Quadrupolar mass analysis device

Abstract

Provided is a quadrupole mass spectrometer including direct-current voltage sources (62, 63) having response characteristics which ensure that the response time of the direct-current voltage will be shorter than the period of time required for an ion having the highest mass-to-charge ratio (m / z) among the ions introduced into a quadruple mass filter (2) to pass through this filter (2). Main rod electrodes (31-34) and pre-rod electrodes (41-44) are connected to each other via primary differentiation circuits (65, 66). Thus, in the transient state of the voltage change due to the switching of the mass-to-charge ratio, among the ions entering the quadrupole mass filter (2), ions having low m / z values can be removed by a pre-electrode unit (4), and ions having high m / z values can be removed by a main electrode unit (3). Accordingly, a large amount of ions can be prevented from passing through the filter (2) and entering an ion detector (5).

Description

technical field [0001] The present invention relates to a quadrupole mass spectrometer using a quadrupole mass filter as a mass analyzer for separating ions derived from a sample according to the mass-to-charge ratio (m / z). Background technique [0002] Generally, in a quadrupole mass spectrometer, various ions generated from a sample are introduced into a quadrupole mass filter, and only ions with a specific mass-to-charge ratio are selectively passed through, and the detector is used to detect the ions that pass through. Detection is performed to obtain an intensity signal corresponding to the amount of ions. [0003] The quadrupole mass filter is composed of four rod electrodes arranged parallel to each other around the ion optical axis, and a voltage obtained by adding a DC voltage and a high-frequency voltage (AC voltage) is applied to each of the four rod electrodes. The mass-to-charge ratio of ions that can pass through the quadrupole mass filter depends on the high-...

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