LC-MS Ion Source Alignment for Sensitivity and Vacuum Protection
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Solution Overview
Problem
Liquid chromatography-mass spectrometry devices using micro-electrospray ionization techniques face issues with frequent clogging of small spraying openings, requiring frequent maintenance and adjustments, and contamination of the vacuum chamber, which complicates device durability and maintenance.
Innovation Solution
The alignment of the ion source components, including the spray tip, counter electrode, front stage electrode, subsequent stage electrode, and vacuum chamber introduction electrode along a common axis reduces neutral particle contamination and allows for reproducible positioning and maintenance in an atmospheric environment, enhancing sensitivity and device robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If micro-electrospray ionization is used to reduce sample flow rate for high sensitivity, then sensitivity is improved, but the small opening diameter causes frequent clogging requiring maintenance
Solution Approach 1:
The ion source is divided into two separate chambers: an atmospheric pressure chamber containing the spray tip and ionization region, and a vacuum chamber containing the mass analyzer. This segmentation allows the spray tip to operate at atmospheric pressure with better tolerance to clogging, while the mass analyzer maintains vacuum conditions.
Solution Approach 2:
A skimmer cone is introduced as an intermediary component between the atmospheric pressure chamber and vacuum chamber. It serves as a transition element that allows ions to pass from atmospheric pressure to vacuum while blocking neutral particles and solvent molecules, protecting the vacuum chamber from contamination.
2Measurement precision
If aligned configuration is used to increase ion introduction efficiency, then signal intensity is improved, but neutral molecules and droplets contaminate the inlet and fine aperture
Solution Approach 1:
The ion source is divided into two separate chambers: an atmospheric pressure chamber containing the spray tip and ionization region, and a vacuum chamber containing the mass analyzer. This segmentation allows the spray tip to operate at atmospheric pressure with better tolerance to clogging, while the mass analyzer maintains vacuum conditions.
Solution Approach 2:
A skimmer cone is introduced as an intermediary component between the atmospheric pressure chamber and vacuum chamber. It serves as a transition element that allows ions to pass from atmospheric pressure to vacuum while blocking neutral particles and solvent molecules, protecting the vacuum chamber from contamination.
3Stability of the object's composition
If aligned configuration is used to ensure stability, then ionization stability is improved, but vacuum chamber contamination requires stopping vacuum for maintenance
Solution Approach 1:
The ion source is divided into two separate chambers: an atmospheric pressure chamber containing the spray tip and ionization region, and a vacuum chamber containing the mass analyzer. This segmentation allows the spray tip to operate at atmospheric pressure with better tolerance to clogging, while the mass analyzer maintains vacuum conditions.
Solution Approach 2:
A skimmer cone is introduced as an intermediary component between the atmospheric pressure chamber and vacuum chamber. It serves as a transition element that allows ions to pass from atmospheric pressure to vacuum while blocking neutral particles and solvent molecules, protecting the vacuum chamber from contamination.
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 configuration increases sensitivity, simplifies maintenance, and prevents contamination of the vacuum chamber, enabling efficient and durable operation of the liquid chromatography-mass spectrometry device without the need to stop the vacuum.
Implementation Method 1
an electrospray ion source (ESI) using the electrospray ionization technique. This is an ionization technique for generating ions by spraying a sample solution at atmospheric pressure
Implementation Method 2
there is a method in which heated dry gas such as N2 is blown on the droplets of the sprayed sample solution to facilitate the evaporation of the sample droplets
Data Source
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AI summary
This invention improves the sensitivity of a liquid chromatography-mass spectrometry device by reducing the number of neutral particles that are not ionized during ionization and the number of low-molecular ions from a solvent used in the liquid chromatography. Said liquid chromatography-mass spectrometry device is provided with ion sources (102, 104, 120, 121), a mass spectrometry unit, a detector, and three electrodes (105, 106, 107) laid out so as to be parallel to each other. The first electrode (105) and the second electrode (106) have openings (122, 123) that allow ions to pass therethrough. The trajectories of said ions are deflected between the second electrode (106) and the third electrode (107), thereby directing ions generated by the ion sources (102, 104, 120, 121) towards the mass spectrometry unit.