Ion Guide AC Oscillation for Adduct Declustering
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Solution Overview
Problem
Existing mass spectrometry techniques fail to effectively remove adduct species from analyte ions, which affect the analysis due to differing physicochemical properties, particularly when using electrospray ion sources.
Innovation Solution
An ion guide with varying RF and AC voltages is used to oscillate clusters of analyte ions and adduct species, allowing controlled detachment of adducts by adjusting amplitude and frequency of AC voltage, and varying transit speed through the guide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If RF voltage is applied to radially confine ions in the ion guide, then ion confinement is improved, but declustering capability deteriorates
Solution Approach 1:
The patent segments the voltage application into two distinct components: RF voltage for radial confinement and separate AC voltages for declustering. This allows independent optimization of each function without interference, resolving the contradiction between maintaining stable ion confinement and achieving effective declustering
Solution Approach 2:
The patent dynamically applies AC voltages with varying amplitudes and frequencies to the ion guide electrodes during ion transmission. This dynamic modulation enables the system to maintain RF confinement while superimposing oscillatory motion that facilitates declustering, allowing both functions to coexist
2Object-generated harmful factors
If AC voltage amplitude and frequency are increased to enhance declustering, then adduct removal is improved, but analyte ion loss increases
Solution Approach 1:
The patent systematically varies AC voltage parameters (amplitude, frequency, phase) to optimize declustering efficiency while minimizing analyte loss. By adjusting these parameters, the system can tailor the oscillatory motion to match the characteristics of different adduct species, achieving selective removal without excessive analyte ion loss
Solution Approach 2:
The patent employs periodic AC voltage application with specific frequencies that resonate with the adduct-analyte cluster dynamics. This periodic action enhances declustering through cumulative effect while controlling the duration and intensity to prevent analyte ion loss
3Productivity
If clusters are moved quickly through the ion guide, then transmission efficiency is improved, but declustering time decreases
Solution Approach 1:
The patent applies AC voltages to induce oscillatory motion and facilitate declustering before the clusters complete their transit through the ion guide. By initiating declustering action early in the transmission process, the system achieves effective adduct removal while maintaining high transmission speed, resolving the contradiction between transmission efficiency and declustering duration
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 method effectively decouples radial confinement and declustering, enabling optimized removal of adducts while preserving analyte integrity, facilitating precise mass and mobility analysis.
Implementation Method 1
applying an RF voltage to electrodes of the ion guide for radially confining ions therein
Implementation Method 2
applying, in a first mode, one or more AC voltage to the ion guide so as to oscillate the clusters such that they collide with molecules of the background gas
Implementation Method 3
oscillate the clusters such that they collide with molecules of the background gas and cause adduct species in the clusters to detach from the analyte ions
Data Source
AI summary
A method of mass and/or ion mobility spectrometry comprising: providing an ion guide comprising a plurality of electrodes and having a background gas therein; applying an RF voltage to electrodes of the ion guide for radially confining ions therein; transmitting clusters of analyte ions and adduct species into the ion guide; applying, in a first mode, one or more AC voltage to the ion guide so as to oscillate the clusters such that they collide with molecules of the background gas and cause adduct species in the clusters to detach from the analyte ions, wherein the one or more AC voltage has a different amplitude and/or frequency to that of said RF voltage; and (i) varying the speed with which the clusters are urged along the ion guide during the first mode; and/or (ii) varying the amplitude and/or frequency of the one or more AC voltage as the clusters travel along the ion guide.