Mass Spectrometer Inlet Reducing Average Flow
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Solution Overview
Problem
Existing mass spectrometry systems face challenges in efficiently transferring ions from atmospheric pressure to lower pressure regions for analysis, leading to increased fluid flow and pressure in the analysis chamber, which requires larger and more powerful pumps, making portable and handheld systems less feasible.
Innovation Solution
A mass spectrometer inlet system with a first conduit for ion transfer and a second conduit for diverting a portion of the ion flow, regulated by a valve and pump, allowing intermittent ion introduction to reduce fluid flow into the analysis chamber, thereby reducing the pressure maintenance workload and enabling smaller, lower-power pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If continuous ion transfer from atmospheric pressure to mass spectrometer chamber is maintained, then ion analysis efficiency is improved, but fluid flow and pressure in the analysis chamber increase, requiring larger and more powerful pumps
Solution Approach 1:
The system implements periodic action by using a valve to intermittently allow ion transfer from the atmospheric pressure region to the mass spectrometer chamber. Instead of continuous transfer, the valve opens and closes in a periodic manner, allowing ions to pass through at specific intervals while blocking the bulk fluid flow. This periodic gating mechanism maintains ion analysis efficiency by ensuring ions reach the chamber regularly, while simultaneously reducing the average fluid flow and pressure buildup in the analysis chamber.
Solution Approach 2:
The valve acts as an intermediary component between the atmospheric pressure ion source and the vacuum mass spectrometer chamber. It mediates the transfer process by selectively allowing ion passage while blocking neutral gas molecules. The valve serves as a gatekeeper that decouples the ion transfer function from the bulk fluid flow, enabling efficient ion introduction without proportionally increasing the fluid load on the pumping system.
2Reliability
If larger and more powerful pumps are used to maintain reduced pressure in the mass spectrometer chamber, then pressure stability is improved, but system size, power consumption, and complexity increase
Solution Approach 1:
By implementing periodic ion transfer through the valve mechanism, the system reduces the average fluid load on the pump. This allows the use of smaller, lower-power pumps that can maintain the required vacuum pressure stability without being oversized. The periodic gating of ion flow prevents continuous high-rate fluid ingress that would demand large pump capacity.
Solution Approach 2:
The system changes the temporal parameter of ion transfer from continuous to periodic, which fundamentally alters the pump sizing requirements. By controlling the duty cycle of the valve (ratio of open time to total cycle time), the average fluid flow rate into the chamber is reduced, allowing smaller pumps to maintain the same pressure stability that would otherwise require much larger continuous-flow pumps.
Data Source
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AI summary
An interface configured to transfer ions produced at or near atmospheric pressure conditions into a mass spectrometer for mass analysis is provided. The interface includes a first conduit including an inlet configured to receive a fluid containing the ions and an outlet configured to direct the fluid containing the ions into the mass spectrometer. The first conduit defines a first flow path extending from the inlet to the outlet. The interface includes a pump. The interface includes a second conduit. The second conduit includes an inlet. The second conduit defines a second flow path extending from a location between the inlet and the outlet of the first conduit to an outlet of the second conduit. The pump is configured to divert a portion of the fluid including the ions moving in the first flow path to the second flow path.