Image Charge Signal Processing for Ion Trap Mass Spectrometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ion trap mass spectrometers face challenges in accurately processing image charge/current signals due to non-harmonic waveforms, leading to overlapping peaks in the frequency spectrum, which complicates the determination of mass/charge ratios and relative abundances of trapped ions.
Innovation Solution
A method that identifies candidate fundamental frequencies, derives basis signals using calibration signals, and estimates relative abundances by mapping these signals to the image charge/current signal, effectively handling peaks representing second or higher order harmonics to improve accuracy and resolving power without requiring hardware modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a Fourier transform is applied to the image charge/current signal to obtain frequency spectrum data, then mass/charge ratio information can be obtained, but overlapping harmonic peaks occur making it difficult to distinguish individual ion species
Solution Approach 1:
The patent segments the complex frequency spectrum by identifying and separating individual harmonic series for different ion species. Each ion species' harmonics are treated as a distinct pattern that can be individually analyzed, allowing resolution of overlapping peaks through pattern recognition rather than treating the spectrum as a unified mixed signal
Solution Approach 2:
The patent performs preliminary identification of candidate fundamental frequencies and their corresponding harmonic patterns before final mass/charge ratio determination. By pre-identifying which peaks belong to which harmonic series, the method prepares the data in advance to prevent information loss during the analysis process
2Adaptability or versatility
If the mass range of trapped ions is increased to cover more analytes, then versatility is improved, but harmonic peak overlap increases making analysis more difficult
Solution Approach 1:
The patent develops a universal signal processing method that can handle any mass range of ions through the same harmonic identification and separation algorithm. The method is not limited to specific mass ranges but can be applied universally to different ion species by identifying their characteristic harmonic patterns, thereby achieving multi-functionality across diverse analytical needs
Solution Approach 2:
The patent changes the analysis parameters by shifting from analyzing individual peaks to analyzing harmonic patterns and their relationships. By examining the fundamental frequency relationships and harmonic series structures rather than isolated peak positions, the method simplifies the processing complexity even when covering broad mass ranges
3Device complexity
If conventional Fourier transform methods are used without hardware modifications, then device simplicity is maintained, but resolving power is insufficient to distinguish overlapping peaks
Solution Approach 1:
The patent replaces the need for complex hardware modifications with a computational approach. Instead of adding physical components to improve peak resolution, the invention uses software-based harmonic identification and separation algorithms that process the Fourier transform output to achieve superior resolution without any mechanical or hardware changes
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of processing an image charge/current signal representative of trapped ions undergoing oscillatory motion. The method includes: identifying a plurality of fundamental frequencies potentially present in the image charge/current signal based on an analysis of peaks in a frequency spectrum corresponding to the image charge/current signal in the frequency domain, wherein each candidate fundamental frequency falls in a frequency range of interest; deriving a basis signal for each candidate fundamental frequency using a calibration signal; and estimating relative abundances of ions corresponding to the candidate fundamental frequencies by mapping the basis signals to the image charge/current signal. At least one candidate fundamental frequency is calculated using a frequency associated with a peak that falls outside the frequency range of interest and that has been determined as representing a second or higher order harmonic of the candidate fundamental frequency.