Atmospheric pressure ionization mass spectrometer

Abstract

An atmospheric pressure ionization mass spectrometer includes one or more intermediate vacuum chambers between an ionization chamber for generating ions at atmospheric pressure and an analysis chamber for mass separation and detection of ions at high vacuum, wherein: a partition wall separating the ionization chamber from the adjacent first-stage intermediate vacuum chamber or an outlet end of an ion introduction part communicating the two chambers with each other is used as a first electrode; a partition wall separating the first-stage intermediate vacuum chamber and the second-stage intermediate vacuum chamber or the next-stage analysis chamber, or an inlet end of an ion transport portion communicating the two chambers with each other is used as a second electrode; an ion transmission electrode for generating an electric field is arranged in the first-stage intermediate vacuum chamber, and the electric field is used for transmitting the ions while aggregating the ions; and a first voltage setting portion and a second voltage setting portion are also included.

Description

technical field [0001] The present invention relates to the technical field of an atmospheric pressure ionization mass spectrometer, that is, an atmospheric pressure ionization mass spectrometer, in which a liquid sample is ionized substantially at atmospheric pressure, and mass spectrometry is performed under high vacuum as in a liquid chromatography mass spectrometer. Background technique [0002] Liquid chromatography-mass spectrometry (LC / MS) with a combination of liquid chromatography (LC) and mass spectrometry (MS) typically includes an atmospheric pressure ion source using electron spray ionization (ESI), atmospheric pressure chemical ionization (APCI), or other A method of generating gaseous ions in a sample. In an atmospheric pressure ionization mass spectrometer using an atmospheric pressure ion source, the ionization chamber, where ions are generated, is kept substantially at atmospheric pressure, while the contents of the analysis chamber, which contains a mass s...

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Problems solved by technology

[0006] However, this conventional system has a problem that when ions are introduced into the first-stage intermediate vacuum chamber from the ionization chamber maintained at atmospheric pressure through small-diameter capillaries and holes or the like, the ions are cooled due to adiabatic expansion.

Under such conditions, although high dissociation efficiencies are obtained, relatively few cluster ions are generally produced, which may degrade mass or chromatographic spectra and thus make qualitative and / or structural analysis difficult. the substance

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