DMS Precursor Ion Survey Scan for DIA Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional data-independent acquisition (DIA) workflows in tandem mass spectrometry are inefficient, especially for samples with limited sample volumes, due to their non-specific nature, which results in unnecessary data collection and reduced productivity.
Innovation Solution
Implementing a differential mobility spectrometry (DMS) precursor ion survey scan system that uses a processor to ionize samples, separate precursor ions with compensation voltages, and measure mass-to-charge ratios, producing a two-dimensional mapping to optimize the selection of precursor ions for fragmentation, thereby improving the efficiency of DIA workflows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If traditional DIA workflows are used to collect data for all precursor ions in a mass range, then comprehensiveness of data collection is improved, but efficiency and productivity deteriorate due to non-specific fragmentation and unnecessary data collection
Solution Approach 1:
The patent performs a DMS precursor ion survey scan before the main MS/MS acquisition to identify which precursor ions are actually present in the sample. This preliminary action allows the system to select only relevant precursors for fragmentation, avoiding unnecessary data collection for absent or low-abundance ions while maintaining comprehensiveness for present ions.
Solution Approach 2:
The system uses the two-dimensional mapping data from the DMS survey scan as feedback to dynamically adjust the MS/MS acquisition parameters. The mapping information about precursor ion distribution across CoV and m/z dimensions guides the selection of precursors for fragmentation, creating a feedback loop that optimizes both comprehensiveness and efficiency.
2Productivity
If DMS precursor ion survey scan with two-dimensional mapping is implemented to optimize precursor selection, then efficiency and productivity are improved, but device complexity increases
Solution Approach 1:
The patent utilizes the existing DMS device's capability to perform both ion separation and survey scanning functions. The same DMS apparatus that separates ions based on compensation voltage is used to generate the two-dimensional mapping, eliminating the need for separate specialized equipment and reducing overall system complexity.
Solution Approach 2:
The two-dimensional mapping data structure serves as an intermediary that bridges the DMS survey scan and the MS/MS acquisition. This intermediate data representation simplifies the control logic by providing a clear map of precursor locations, making the complex coordination between DMS separation and MS/MS fragmentation more manageable.
3Loss of information
If non-specific DIA fragmentation is performed for all precursor ions, then comprehensiveness is maintained, but sample volume requirements increase making it unsuitable for limited sample volumes
Solution Approach 1:
The patent extracts only the necessary information from the sample by using the DMS survey scan to identify which precursor ions are actually present. Instead of fragmenting all possible precursors in a mass range, the system extracts and fragments only those precursors that are confirmed to be in the sample, reducing the total ion population that requires analysis and making the method suitable for limited sample volumes.
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 reduces inefficiencies in DIA workflows by selectively filtering ions and optimizing precursor ion selection, enhancing the productivity and comprehensiveness of data collection, especially for samples with limited volumes.
Implementation Method 1
an ion source configured to receive a sample and ionize the sample
Implementation Method 2
a differential mobility spectrometry (DMS) device configured to receive ions from the ion source and to separate precursor ions received from the ion source based on a compensation voltage (CoV)
Implementation Method 3
a mass analyzer configured to receive transmitted precursor ions from the DMS device and measure the mass-to-charge ratio (m/z) intensities of the transmitted precursor ions
Data Source
AI summary
Systems and methods are provided for providing a DMS precursor ion survey scan. An ion source configured to receive a sample is instructed to ionize the sample using a processor. A DMS device configured to receive ions from the ion source is instructed to separate precursor ions received from the ion source and transmit precursor ions using two or more CoVs using the processor. A mass analyzer configured to receive transmitted precursor ions from the DMS device is instructed to measure the m/z intensities of the transmitted precursor ions across an m/z range at each CoV of the two or more CoVs using the processor. The measured m/z intensities of the transmitted precursor ions received from the mass analyzer are stored as a function of m/z value and CoV using the processor. This produces a stored two-dimensional mapping of m/z intensities of the precursor ions of the sample.