A two-stage differential ion funnel for transporting outgoing ions

Abstract

The invention discloses a two-stage differential ion funnel for transmitting outgoing ions, including a first-stage ion funnel, a first extraction and binding electrode, a second-level ion funnel, and a second extraction and binding electrode; A circular electrode is arranged inside the rectangular electrode sheet. The inner holes of several electrode sheets in the first-level ion funnel form a cylindrical, spiral or conical ion channel in turn; the inner holes of several electrode pieces in the second-level ion funnel form a conical ion channel in turn; the rear end of the first-level ion funnel There is a first extraction-binding electrode for controlling ion divergence, and a second extraction-binding electrode for controlling ion divergence is located at the rear end of the secondary ion funnel. The ion funnel electrodes apply DC and AC voltages, and the extraction-binding electrodes apply only DC voltages. The two-stage ion funnel involved in the present invention has small capacitance, and can limit the divergence of outgoing ions and regulate the kinetic energy of outgoing ions while realizing high-efficiency transmission of ions.

Description

technical field [0001] The invention relates to the technical field of mass spectrometry, in particular to a two-stage differential ion funnel for transmitting outgoing ions. Background technique [0002] Mass spectrometry is one of the important experimental techniques for analyzing the composition of pure matter, analyzing photolysis products and studying the kinetic mechanism of photochemical reactions. Electrospray ionization (ESI) is a newly developed soft ionization technology that generates gas-phase ion sources, and is widely used in the field of mass spectrometry. Electrospray technology is used to generate ion sources. During the transmission of ion beams to ion analyzers, some ions will be lost due to collisions with neutral molecules, electric field distortion, etc., which reduces the number of ions that can reach the analyzer and reduces the The ion enrichment efficiency of the mass spectrometer increases the difficulty of the experiment. In order to solve the...

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Problems solved by technology

The traditional ion funnel structure cannot effectively screen particles such as large-mass droplets and neutral molecules, which affects the cleanliness of the next-level vacuum chamber and reduces the sensitivity and efficiency of subsequent experiments.

In order to solve the above problems, Kim et al. proposed an ion funnel with a jet disrupter structure, which replaces one electrode of the equal-diameter electrode part in the traditional ion funnel with a metal circular baffle electrode whose diameter is smaller than the inner diameter of the electrode. , the baffle is placed coaxially with the ion funnel electrode to achieve the filtration of neutral particles, but this structure will greatly reduce the ion transmission efficiency of large mass-to-charge ratios

The V-shaped ion funnel designed by Deng et al. is to stack the equal-diameter circular electrodes in the middle of the ion funnel to form a "V" shape, so as to achieve the filtration of large-mass neutral droplets. Since the electric field of this structure is in the "V There is a large distortion at the "shaped corner, which makes it difficult to effectively control the trajectory of ordinary ions and reduces the transmission efficiency of ions.

In addition, the traditional ion funnel cannot effectively control the divergence angle and kinetic energy of the outgoing ions at the rear end, which makes the transmission, focusing and mass analysis of subsequent ions more experimentally difficult.

At the same time, the overlapping area between the traditional ion funnel electrodes is relatively large, which increases the total capacitance of the ion funnel and makes it difficult to match the high-frequency radio frequency voltage.

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