Charge State Selection in Mass Spectrometry
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Solution Overview
Problem
Current capillary electrophoresis-based mass spectrometry and ion mobility spectrometry techniques do not effectively utilize the correlation between electrophoretic mobility, charge state, and mass-to-charge ratio to selectively transmit desired charge states of analyte ions, leading to inefficient ion transmission and potential interference.
Innovation Solution
A method that separates analytes by electrophoretic mobility, ionizes them, and uses a mass filter or filter based on physicochemical properties to vary mass-to-charge ratios or other properties as a function of elution time, allowing only desired charge states to be transmitted, thereby optimizing ion transmission and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional capillary electrophoresis-based mass spectrometry is used to separate and analyze analytes, then analyte separation by electrophoretic mobility is achieved, but ion transmission efficiency is poor and interference from unwanted charge states occurs
Solution Approach 1:
The patent applies preliminary action by establishing a predetermined relationship between elution times, mass-to-charge ratios, and charge states before the actual analysis. This relationship is obtained in advance through calibration or previous experiments, allowing the mass filter to be pre-configured with the expected charge states for different elution times, thereby improving transmission efficiency and reducing interference during the actual measurement process
Solution Approach 2:
The patent utilizes parameter changes by dynamically adjusting the mass-to-charge ratio transmission window of the mass filter based on the elution time of analytes. As different analytes elute at different times with different charge states, the mass filter parameters are changed in real-time to match the expected charge states, optimizing ion transmission and eliminating unwanted charge state interference
2Productivity
If the mass filter transmits all charge states without selection, then ion transmission efficiency is maximized, but spectral complexity and interference increase
Solution Approach 1:
The patent applies local quality by selectively transmitting different charge states at different elution times rather than applying a uniform transmission criterion. The mass filter is configured with time-dependent mass-to-charge ratio windows that match the local charge state characteristics of analytes eluting at specific times, thereby maintaining high transmission efficiency while reducing spectral complexity through targeted charge state selection
3Object-generated harmful factors
If charge state selection is implemented without using the predetermined relationship, then device complexity increases, but without achieving effective charge state filtering
Solution Approach 1:
The patent implements feedback by using the predetermined relationship between elution times, mass-to-charge ratios, and charge states to control the mass filter settings. The system continuously monitors elution time and adjusts the mass filter transmission window based on the predetermined relationship, creating a closed-loop control system that effectively filters charge states without requiring overly complex additional hardware
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 enhances the selective transmission of desired charge states, reduces interference, and improves the accuracy and efficiency of mass spectrometry and ion mobility spectrometry by correlating electrophoretic mobility with gas-phase charge state and mass-to-charge ratio, leading to better data recording and analysis.
Implementation Method 1
Capillary electrophoresis is a known technique which is used to separate ionic species in a conductive medium in the presence of an electric field. Capillary electrophoresis causes ions in solution to migrate with velocities based on their solution charge
Implementation Method 2
ionising the separated analytes as they elute from the separator so as to form analyte ions
Data Source
AI summary
A method of mass spectrometry or ion mobility spectrometry is disclosed in which analyte ions of a desired charge state are isolated. The method comprises: separating analytes according to their electrophoretic mobility; ionising the analytes; and mass filtering the resulting analyte ions, wherein the mass to charge ratios of the ions transmitted by a mass filter are varied as a function of the electrophoretic mobility and according to a predetermined relationship such that substantially only ions having said desired charge state are transmitted by the mass filter.