Staggered MRM Mass Spectrometry for Mass Axis Drift Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mass spectrometry systems face instability due to mass axis drifts caused by temperature, humidity, and contamination, leading to decreased sensitivity and selectivity in LC-MS methods, which existing strategies to maintain sensitivity compromise selectivity.
Innovation Solution
Implement staggered-multiple reaction monitoring (S-MRM) using a mass spectrometry device with three channel groups measuring at theoretical and shifted m/z values, comparing quantifier/qualifier ratios with a reference, and rejecting transitions outside a predefined tolerance range to maintain sensitivity and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If MS resolution is decreased to sustain sensitivity against mass axis instability, then sensitivity is improved, but selectivity deteriorates due to compromised ability to distinguish signal from sample matrix components
Solution Approach 1:
The patent segments the MRM measurement process into multiple channel groups (at least three), each measuring transitions at different m/z values (theoretical and shifted). This segmentation allows the system to distribute measurements across multiple channels, where at least one channel remains accurate despite mass axis drift, thereby maintaining both sensitivity and selectivity without requiring reduced resolution.
2Productivity
If mass axis calibration is performed less frequently to reduce maintenance time, then productivity is improved, but measurement precision deteriorates due to accumulated mass axis drift
Solution Approach 1:
The patent implements preliminary action by incorporating mass axis drift compensation into the regular MRM measurement process itself. Through continuous monitoring using multiple channel groups with shifted m/z values, the system proactively detects and corrects mass axis drift in real-time, eliminating the need for frequent separate calibration interventions and maintaining high mass accuracy throughout extended operation periods.
3Measurement precision
If environmental conditions (temperature, humidity) are strictly controlled to prevent mass axis drift, then measurement precision is improved, but device complexity and operational cost increase
Solution Approach 1:
The patent implements feedback by continuously monitoring mass axis position through multiple MRM channel groups measuring at different m/z values. The system compares measured transitions against expected theoretical values, detects drift automatically, and compensates by selecting appropriate channels or adjusting measurements. This closed-loop feedback mechanism maintains high mass accuracy without requiring complex environmental control infrastructure.
Data Source
AI summary
A method for multiple reaction monitoring using a mass spectrometry device (106) is proposed. The method comprises the following steps: i) (128) measuring, by using the mass spectrometry device (106), multiple reaction monitoring transitions of quantifier and qualifier of both an internal standard and an analyte using staggered-multiple reaction monitoring, wherein the staggered-multiple reaction monitoring comprises at least three multiple reaction monitoring channel groups, wherein one of the multiple reaction monitoring channel groups measure at respective theoretical m/z values of the quantifier and qualifier of both the internal standard and the analyte and the two other multiple reaction monitoring channel groups measure at respective m/z values shifted to higher and lower values by a predefined level; ii) (130) comparing, for at least two groups, at least two of the quantifier/qualifier ratios of the multiple reaction monitoring transitions of the internal standard with a reference value from a database (126) by using at least one processing device (120), wherein the comparison comprises determining a deviation between the quantifier/qualifier ratios and the reference value; iii) (132) determining from the analyte and the internal standard measured multiple reaction monitoring transitions a measurement result by using the processing device (120), if the deviation for at least one of the quantifier/qualifier ratios is within at least one predefined tolerance range, otherwise rejecting (136) the measured multiple reaction monitoring transitions.