Ion Trap Spectroscopy for Background-Free Isobaric Ion Detection
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Solution Overview
Problem
Current ion spectroscopy methods, such as laser-induced reaction and laser-induced inhibition of complex growth, are limited by the requirement for endothermic chemical reactions and low temperatures, restricting the detection of molecular ions and being non-background-free.
Innovation Solution
A method involving capturing ions in an ion trap, thermalizing them with a buffer gas, and exciting them with electromagnetic radiation to increase kinetic energy, allowing ions to escape the trap and be detected without chemical conversion, enabling background-free spectrum detection of any ion species, including molecular ions, at various temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If laser-induced reaction method is used to detect ion spectra, then mass change of molecular ions can be detected, but only molecular ions with endothermic chemical reactions can be investigated and reaction partners must not condense under cold conditions
Solution Approach 1:
The invention changes the detection parameter from mass change (chemical conversion) to kinetic energy change (physical excitation). By detecting kinetic energy changes through ion ejection from the trap rather than mass spectrometry of reaction products, the method becomes applicable to all ion species regardless of whether they undergo endothermic reactions or condense at cold temperatures.
Solution Approach 2:
The invention replaces the chemical reaction-based detection mechanism with a physical excitation and ejection mechanism. Instead of relying on chemical conversions that change ion mass, the method uses electromagnetic radiation to excite ions, causing kinetic energy changes that result in ion ejection from the trap, which is then detected.
2Measurement precision
If laser-induced inhibition of complex growth method is used, then action spectroscopy can be performed, but very cold temperatures of around 4 K are required and the process is not background-free
Solution Approach 1:
The invention changes the temperature parameter from cryogenic (4 K) to much higher temperatures. By using kinetic energy ejection detection instead of complex growth inhibition, the method no longer requires very cold temperatures, making it applicable to a broader range of experimental conditions and ion species.
Solution Approach 2:
The invention converts the potential background interference present in LIICG methods into a beneficial feature. By detecting ion ejection events rather than attempting to measure subtle changes in complex formation rates, the method achieves background-free spectra because unexcited ions simply remain in the trap and do not contribute to the signal.
3Measurement precision
If chemical reaction partners are used in ion spectroscopy, then mass change detection is possible, but the method is restricted to ions with suitable endothermic reactions and requires reaction partners that do not condense
Solution Approach 1:
The invention extracts and removes the reaction partner component from the spectroscopy method. By detecting kinetic energy changes of the ion itself through ejection from the trap, rather than detecting mass changes through reaction with external partners, the method eliminates the need for carefully selected reaction partners that must not condense at cold temperatures.
Solution Approach 2:
The invention introduces electromagnetic radiation as an intermediary that directly interacts with the ion's internal energy states. This mediator causes kinetic energy changes without requiring chemical reaction partners, simplifying the experimental setup and expanding applicability to all ion species.
4Measurement precision
If action spectroscopy methods are used, then spectral information can be obtained, but background signals are present and chemical conversion is required
Solution Approach 1:
The invention turns the potential background problem into a benefit by using a detection method that is inherently background-free. By detecting ion ejection events caused by kinetic energy changes, the method achieves clean spectra because only excited ions that gain sufficient kinetic energy to escape the trap contribute to the signal, while unexcited ions remain trapped and do not create background noise.
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 method allows for sensitive, universal detection of ion spectra without chemical conversion, suitable for small ion quantities and various types of spectra, including rotational, vibrational, and electronic spectra, without the need for low temperatures, and enables demixing and determining mixing ratios of isobaric ions.
Implementation Method 1
b) thermalizing the ions captured in the ion trap by a buffer gas
Implementation Method 2
c) exciting the thermalized ions in the ion trap by electromagnetic radiation such that a kinetic energy of the ion species in the ion trap changes
Data Source
AI summary
A method for detecting a spectrum of an ion species comprises the steps of a) capturing a subset of ions comprising the ion species in an ion trap; b) thermalizing the ions captured in the ion trap by a buffer gas; c) exciting the thermalized ions in the ion trap by electromagnetic radiation such that a kinetic energy of the ion species in the ion trap changes; and d) detecting the ions leaving the ion trap and/or detecting the ions remaining in the ion trap via a detector. In addition, the disclosure relates to a method for demixing a mixture of two or more ion species with equal mass-to-charge ratio and a method for determining a mixing ratio of a mixture of two or more ion species with equal mass-to-charge ratio. The disclosure further relates to a device for carrying out the above methods.