Dielectric Barrier Discharge Ionization Without External Ground Electrodes
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Solution Overview
Problem
Existing methods for ionizing gaseous samples using dielectrically hindered discharges can influence analysis devices and require complex electrode configurations, leading to potential short circuits and disturbances in the internal electric field, especially in ion mobility spectrometry.
Innovation Solution
A flexible, bendable capillary with a wire-shaped electrode connected to the high-voltage source is used, eliminating the need for an external ground electrode, allowing the analysis device's housing to act as a capacitor and simplifying the electrical connection, while using a variety of plasma gases and square-wave voltages to enhance ionization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an external ground electrode is used in the dielectrically barriered discharge configuration, then electrical breakdown prevention is achieved, but short circuits and disturbances in the internal electric field occur, particularly in ion mobility spectrometry
Solution Approach 1:
The invention extracts and removes the external ground electrode from the discharge configuration. Instead of using a separate ground electrode outside the capillary, the system relies on the dielectric capillary wall itself to provide the necessary electrical isolation and prevent breakdowns, thereby eliminating the harmful short circuits and electric field disturbances that the external electrode caused
Solution Approach 2:
The dielectric capillary wall serves multiple functions simultaneously: it provides electrical insulation to prevent breakdowns, contains the plasma gas, and eliminates the need for separate ground electrodes. This multi-functionality resolves the contradiction by achieving breakdown prevention without introducing harmful external electrodes
2Power
If two ring electrodes are arranged adjacent to the outlet region of the capillary, then plasma generation is achieved, but the electrode configuration becomes complex and requires extensive insulation
Solution Approach 1:
The invention removes one of the two ring electrodes from the configuration, simplifying the electrode arrangement from a dual-electrode system to a single internal wire electrode. This extraction reduces structural complexity and insulation requirements while maintaining plasma generation capability through the dielectric barrier discharge mechanism
Solution Approach 2:
Instead of placing electrodes outside the capillary as in conventional configurations, the invention inverts the approach by placing a wire electrode inside the capillary. This inversion simplifies the overall configuration by eliminating the need for external ground electrodes and complex external insulation structures
3Power
If the high-voltage electrode is located on the outside of the capillary near the outlet end, then plasma generation is achieved, but interference with the analysis device occurs
Solution Approach 1:
The invention extracts the high-voltage electrode from its position outside the capillary near the outlet and relocates it to the interior of the capillary. This extraction and relocation eliminates the interference with the analysis device while maintaining effective plasma generation through the dielectric barrier discharge
Solution Approach 2:
The invention changes the spatial dimension of electrode placement from external to internal positioning within the capillary. This dimensional change allows the electrode to be positioned in a location that does not interfere with the analysis device while still achieving the desired plasma generation effect
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 significantly improves ionization efficiency, reducing the required sample gas flow from 200-300 ml/min to 10-50 ml/min, and allows for more flexible plasma generation and expansion, avoiding interference with analysis devices.
Implementation Method 1
ionizing gaseous samples by means of a dielectric barrier discharge
Implementation Method 2
the sample ions are generated by a plasma which is caused by a dielectrically impeded discharge
Implementation Method 3
a dielectrically impeded discharge is generated by a plasma gas being introduced into a rear end of a capillary made of a dielectric material
Implementation Method 4
subsequently analyzing the produced sample ions in an analysis appliance, in particular a mass spectrometer or an ion mobility spectrometer
Data Source
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AI summary
The invention relates to a method for ionizing gaseous samples by means of dielectric barrier discharge and for subsequently analysing the produced sample ions in an analysis appliance, in particular a mass spectrometer or an ion mobility spectrometer, wherein the sample ions are produced by a plasma caused by a dielectric barrier discharge, wherein the dielectric barrier discharge is produced by virtue of a plasma gas being supplied through a capillary made of a dielectric material, wherein a wire-shaped electrode is arranged within the capillary, said electrode being connected to an AC voltage source, wherein the gaseous sample is supplied to the exit region of the capillary, wherein the wire-shaped electrode is connected to the AC voltage source on the high-voltage side.