Segmented Collision Cell for Fast SRM Mass Spectrometry
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Solution Overview
Problem
Current mass spectrometry techniques face challenges in achieving fast Selected Reaction Monitoring (SRM) on triple quadrupole mass spectrometers, as existing collision cells optimized for sensitivity result in prolonged times for precursor ion selection to product signal observation, exceeding 2 milliseconds, and even axial field configurations do not significantly improve reaction speed, necessitating a design that favors fast reaction pathways without compromising sensitivity.
Innovation Solution
The implementation of a mass spectrometer system with either multiple separate collision cells or a single collision cell with multiple segments, allowing dynamic selection of the appropriate collision cell or segment based on experimental requirements, featuring a 'short' collision cell for rapid fragmentation and a 'long' cell for high-sensitivity detection, with independent control of collision gas pressure and RF voltages to optimize reaction conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a collision cell is optimized for sensitivity with longer path length, then detection sensitivity is improved, but reaction time increases beyond acceptable limits
Solution Approach 1:
The collision cell is divided into multiple segments (first collision cell segment, second collision cell segment, third collision cell segment) with different path lengths. The shorter segments enable fast reaction pathways while the longer segments provide sensitivity for low-abundance fragments, resolving the contradiction between speed and sensitivity.
Solution Approach 2:
The system dynamically selects which collision cell segment to use based on the specific analyte and fragmentation requirements. This dynamic configuration allows optimization of reaction time for each transition while maintaining sensitivity when needed.
2Device complexity
If a single collision cell is used for all SRM transitions, then device complexity is reduced, but the system cannot simultaneously optimize for both fast reactions and high sensitivity
Solution Approach 1:
The collision cell is segmented into multiple sections with different characteristics. This segmentation enables the system to handle multiple SRM transitions efficiently by routing ions through appropriate segments, increasing productivity without excessive complexity.
Solution Approach 2:
The multi-segment collision cell serves multiple functions: fast fragmentation in shorter segments and high-sensitivity detection in longer segments. This multi-functionality allows a single device to handle diverse SRM requirements.
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 enables efficient fragmentation reactions within a short time frame, achieving rapid ion transit and high sensitivity, capable of processing 500 SRM transitions per second, while maintaining the sensitivity required for detecting fragment abundances below threshold limits.
Implementation Method 1
the precursor ions are subjected to fragmentation (e.g. in a collision cell)
Data Source
Figure 1A
Figure 1B~1C
Figure 1D~1E
AI summary
Mass spectrometer systems and methods of operation for detecting a presence of or a quantity of one or more analytes of a sample are disclosed, wherein a compartmented or partitioned ion collision cell having multiple segments or compartments is employed and wherein the mass spectrometer system has the capability of dynamically choosing the appropriate collision cell segment or compartment that is suitable for particular experimental requirements.