Ion Guide Collisional Activation With RF Ion Confinement
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Solution Overview
Problem
Current ion guides in mass spectrometers face challenges in achieving reproducible ion activation with minimal complexity and cost, while maintaining high ion transmission and controlling ion trajectory, due to limitations in existing designs that often result in ion loss and contamination.
Innovation Solution
A method and ion guide design that incorporates a first section with a DC potential gradient applied at a non-zero angle to direct ions into a second section, where an RF field confines the ions, allowing for selective ion activation and neutral separation within a single device, reducing spatial footprint and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a stacked ring ion guide with progressively decreasing aperture is used, then ion transmission efficiency is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The ion guide is divided into multiple stacked ring electrodes with progressively decreasing apertures, where each ring segment performs ion guiding and filtering. This segmentation allows efficient ion transmission while maintaining manageable device complexity through modular construction
Solution Approach 2:
The aperture diameter of the stacked rings is progressively changed (decreased) along the ion path, creating a funnel effect that guides ions efficiently while removing neutral particles and clusters, thereby improving transmission without requiring overly complex mechanisms
2Object-generated harmful factors
If ion activation is performed in the ion guide, then unwanted adducts and clusters are removed, but ion loss increases
Solution Approach 1:
Ion activation is performed locally in specific regions of the ion guide where controlled collision with residual gas occurs, while other regions maintain conditions for efficient ion transmission. This localized approach removes unwanted adducts and clusters without causing excessive ion loss in the entire system
Solution Approach 2:
The residual gas in the ion guide, which could be considered harmful by causing ion collisions and potential loss, is converted into a beneficial medium for activating ions and removing unwanted adducts and clusters through controlled collisional processes
3Reliability
If multiple differential pumping stages are used, then vacuum quality is improved, but spatial footprint and device complexity increase
Solution Approach 1:
Multiple differential pumping stages and ion guiding functions are merged into a single integrated ion guide structure with stacked rings, reducing the overall spatial footprint while maintaining effective vacuum quality through combined ion transmission and neutral particle removal mechanisms
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 efficient ion-neutral separation, ion collection, and ion activation with minimal complexity and cost, while maintaining high ion transmission and precise control over ion trajectory, reducing contamination and ion loss.
Implementation Method 1
applying a DC potential gradient in the first section along a dimension that is at a non-zero angle to the longitudinal axis to direct the ions towards the second section and to cause ion activation
Implementation Method 2
Adjacent electrodes are driven by an RF waveform with opposite sign to confine ions radially and prevent their loss to the electrodes
Data Source
AI summary
A method for ion activation in an ion guide that comprises a first section and a second section, the second section having a longitudinal axis, the method comprising steps of: receiving ions into the first section of the ion guide at a trajectory that is offset from the longitudinal axis; applying a DC potential gradient in the first section along a dimension that is at a non-zero angle to the longitudinal axis to direct the ions towards the second section and to cause ion activation; and applying an RF field in the second section of the ion guide to confine the ions to the ion guide.