Ion Mobility Fragmentation Patterns for Polymer Connectivity Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for characterizing polymeric molecules using mass and/or ion mobility spectrometry struggle to effectively determine sequence and connectivity information, particularly for molecules with identical subunits but different connectivity, tacticity, and branching.
Innovation Solution
A method involving the separation of analyte ions based on a physico-chemical property, followed by fragmentation or reaction to produce product ions, which are then re-separated according to the same property, allowing for the identification and characterization of the original ions through pattern recognition of the product ions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If standard ion mobility-mass spectrometry approaches are used to characterise polymeric molecules, then mass and mobility information can be obtained, but sequence and connectivity information cannot be effectively determined
Solution Approach 1:
The polymeric molecule is fragmented into smaller subunits through ion mobility separation and mass spectrometry analysis. The separation process divides the complex mixture into individual ion components that can be independently analyzed, allowing sequence and connectivity information to be extracted from the fragmentation patterns of the separated ions.
Solution Approach 2:
The invention adds ion mobility separation as an additional dimension to the traditional mass spectrometry analysis. By separating ions based on their mobility through a drift tube before mass analysis, the method creates a two-dimensional separation space (mobility + mass) that provides enhanced structural information about polymeric molecules, enabling determination of sequence and connectivity that cannot be obtained by mass spectrometry alone.
2Measurement precision
If pre- or post-ion mobility fragmentation is used, then mass and mobility of precursor and fragment ions can be characterised, but molecules with identical subunits and different connectivity cannot be distinguished
Solution Approach 1:
The method uses iterative fragmentation and re-separation cycles where fragment ions are subjected to additional ion mobility separation and further fragmentation. Each cycle provides feedback about the structural characteristics of the ions, allowing the system to progressively resolve connectivity information. The repeated separation and analysis of fragment ions at different stages enables distinction between isomers with identical mass but different connectivity.
3Productivity
If a single separation step is performed, then analysis time is reduced, but unique fragmentation patterns characteristic of specific ions cannot be generated
Solution Approach 1:
The first ion mobility separation step acts as a preliminary action that pre-sorts the ion mixture before fragmentation occurs. By separating ions based on their mobility characteristics prior to fragmentation, the method ensures that subsequent fragmentation patterns can be uniquely traced back to specific parent ions. This preliminary separation prevents signal overlap and enables clear assignment of fragmentation patterns to individual ion species.
Solution Approach 2:
The invention introduces a second ion mobility separation dimension after fragmentation, creating a two-stage separation process. This additional separation step in the mobility domain allows the system to resolve co-eluting fragment ions and assign them to their parent ions based on mobility matching. The dual separation approach (before and after fragmentation) provides redundant information that confirms unique fragmentation patterns without significantly increasing total analysis time.
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 provides an improved method for identifying and characterizing ions, particularly for polymeric molecules, by generating unique fragmentation patterns that are characteristic of the specific ions, enabling better determination of sequence and connectivity information.
Implementation Method 1
analyte ions are separated according to their ion mobility or according to their rate of change of ion mobility with electric field strength
Data Source
Figure 1~3
Figure 4A~4B
Figure 4C~4D
AI summary
A method of identifying and/or characterising ions comprises separating analyte ions according to a first physico-chemical property (ion-mobility), selecting first ions of the analyte ions, and activating, fragmenting or reacting the first ions to produce first product ions, separating the first product ions according to the first physico- chemical property, and determining a pattern of the first product ions. The first ions are identified and/or characterised using the pattern of the first product ions.