Differential Mobility Spectrometer Ion Control
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Solution Overview
Problem
Existing mass spectrometry systems face challenges in performing ion/ion reactions due to unwanted ion-molecule reactions between ESI sources, which deplete reagent ions and hinder the generation of analyte and reagent ions of opposite polarity.
Innovation Solution
A differential mobility spectrometer with multiple filter electrodes and ion inlets allows for the independent control and selective introduction of analyte and reagent ions of opposite or same polarity, preventing ion-molecule reactions and enabling ion/ion reactions within the DMS device or mass spectrometer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If two ESI sources are used to generate analyte and reagent ions simultaneously, then ion/ion reactions can be performed, but unwanted ion-molecule reactions occur that deplete reagent ions
Solution Approach 1:
The patent divides the ion introduction process into separate temporal or spatial segments. One ESI source introduces analyte ions while the other introduces reagent ions at different times or through separate pathways, preventing their premature interaction in the source region. This segmentation eliminates unwanted ion-molecule reactions while maintaining the ability to perform ion/ion reactions when desired.
Solution Approach 2:
The patent introduces ions from one ESI source into the mass spectrometer and performs preliminary mass analysis or separation before introducing ions from the second source. This preliminary action ensures that analyte and reagent ions do not interact prematurely in the source region, preventing reagent ion depletion while still allowing controlled ion/ion reactions to occur when both ion populations are present in the mass spectrometer.
2Quantity of substance
If two ion sources operate in the same source region, then both analyte and reagent ions can be generated, but solvent vapor interferes with ion generation
Solution Approach 1:
The patent extracts or removes solvent vapor from the source region by introducing ions through separate pathways or at different times. By preventing the coexistence of solvent vapor from both ESI sources in the same region, the harmful effects of solvent vapor on ion generation are eliminated while maintaining the ability to generate both analyte and reagent ions.
3Productivity
If ions of opposite polarity are introduced simultaneously, then ion/ion reactions can occur, but unwanted ion-molecule reactions deplete reagent ions
Solution Approach 1:
The patent employs dynamic control of ion introduction timing and pathways. Ions of opposite polarity are introduced at different times or through different pathways, allowing the system to dynamically switch between preventing unwanted reactions and enabling desired ion/ion reactions. This dynamic approach ensures reagent ion availability while maintaining high ion/ion reaction productivity when needed.
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 configuration enhances the control over ion introduction, prevents solvent vapor depletion, and allows for selective transfer of ions into the mass spectrometer, improving the efficiency of ion/ion reactions and reducing unwanted interactions.
Implementation Method 1
A DMS separates and analyzes ions based on the mobility characteristics of the ions. In a DMS, the ions are separated in a drift gas. However, unlike an IMS, the DMS uses an asymmetric electric field waveform that is applied between two parallel electrodes through which the ions pass
Implementation Method 2
the filter electrodes can generate electric fields for passing selected portions of the sample ions based on the mobility characteristics of the sample ions
Data Source
AI summary
An apparatus and method are provided for analyzing samples of molecules. The apparatus comprises a mass analysis system including a differential mobility spectrometer, which includes at least three filter electrodes defining two ion flow paths where the filter electrodes generate electric fields for passing through selected portions of the sample ions based on the mobility characteristics of the sample ions. The differential mobility spectrometer also includes a voltage source that provides DC and RF voltages to at least one of the filter electrodes to generate the electric field, a first and a second ion inlet that receive sample ions, and an ion outlet that outputs the selected portion of the sample ions. A mass spectrometer receives some or all of the selected portion of the sample ions.