Electrospray Ionizer Layout for Stable Desolvation and Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing ionization methods in liquid chromatograph mass spectrometers, which use heated gas to promote desolvation, destabilize the nebulization process and result in unstable ion measurement sensitivity due to heating of the liquid sample within the ESI probe.
Innovation Solution
An ionizer design where a heated gas is blown onto charged droplets at a position orthogonal to the nebulization axis and separated from the ESI probe tip, promoting desolvation without boiling the liquid sample and reducing contamination in the analysis chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heated gas is blown around the tip of the ESI probe to promote desolvation, then desolvation efficiency is improved, but the liquid sample in the capillary is heated and may be boiled, destabilizing nebulization and ion measurement sensitivity
Solution Approach 1:
The heated gas supply mechanism is positioned to extract the heating function away from the ESI probe tip area, directing heated gas to a location downstream where charged droplets have already formed. This separation prevents the heated gas from contacting the liquid sample in the capillary, eliminating the boiling issue while maintaining desolvation efficiency.
Solution Approach 2:
The invention changes the spatial dimension of heated gas application by positioning the heated gas supply mechanism at a location separated from the ESI probe tip in the direction of droplet flight. Instead of heating at the source (probe tip), heating occurs downstream in the droplet flight path, fundamentally changing where and how heating is applied to resolve the contradiction.
2Productivity
If heated gas is blown to charged droplets to promote desolvation, then ionization efficiency is improved, but contamination of the ion introduction port and analysis chamber increases
Solution Approach 1:
The heated gas supply mechanism is positioned to provide localized heating only to the charged droplets in the flight path, rather than heating a broad area that would include the ion introduction port and analysis chamber. This localized approach promotes desolvation and ionization efficiency while preventing contamination of sensitive components.
3Temperature
If heated gas is blown close to the ESI probe tip, then desolvation of charged droplets is enhanced, but the liquid sample flow through the capillary is heated and nebulization becomes unstable
Solution Approach 1:
The invention applies heated gas after the liquid sample has already been nebulized into charged droplets, rather than heating the liquid sample before nebulization. This preliminary nebulization step creates charged droplets that can be heated without affecting the liquid flow stability in the capillary, as the heating occurs after the critical nebulization process has already taken place.
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 design enhances desolvation efficiency, improves ion measurement sensitivity, and reduces contamination by ensuring that ions enter the analysis chamber in a stable state, thereby increasing the robustness of the device.
Implementation Method 1
an electrospray ionization probe configured to charge and nebulize a liquid sample as charged droplets
Implementation Method 2
the nebulized charged droplets are further micronized in the ionization chamber by repeating a process in which the surface electric field increases with evaporation (desolvation) of the solvent and are split by repulsion between charges
Implementation Method 3
a heated gas supply mechanism configured to blow a heated gas to a position between a tip of the electrospray ionization probe and an intersection point of the nebulization axis and the central axis
Implementation Method 4
blowing a heated gas to charged droplets immediately after nebulized from the probe
Implementation Method 5
Ions generated in the ionization chamber are drawn into a mass spectrometry chamber from an ion introduction port provided in a partition between the ionization chamber and the mass spectrometry chamber by a pressure difference between the ionization chamber having a substantially atmospheric pressure and the mass spectrometry chamber which is a vacuum chamber
Data Source
AI summary
An ionizer disposed in an ionization chamber separated from an analysis chamber by a partition provided with an ion introduction port, the ionizer including: an electrospray ionization probe 111 configured to charge and nebulize a liquid sample as charged droplets, the electrospray ionization probe being disposed such that a nebulization axis is orthogonal to a central axis of the ion introduction port; and a heated gas supply mechanism configured to blow a heated gas to a position between a tip of the electrospray ionization probe and an intersection point X of the nebulization axis and the central axis, where the position is separated from the tip by a predetermined distance or more.