Nano-Tip Photoionization Ion Source for Low-Polar Trace Analysis
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Solution Overview
Problem
Current mass spectrometry techniques face challenges with low ionization efficiency, poor sensitivity, and matrix interference when analyzing trace low-polar compounds in small-volume unicellular samples, particularly in nano-electrospray ionization and atmospheric pressure ionization methods.
Innovation Solution
A nano-liter photoionization mass spectrometry ion source device that includes a nano-tip for sample loading, a metal electrode for high-voltage electric field generation, and a UV lamp for photoionization, optionally housed in a nitrogen-filled chamber to reduce oxygen interference, enhancing the ionization process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nano-electrospray ionization is used for small-volume samples, then ionization efficiency is improved, but detection sensitivity for low-polar compounds deteriorates
Solution Approach 1:
The patent merges nano-ESI and APPI into a single hybrid ion source device, combining the nano-electrospray nozzle for sample introduction with an APPI ionization region containing UV lamp and dopant introduction system. This allows simultaneous utilization of both ionization mechanisms to overcome the limitations of each individual method.
Solution Approach 2:
The patent changes the ionization parameter by introducing dopant substances (such as toluene, acetone, or methanol) that have different volatility and polarity characteristics than the sample matrix. This parameter change enables efficient photoionization of low-polar compounds while maintaining compatibility with nano-ESI sample introduction.
2Reliability
If atmospheric pressure photoionization is used for low-polar compounds, then ionization efficiency is improved, but sample consumption increases
Solution Approach 1:
The patent applies local quality by creating a localized APPI ionization region near the nano-ESI nozzle tip, where dopant and UV irradiation are concentrated only in the immediate vicinity of the sample stream. This localized approach ensures efficient ionization of low-polar compounds while minimizing overall sample consumption.
3Productivity
If conventional ionization methods are used, then analysis speed is maintained, but matrix interference increases
Solution Approach 1:
The patent introduces dopant substances as intermediary compounds that facilitate the ionization process. The dopant acts as a mediator between the UV photons and the low-polar analyte molecules, enabling efficient energy transfer and ionization while reducing direct interaction between the ionization source and the complex sample matrix.
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 solution achieves higher sensitivity and selectivity for low-polar compounds, such as polycyclic aromatic hydrocarbons, with improved signal intensity and signal-to-noise ratios, reducing sample consumption and simplifying the detection process compared to conventional methods.
Implementation Method 1
a UV lamp, configured to emit a high-energy ultraviolet photon to be combined with a gaseous molecule obtained by vaporizing the sample solution, thus achieving a photoionization process
Implementation Method 2
a metal electrode, inserted into the nano-tip to contact with the sample solution directly, thus providing a high-voltage electric field for the nano-electrospray
Implementation Method 3
a small volume of sample solution is injected into a nano-tip and a high voltage (1-2 kV) is applied to the sample solution via electrodes. The sample solution is sprayed out from the end of the nano-tip under a high-voltage electric field
Data Source
AI summary
The present application relates to a nano-liter photoionization mass spectrometry ion source device and an operation method thereof. The nano-liter photoionization mass spectrometry ion source device includes a nano-tip, configured to load a sample solution, thus achieving a nano-electrospray process; a metal electrode, inserted into the nano-tip to contact with the sample solution directly, thus providing a high-voltage electric field for the nano-electrospray; and a UV lamp, configured to emit a high-energy ultraviolet photon to be combined with a gaseous molecule obtained by vaporizing the sample solution, thus achieving a photoionization process. Directed to the problems such as low ionization efficiency, poor sensitivity and more impurity interference existing in the unicellular mass spectrometry process of trace low-polar compounds in small-volume samples, a nano-liter photoionization mass spectrometry ion source device suitable for the analysis on low-polar compounds in small volume, e.g., polycyclic aromatic hydrocarbons (PAHs) is designed in the present application.