Device for studying macromolecular ion photoelectron spectrum

Abstract

The invention relates to the field of spectrochemistry, and relates to a device for studying a macromolecular ion photoelectron spectrum. The device comprises a vacuum cavity, a droplet ejector, an ion buncher, a quadrupole mass filter, an ion trap, an air inlet, an exit lens, a shield cover, a speed imaging disk, a laser, a multi-channel disk, a detector, a computer, an input / output module, fieldprogrammable logic device, a digital-to-analog conversion module, a high-voltage power supply, a drive circuit and a vacuum pump set. A method of resonance of a drive unit and liquid is utilized to eject droplets; a vibration direction of the drive unit is parallel to a droplet ejecting direction, so that the device can form uniform droplets with relatively small size, has no special requirementfor a solvent, does not need to apply a high voltage to the solution during ejection, is applicable to a wider range of macromolecular species, utilizes a digital trapezoidal waveform voltage to drivethe quadrupole mass filter, obtains a charge-to-mass ratio spectrum by scanning the frequency, can measure particles with a relatively large charge-to-mass ratio, can minimize harmonics in the voltage, and obtains a relatively high signal resolution.

Description

technical field [0001] The invention relates to the field of spectrochemistry, in particular to a device for studying the photoelectron spectrum of macromolecular ions, which can be used for the research of many kinds of macromolecular ions, in particular, which can analyze ions with large charge-to-mass ratio. Background technique [0002] The device for studying molecular photoelectron spectroscopy studies the ion beam current of the molecule to be measured in a vacuum environment. It is usually necessary to atomize the solution containing the sample to be tested and then enter the vacuum environment. In addition, it usually has a mass filter to select different charges in the ion beam current. quality ratio of ingredients. The quadrupole mass filter used for ion beam filtration in vacuum usually consists of four cylindrical metal rods of the same size. The metal rods are parallel to each other and symmetrical about the central axis of the ion path. Conduction, connected ...

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Problems solved by technology

The quadrupole mass filtration method cannot usually be used to analyze ions with high charge-to-mass ratio. In order to increase the maximum charge-to-mass ratio that can be measured, the frequency of the radio frequency signal must be reduced, that is, a new resonance circuit is required. However, the resolution power depends on The number of radio frequency cycles that ions pass through the quadrupole mass filter. Therefore, the method of reducing the frequency of the radio frequency signal will reduce the resolution power. In addition, reducing the frequency of the radio frequency signal will also reduce the ion beam at the exit of the quadrupole mass filter. The area of ​​the cross section, promptly reduces the signal strength of ion; The improved method is to obtain the charge-mass ratio spectrum by fixing the quadrupole mass filter driving voltage and performing frequency scanning. The extreme mass filter adopts a sinusoidal driving voltage, which contains a large number of harmonic voltages, and the ringing effect generated is strong, resulting in distortion of the voltage waveform, and the accuracy of the obtained charge-mass ratio spectrum is not high; defect 2 of the prior art: a certain Some devices use the electrospray method to atomize the solution containing the sample to be tested. There are certain requirements for the solvent in the solution, that is, it must be a polar solution, and a high voltage must be applied to the liquid when the electrospray is working, which limits the electrospray solution. The type of sample to which the method is applicable; the third defect of the prior art: some devices in the prior art make the liquid spray out and form droplets by directly applying pressure to the liquid, and the size of the droplets produced by this method is limited by the size of the liquid. inner diameter of the droplet ejection, i.e. the inability to form smaller droplets, a device for studying photoelectron spectroscopy of macromolecular ions can solve the problem

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