Membrane Purge Gas Transfer for Stable Laser Ablation ICP Analysis
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Solution Overview
Problem
Existing laser ablation systems face issues with atmospheric gases entering the inductively coupled plasma (ICP) torch during sample changeover, leading to plasma extinction and increased operational costs due to frequent mechanical failures and maintenance needs of pinch valves.
Innovation Solution
A gas exchange membrane transfer line is used to replace atmospheric gases with a sweep gas, such as argon, without the need for physical clamps or restrictions, ensuring continuous operation of the ICP torch by fluidically coupling the laser ablation system with the analysis system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pinch valves are used to prevent atmospheric gases from entering the ICP torch, then plasma stability is improved, but device complexity and maintenance needs increase
Solution Approach 1:
The patent removes the pinch valve from the system entirely and replaces it with a membrane-based gas exchange mechanism. The membrane allows selective gas permeation without requiring mechanical valves, thereby extracting the problematic component while maintaining plasma stability through controlled gas exchange.
Solution Approach 2:
The patent introduces a membrane as an intermediary component between the sample transfer stream and the ICP torch. This membrane selectively allows certain gases to pass through while blocking others, serving as a passive mediator that maintains plasma stability without requiring active valve control.
2Reliability
If pinch valves are used to control gas flow during sample changeover, then plasma extinction is prevented, but operational costs and maintenance frequency increase
Solution Approach 1:
The membrane system operates passively based on gas permeation properties and pressure gradients, requiring no external control mechanisms or maintenance. The system self-regulates gas flow to prevent plasma extinction during sample changeover without requiring operator intervention or component replacement.
Solution Approach 2:
The patent replaces the mechanical pinch valve system with a physicochemical membrane-based system. Instead of using mechanical components that wear and require maintenance, the system uses the inherent selective permeability properties of the membrane material to control gas flow and maintain plasma continuity.
3Device complexity
If atmospheric gases are allowed to enter the ICP torch during sample changeover, then device complexity is reduced, but plasma extinction occurs and productivity decreases
Solution Approach 1:
The patent uses an inert or controlled atmosphere approach by allowing only specific gases (such as helium or other inert carrier gases) to pass through the membrane while blocking atmospheric gases. This creates a protective gas environment that prevents plasma extinction and maintains continuous operation during sample changeover.
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
The system effectively purges atmospheric gases, maintaining plasma stability and reducing downtime and maintenance costs by ensuring over 99% gas exchange, thus enhancing sample throughput and analysis consistency.
Implementation Method 1
a gas exchange membrane transfer line configured to replace gas in the sample transfer stream with sweep gas via gas exchange across a membrane of the gas exchange membrane transfer line
Implementation Method 2
ablating a portion of the target with one or more laser pulses to generate a plume containing particles and/or vapor ejected or otherwise generated from the target
Implementation Method 3
a plasma containing the ionized particles and/or vapor is then analyzed by an analysis system
Implementation Method 4
inductively coupled plasma (ICP) torch where it is ionized
Data Source
AI summary
Systems and methods are described for transferring gas from an ablation cell to an inductively coupled plasma analysis system via a gas exchange membrane transfer line to exchange gas introduced to the ablation cell with a sweep gas. A system embodiment includes, but is not limited to, a laser ablation cell configured to generate a sample transfer stream through laser ablation of a sample and introduction of a carrier gas to flow the ablated sample from the laser ablation cell; an inductively-coupled plasma analysis device configured to measure one or more analytes in the sample transfer stream; and a gas exchange membrane transfer line fluidically coupled between the laser ablation cell and the inductively-coupled plasma analysis device, the gas exchange membrane transfer line configured to replace gas in the sample transfer stream with sweep gas via gas exchange across a membrane of the gas exchange membrane transfer line.