Collision Cell Gas Switching for Stable Vacuum Mass Spectrometry

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Solution Overview

Problem

Conventional ICP-MS systems face inefficiencies in switching between no-gas and with-gas analysis modes, leading to decreased measurement sensitivity and increased analysis time due to vacuum pressure drops and potential contamination, which necessitate temporary voltage discontinuation and prolonged analysis waiting times.

Innovation Solution

A mass spectrometer with a gas supplier featuring a three-way valve and controller that selectively directs the gas flow between a passage for the collision cell and a vacuum passage, preventing sudden gas influx and maintaining stable vacuum conditions during mode switching, allowing continuous voltage application and reduced analysis waiting times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If gas supply is rapidly switched during analysis mode transition, then analysis time is reduced, but vacuum pressure stability deteriorates

Engineering Contradiction:
Improveanalysis timeVSAvoidvacuum pressure stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The system performs preliminary actions before mode switching: closing the gas supply valve in advance before transitioning to no-gas analysis mode, and opening it in advance before transitioning to with-gas analysis mode. These preliminary actions prevent sudden gas influx that would cause vacuum pressure drops, thereby maintaining vacuum stability while enabling rapid mode transitions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system cushions against potential vacuum pressure drops by controlling the gas supply valve timing. By closing the valve before gas influx occurs during mode transition, the system prevents harmful vacuum pressure drops, protecting the vacuum system stability during analysis mode changes.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Object-affected harmful factors

If gas flow rate is increased to prevent air leakage, then contamination is reduced, but vacuum pressure drop increases

Engineering Contradiction:
Improveair leakage contaminationVSAvoidvacuum pressure stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The system closes the gas supply valve in advance before mode transition to no-gas analysis, preventing air leakage contamination during the transition period. By controlling the valve timing, the system maintains gas flow continuity without requiring high flow rates that would cause vacuum pressure drops.

Inventive Principle:
Principle #10Preliminary action

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 minimizes analysis waiting times and improves efficiency by preventing vacuum drops and maintaining stable gas flow, enabling faster and more accurate switching between no-gas and with-gas analysis modes without the need for voltage discontinuation.

Implementation Method 1

a gas supplier including a three-way valve configured to receive a predetermined gas supplied from a gas supply source and selectively send the predetermined gas into either a first passage for sending the predetermined gas to the cell or a second passage for discharging the predetermined gas into vacuum state

Methodology Applied
Scientific EffectGas flow control:

Implementation Method 2

The various kinds of ions introduced into the collision cell repeatedly come in contact with the helium gas. Through every contact with the gas, the kinetic energy possessed by the ions decreases.

Methodology Applied
Scientific EffectCollision:

Implementation Method 3

The ions taken into the chamber are accelerated by a DC electric field and introduced into a collision cell.

Methodology Applied
Scientific EffectElectric field acceleration: Electric Field

Implementation Method 4

The neutral particle is dissipated to the outside of the collision cell, without being captured by the radio-frequency electric field created by the ion guide located within the collision cell.

Methodology Applied
Scientific EffectRadio-frequency electric field: Electromagnetic Induction

Implementation Method 5

The interfering ion whose m/z has changed, or an ion originating from this ion, is separated from the target ion in a quadrupole mass filter or similar mass separator in the subsequent stage.

Methodology Applied
Scientific EffectMass filtration: Electric Field

Data Source

PatentEP4362060A1Mass spectrometer
Publication Date: 2024.05.01 SHIMADZU CORP
  • EP4362060A1 patent drawingFigure 1~2
  • EP4362060A1 patent drawingFigure 3~4
  • EP4362060A1 patent drawingFigure 5

AI summary

Provided is a mass spectrometer including a vacuum chamber containing a cell used for causing ions originating from a sample to come in contact with a predetermined gas supplied from a gas supplier (20), which includes a three-way valve (204) configured to selectively send the gas into either a first passage (22) for sending the predetermined gas to the cell or a second passage (23) for discharging the gas into vacuum state. The mass spectrometer also includes a controller configured to control the three-way valve so as to send the gas into the second passage during an analysis period in which ions are not caused to come in contact with the gas within the cell and/or during a non-analyzing period, as well as to send the gas into the first passage during an analysis period in which ions are caused to come in contact with the gas within the cell.