Capillary Separated Vaporization Chamber for LC-MS
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Solution Overview
Problem
Current electron ionization liquid chromatography mass spectrometry (LC-MS) methods with supersonic molecular beams face issues such as solvent delivery tube clogging, low vaporization efficiency, and poor robustness due to the use of thermally assisted spray, which leads to sample degradation and limited sample throughput.
Innovation Solution
A capillary separated vaporization chamber and nozzle device is introduced, using a capillary transfer line to separate the vaporization chamber from the supersonic nozzle, allowing for electrospray or pneumatic spray formation at above atmospheric pressure, reducing heat load on the solvent delivery tube and enabling easier maintenance, and using helium as a nebulizing gas to improve sample ionization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If thermally assisted spray is used for sample vaporization, then vaporization efficiency is improved, but solvent delivery tube clogging occurs and robustness deteriorates
Solution Approach 1:
The system is divided into two separate chambers: a first chamber for spray formation and a second chamber for sample vaporization. This segmentation allows spray formation to occur at atmospheric pressure while vaporization occurs in a separate controlled environment, preventing clogging in the solvent delivery tube while maintaining efficient vaporization.
Solution Approach 2:
A capillary transfer line acts as an intermediary component connecting the first chamber and second chamber. This capillary enables the transfer of sprayed sample from the atmospheric pressure chamber to the vaporization chamber, separating the spray formation process from the vaporization process and eliminating the clogging issue while preserving vaporization efficiency.
2Productivity
If thermally assisted spray is used, then sample vaporization is enhanced, but sample degradation occurs and sensitivity is reduced
Solution Approach 1:
By separating spray formation and vaporization into different chambers, the system allows spray formation at atmospheric pressure followed by controlled vaporization in the second chamber. This segmentation prevents excessive thermal stress on samples during the spray formation stage, reducing sample degradation while maintaining effective vaporization.
3Ease of repair
If the vaporization chamber is opened for maintenance, then clogged solvent delivery tube can be serviced, but vacuum is lost and productivity decreases
Solution Approach 1:
The solvent delivery tube and spray formation components are extracted from the vacuum chamber and placed in a separate first chamber that operates at atmospheric pressure. This allows the solvent delivery tube to be accessed, inspected, and maintained without breaking the vacuum seal of the mass spectrometer system, thereby maintaining continuous analysis throughput while enabling easy maintenance.
4Ease of operation
If pneumatic assisted nebulization is used, then spray formation is improved, but gas flow reduces vacuum pump throughput and sensitivity is reduced
Solution Approach 1:
The system separates spray formation (requiring pneumatic assistance) from the vacuum environment. The first chamber where pneumatic assisted nebulization occurs operates at atmospheric pressure, allowing adequate gas flow for spray formation without impacting the vacuum pump throughput of the mass spectrometer system in the second chamber.
Solution Approach 2:
The capillary transfer line serves as an intermediary that transfers the sprayed sample from the atmospheric pressure first chamber to the vacuum second chamber. This intermediary connection allows pneumatic assisted nebulization to occur without introducing excess gas flow into the vacuum system, preserving vacuum pump throughput and sensitivity.
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 enhances robustness, sensitivity, and the range of analyzable compounds by reducing clogging, improving vaporization efficiency, and allowing for easier service without venting the vacuum system, while maintaining high ionization efficiency and flexibility in sample analysis.
Implementation Method 1
The capillary transfer line separates the first chamber and the second chamber, maintaining a pressure differential between the atmospheric pressure first chamber and the vacuum second chamber
Implementation Method 2
expanding the vaporized sample and solvent from the supersonic nozzle into a vacuum system, forming a supersonic molecular beam with vibrationally cold molecules
Implementation Method 3
ionizing with electrons the sample compounds while contained as vibrationally cold molecules in the supersonic molecular beam
Data Source
AI summary
There is provided a capillary separated vaporization chamber and nozzle method and device for improved electron ionization liquid chromatography mass spectrometry of samples in a supersonic molecular beam. The device includes a vaporization chamber located upstream of a supersonic nozzle; a capillary separating the vaporization chamber and the supersonic nozzle, means for spray formation from sample in a flowing liquid; a vacuum system into which the supersonic nozzle induces supersonic expansion of the vaporized sample compounds and solvent vapor, for forming a supersonic molecular beam with vibrationally cold sample molecules and vaporized solvent; flythrough electron ionization ion source; mass analyzer; an ion detector and means for data processing of the resulting mass spectral information, for identifying and/or quantifying the chemical content of the sample.