Tandem Mass Spectrometer Targeted MS/MS Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tandem mass spectrometers face challenges in performing exhaustive MS/MS analysis with high sensitivity and reproducibility while maintaining a short measurement cycle, leading to a decrease in the number of data points per unit time due to the need for frequent MS/MS analysis across a wide mass-to-charge ratio range.
Innovation Solution
A tandem mass spectrometer with a mass spectrometry controller that selects specific mass-to-charge ratio segments based on acquired mass spectrum data, allowing for targeted MS/MS analysis only in segments with significant ion signals, reducing the number of MS/MS analyses required and increasing data points per unit time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If MS/MS analysis is performed frequently across a wide mass-to-charge ratio range, then identification accuracy is improved, but the number of data points per unit time decreases
Solution Approach 1:
The mass-to-charge ratio range is divided into multiple segments, and MS/MS analysis is performed selectively in specific segments rather than uniformly across the entire range. This segmentation allows the system to focus analysis resources on regions containing precursor ions, thereby maintaining identification accuracy while reducing the total number of analyses required and increasing data points per unit time.
2Measurement precision
If MS/MS analysis is performed exhaustively, then component identification is more accurate, but the measurement cycle length increases
Solution Approach 1:
The system performs a preliminary full-range mass spectrometric analysis to identify the presence and positions of precursor ions before conducting MS/MS analysis. This preliminary action enables the subsequent MS/MS analysis to be targeted only at relevant mass-to-charge ratio segments, significantly reducing the measurement cycle length while maintaining exhaustive identification of all components containing precursor ions.
3Reliability
If the number of MS/MS analyses is increased, then sensitivity and reproducibility are improved, but the measurement time increases
Solution Approach 1:
The system applies different analysis strategies to different mass-to-charge ratio segments based on the local presence of precursor ions. MS/MS analysis is performed with high sensitivity and reproducibility in segments containing precursor ions, while skipping segments without precursor ions. This local quality approach maintains reliable component identification within the measurement time constraints.
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 a more accurate and reliable identification of components by improving the retention time accuracy and peak shape in the extracted ion chromatogram, maintaining high sensitivity and reproducibility without necessitating increased analysis speed.
Implementation Method 1
a first mass-separating section (16) configured to select, as a precursor ion, an ion having a specific mass-to-charge ratio or ions having a specific mass-to-charge-ratio range among ions originating from a sample
Implementation Method 2
an ion-dissociating section (17) configured to dissociate the precursor ion
Implementation Method 3
a second mass-separating section (21, 105) configured to perform a mass spectrometric analysis for various product ions generated by dissociation of the precursor ion
Data Source
AI summary
As soon as a set of data is acquired by a mass spectrometric analysis, an accumulated value of the signal intensity on the mass spectrum is calculated for each m/z segment obtained by dividing the entire m/z range covered by the measurement by a predetermined m/z width. Only the m/z segments with accumulated signal-intensity values equal to or greater than a predetermined threshold are selected as the target for an MS/MS analysis. MS/MS analysis is performed for each selected m/z segment, using ions whose m/z values fall within the m/z segment as precursor ions. A measurement cycle which includes mass spectrometric analysis performed one time and MS/MS analysis performed one or more times is repeated. After that, ions originating from the same component are selected based on the retention time of a peak in an extracted ion chromatogram created for each product ion, and the component is identified.