Miniature mass spectrometer

Abstract

The invention discloses a miniature mass spectrometer, in particular comprising an ionization source for converting sample molecules into gas phase ions in a region substantially at atmospheric pressure, a capturing device for capturing and storing ions, and a discontinuous atmospheric pressure interface device for transferring ions from the substantially atmospheric pressure region to at least one further region of reduced pressure. The atmospheric pressure interface device comprises a valve for controlling the ions to enter or stop entering the capturing device, and by opening the valve a plurality of times, ions are conveyed into the capturing device in a discontinuous mode, and the ions are captured and enriched. The miniature mass spectrometer further comprises a mass analyzer, a detector, a circuit, a vacuum cavity, a vacuum pump, a barometer and a computer. The invention provides a miniature mass spectrometer capable of improving sensitivity, ion detection limit and ion strengthstability.

Description

Technical field[0001]The invention relates to the field of micro-mass spectrometers, and more specifically to a micro-mass spectrometer ion introduction device with a discontinuous atmospheric pressure interface.Background technique[0002]Micro mass spectrometers are widely used in some scenes requiring real-time analysis on site. Typical application scenarios include industrial wastewater monitoring, chemical warfare agent detection, pesticide and veterinary drug residue detection in food, and clinical diagnosis.[0003]The atmospheric pressure interface (API) of the mass spectrometer is used to transfer ions from the normal pressure (atmospheric pressure) area to the low pressure area of ​​the vacuum chamber. The application of API makes miniature mass spectrometers have unique advantages compared with laboratory mass spectrometers in field application scenarios, because API allows mass spectrometers to use a variety of ion sources that work at atmospheric pressure, thereby simplifyi...

AI Technical Summary

Problems solved by technology

However, the iontophoresis time of a small mass spectrometer with a DAPI structure cannot be extended arbitrarily

Because once the pinch valve is opened to introduce ions, the air pressure in the vacuum chamber will rise rapidly. In order to maintain the minimum air pressure required by the ion trap plasma capture device in the ion cooling stage and the minimum air pressure required to maintain the normal operation of the turbomolecular pump, the pinch tube The opening time of the valve cannot be extended indefinitely, resulting in a limited number of ions entering the mass analyzer during the opening phase of the valve, which further limits the sensitivity and detection limit of the small mass spectrometer with DAPI structure

In addition, after the pinch valve is opened, ions will enter the vacuum chamber with high-speed airflow, which will negatively affect the mass stability of mass analysis and the stability of ion peak intensity (Huo X, Zhu X, Tang F, Zhang J, Zhang X, Yu Q, et al. Discontinuous Subatmospheric Pressure Interface Reduces the Gas Flow Effects on MiniatureCAPI Mass Spectrometer. Analytical Chemistry. 2020;92(5):3707-15.)

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