Radial Ion Guide Array for Compact High-Resolution Spectrometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ion mobility spectrometers face challenges in achieving high resolution at low pressures, requiring long drift tubes which are impractical for commercial instruments, due to limitations in the E/P parameter and resulting diffusion losses.
Innovation Solution
The design incorporates a multi-section ion guide with radial apertures and transient DC voltages to propel ions through a tortuous path, increasing effective drift distance without lengthening the device, using stacked ring ion guides with aligned radial apertures and DC biases to transfer ions radially between sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a long drift tube is used to achieve high resolution ion mobility separation at low pressure, then resolution is improved, but device size and complexity increase
Solution Approach 1:
The ion guide is divided into multiple sections (first ion guide section, second ion guide section, and transfer section) with different functional characteristics. Each section can have different electrode configurations and voltage applications, allowing the system to achieve long effective drift path through radial transfer while keeping individual sections compact
Solution Approach 2:
The invention transitions from linear axial ion transport to multi-dimensional transport by adding radial transfer between stacked ion guide sections. Ions are transferred radially between sections through aligned apertures, creating a three-dimensional ion path that increases effective drift length without proportionally increasing overall device dimensions
2Adaptability or versatility
If pressure is reduced for mass spectrometer operation, then compatibility with mass spectrometry is improved, but diffusion losses increase and resolution decreases
Solution Approach 1:
The ion guide employs dynamic RF voltages applied to ring electrodes that create time-varying pseudo-potential wells. These dynamic fields actively confine ions radially throughout their passage through the low-pressure device, continuously counteracting diffusion losses that would otherwise occur at reduced pressures
Solution Approach 2:
The system changes the electrical parameters (RF voltage amplitude, frequency, and phase relationships) to optimize ion confinement at different pressures. By adjusting these parameters, the device maintains effective ion guidance and reduces diffusion losses while operating at low pressures compatible with mass spectrometry
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 ion mobility separation resolution and transmission efficiency, allowing for compact, high-resolution ion mobility spectrometers with increased effective drift length, reducing the overall instrument size while maintaining performance.
Implementation Method 1
Opposite phases of an RF voltage are applied to adjacent electrodes so that ions are confined by a pseudo-potential well within the ion tunnel ion guide
Implementation Method 2
The transient DC potentials generate a travelling wave which moves along the axial direction and translates ions along the ion mobility separator
Implementation Method 3
As ions are transmitted through the ion tunnel ion guide, the ions become separated temporally according to their ion mobility
Implementation Method 4
A DC potential bias is arranged to be maintained across the transfer section so that ions are transferred radially from one ion guide section to another
Data Source
AI summary
An ion guide array is disclosed comprising a first ion guide section and a second ion guide section. Each ion guide section may comprise a plurality of electrodes having an aperture through which ions are transmitted in use. A transfer section is arranged at the exit of the first ion guide section and ions are transmitted radially from the first ion guide section into the second ion guide section. Electrodes in the transfer section may have a radial aperture enabling ions to be transmitted radially from the first ion guide section to the second ion guide section.