resolving high-mobility and low-mobility ions due to asymmetric peak traces and poor resolution, caused by ion leakage and incomplete clearing of the ionization chamber, leading to distorted spectral analysis.
Innovation Solution
A system and method that utilize a first electric field pulse with a specific polarity to eject ions from the ionization chamber, followed by a second pulse with opposite polarity to reduce ion tailing and enhance ion injection precision, thereby improving the resolution of high-mobility analytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the strength of the electric field is increased to empty the ionization chamber more rapidly, then the clearing speed improves, but ion leakage through the retainer grid increases
Solution Approach 1:
The patent applies periodic action by using a dual-pulse electric field system. A first pulse with first polarity rapidly clears ions from the ionization chamber, followed by a second pulse with second polarity that prevents ion leakage through the retainer grid. This periodic application of opposite polarity pulses resolves the contradiction by achieving both rapid clearing and leakage prevention.
Solution Approach 2:
The second pulse with opposite polarity serves as a preliminary anti-action to counteract the harmful effect of ion leakage. After the first pulse clears the chamber, the second pulse is applied to create an electric field that opposes ion movement toward the retainer grid, thereby preventing leakage before it can occur.
2Quantity of substance
If the width of the kickout pulse is increased to eject more slow ions, then the ion ejection completeness improves, but the width of detected peaks increases
Solution Approach 1:
The patent uses periodic action with two distinct pulses of different widths and polarities. The first pulse has a width optimized for ejecting slow ions completely, while the second pulse has a narrower width to prevent peak broadening. This sequential application resolves the contradiction between complete ejection and peak resolution.
Solution Approach 2:
The patent changes multiple parameters of the electric field pulses: polarity (first vs. second), width (first width for completeness, second width for resolution), and timing (sequential application). By optimizing these parameters independently for each pulse, the system achieves both complete ion ejection and sharp peak resolution.
3Measurement precision
If the kickout pulse width is reduced to maintain peak resolution, then the spectral resolution improves, but ion tailing increases
Solution Approach 1:
The second pulse with opposite polarity acts as a preliminary anti-action to prevent ion tailing. After the first narrow pulse maintains peak resolution, the second pulse counteracts any ions that would otherwise form tails, thereby eliminating the harmful effect while preserving spectral resolution.
4Productivity
If the electric field strength is increased for rapid chamber clearing, then the clearing efficiency improves, but ion loss through the retainer grid increases
Solution Approach 1:
The patent applies periodic action by alternating between a strong first pulse for efficient clearing and a second pulse with opposite polarity to prevent ion loss. This temporal separation allows high clearing efficiency without permanent ion loss, as the second pulse recovers ions that would otherwise be lost.
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
The approach reduces peak tailing and enhances the resolution of spectral peaks, allowing for more precise detection and analysis of materials by regulating the electric field pulses to minimize ion leakage and improve ion injection precision.
Implementation Method 1
A system and method that utilize a first electric field pulse with a specific polarity to eject ions from the ionization chamber, followed by a second pulse with opposite polarity to reduce ion tailing and enhance ion injection precision
Implementation Method 2
an ionization chamber that produces positive ions, negative ions, and free electrons
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An apparatus for detecting constituents in a sample includes a casing and an ionization chamber defined by the casing. The apparatus also includes an ion collector positioned downstream of the ionization chamber. The apparatus further includes a spectral analysis device coupled to the ion collector. The spectral analysis device is configured to generate a detection spectrum representative of ions collected at the ion collector. The detection spectrum includes an analyte peak portion and a peak tailing portion. The apparatus also includes a control system that is configured to generate a first pulse (210) having a first polarity to initiate a discharge of stored ions from the ionization chamber. The control system is also configured to generate a second pulse (212) substantially immediately after the first pulse. The second pulse has a second polarity opposite the first polarity and is configured to reduce the peak tailing portion.