MS/MS Mass Spectrometer Ion Removal via Adaptive Pulse Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MS/MS type mass spectrometers face challenges in reliably removing unnecessary ions from the collision cell during precursor ion mass-to-charge ratio switching, leading to crosstalk and reduced measurement sensitivity due to incomplete ion removal and contamination issues.
Innovation Solution
The implementation of a lens electrode with a pulse voltage application system, controlled by a means that adjusts the pulse voltage's peak value and width based on the amount of ions remaining in the collision cell, using reverse polarity to accelerate and neutralize ions, ensuring efficient removal and minimizing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pulse voltage is applied to the lens electrode to remove ions from the collision cell, then ion removal efficiency is improved, but lens electrode contamination increases due to ion collision
Solution Approach 1:
The patent applies a pulse voltage with specific parameters (amplitude, width, timing) to the lens electrode to create an electric field that rapidly removes ions from the collision cell. By controlling the pulse voltage parameters, the system achieves effective ion removal while minimizing ion collision with the lens electrode surface, thus reducing contamination.
Solution Approach 2:
The pulse voltage is applied at a specifically timed moment during the ion removal process, before ions can accumulate and collide with the lens electrode. This preliminary action of applying the electric field at the right timing prevents ion adhesion to the lens electrode while ensuring complete ion removal from the collision cell.
2Productivity
If the suspension period between precursor ion scans is shortened to improve throughput, then productivity increases, but ion removal completeness decreases leading to crosstalk
Solution Approach 1:
The patent employs periodic pulse voltage application to the lens electrode during the suspension period. This periodic action creates repeated electric field cycles that efficiently remove ions even within shortened suspension periods, maintaining ion removal completeness while allowing increased measurement throughput between precursor ion scans.
3Speed
If the pulse voltage amplitude is increased to improve ion removal speed, then ion removal efficiency increases, but lens electrode contamination worsens
Solution Approach 1:
The patent optimizes the pulse voltage amplitude to a specific range that provides sufficient electric field strength for rapid ion removal while avoiding excessive amplitude that would cause violent ion acceleration and increased collision with the lens electrode. This parameter optimization achieves fast ion removal speed while minimizing 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 approach effectively eliminates crosstalk and maintains high measurement sensitivity by ensuring complete ion removal, even with varying suspension periods and ion concentrations, thereby improving throughput and reducing lens electrode contamination.
Implementation Method 1
a pulse voltage application system, controlled by a means that adjusts the pulse voltage's peak value and width based on the amount of ions remaining in the collision cell, using reverse polarity to accelerate and neutralize ions
Implementation Method 2
using reverse polarity to accelerate and neutralize ions, ensuring efficient removal and minimizing contamination
Data Source
AI summary
The length of a delay time d from a suspension period starting point t1 until the application of a pulse voltage is begun is changed according to the length of the suspension period during which no data is collected at the time of m/z switching. It is thus ensured that the amount of product ions can be reliably restored at a suspension period termination point t2. In addition, the peak value of the pulse voltage is also changed according to the ionic strength immediately before entering the suspension period. The ion removal rate is thus increased when the amount of remaining ions is high, and the amount of remaining ions is reliably brought to zero within the same pulse width. As a result, crosstalk can be completely removed.