Time-of-Flight Mass Spectrometer Low-Mass Cut-Off Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional mass spectrometry methods face challenges in achieving high sensitivity in the low mass-to-charge ratio region when the mass range is wide, leading to reduced peak intensity and difficulty in comparing mass spectra across different ranges due to the low-mass cut-off phenomenon.
Innovation Solution
A time-of-flight mass spectrometer design that adjusts the radio-frequency voltage applied to ion transport optical elements during multiple measurements to maintain consistent ion passage efficiency in the low mass-to-charge ratio region, regardless of the mass range, by using a controlling unit to determine optimal voltage settings based on a designated mass range, thereby suppressing the deterioration of sensitivity in the low mass-to-charge ratio region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the mass range is widened to cover a broader mass-to-charge ratio range, then the versatility and coverage of the mass spectrometer is improved, but the peak intensity in the low mass-to-charge ratio region deteriorates due to the low-mass cut-off phenomenon
Solution Approach 1:
The patent applies dynamics by making the radio-frequency voltage adjustable and time-dependent. The controlling unit dynamically changes the radio-frequency voltage applied to ion guides during different time periods based on the designated mass range. When a wide mass range is designated, the system applies different voltage levels at different times to transport ions of different mass-to-charge ratios, thereby preventing the low-mass cut-off phenomenon while maintaining wide mass range coverage capability
Solution Approach 2:
The patent applies parameter changes by modifying the radio-frequency voltage parameter. The controlling unit changes the radio-frequency voltage applied to ion guides based on the designated mass range. By adjusting this voltage parameter over time, the system can transport ions across a wide mass-to-charge ratio range while maintaining sufficient peak intensity in the low mass-to-charge ratio region, resolving the contradiction between wide coverage and measurement precision
2Adaptability or versatility
If multiple measurements are performed with different radio-frequency voltage settings to cover a wide mass range, then the mass range coverage is improved, but the time required for mass spectrometry increases
Solution Approach 1:
The patent applies continuity of useful action by performing multiple measurements with different radio-frequency voltage settings in sequence without interrupting the overall measurement process. The controlling unit automatically transitions between different voltage settings and measurements, ensuring continuous data acquisition across the wide mass range. This automated sequential measurement approach covers the entire mass range while minimizing idle time and operational interruptions
Solution Approach 2:
The patent applies preliminary action by having the controlling unit pre-determine the sequence of radio-frequency voltage settings based on the designated mass range before measurements begin. The system prepares and executes a predetermined measurement sequence that efficiently covers the required mass range, reducing the time needed for real-time decision-making and adjustments during the measurement process
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 enhances the peak intensity in the low mass-to-charge ratio region, ensuring higher similarity in peak patterns across different mass ranges, facilitating comparison and preventing underestimation of compound content, even with wide mass ranges.
Implementation Method 1
an ion guide utilizing an ion focusing effect provided by a radio-frequency electric field is used, so that the ions generated under substantially atmospheric pressure can be efficiently transported to the quadrupole mass filter
Implementation Method 2
In the ion guide utilizing a radio-frequency electric field, the ions travel while oscillating due to the interaction between the electric charge of the ions and the electric field
Implementation Method 3
an orthogonal acceleration unit that accelerates ions in a direction orthogonal to the ion guide axis
Implementation Method 4
a time-of-flight mass spectrometry unit including an ion ejecting unit for ejecting ions generated by the ion source or other ions derived from the generated ions into a flight space
Data Source
AI summary
To acquire a mass spectrum for a wide mass range, a normal analysis execution controlling unit controls components to repeatedly perform measurement while changing setting m/z by a predetermined m/z at a time, and a mass spectrum summarizing processing unit summarizes data pieces each obtained by each time of measurement to generate the mass spectrum. Radio-frequency voltage applied to an ion guide and the like is changed based on the setting m/z. The radio-frequency voltage for the setting m/z is determined using a table in which a relationship between a position on an axis between upper and lower limits of the mass range and the radio-frequency voltage is substantially the same regardless of the mass range.