Patent ID: 11923182
Assignee: HELMHOLTZ ZENTRUM MUNCHEN DEUTSCHES FORSCHUNGSZENTRUM FUR GESUNDHEIT UND UMWELT (GMBH)
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A method for mass spectroscopic analysis of particles, the method comprising the following steps:
a) with a first irradiation unit comprising an IR laser, irradiating a particle with electromagnetic radiation to cause components of the particle to detach from the particle, the detached components of the particle being located in proximity of a residual core of the particle,
b) with a second irradiation unit comprising a single UV laser, irradiating substantially simultaneously
at least a part of the detached components and the residual core of the particle, with a first beam of electromagnetic radiation from the single UV laser to cause a resonance-enhanced multiphoton ionization (REMPI) or single-photon ionization (SPI) of at least a part of the detached components, the first beam of electromagnetic radiation exhibiting a first intensity, and
at least a part of the residual core of the particle with a second beam of electromagnetic radiation from the single UV laser to cause a laser desorption and non-resonant ionization (LDI) of at least a part of the components of the residual core of the particle, the second beam of electromagnetic radiation exhibiting a second intensity, which is larger than the first intensity, wherein positive ions (+) and negative ions (−) of the detached components and/or of the components of the residual core are accommodated in an ion source region,

wherein the second irradiation unit comprises a focusing optical element configured to generate the second beam of electromagnetic radiation by focusing at least a part of the first beam, the focusing optical element comprising i) a focusing mirror or ii) a planar mirror and a focusing lens, the first beam generated by the single UV laser impinging on both the detached components and the residual core of the particle, the second beam focused by the focusing optical element impinging only on the residual core of the particle, so that the irradiation of the detached components of the particle with the first beam and the irradiation of the residual core of same particle with the second beam occurs substantially simultaneously and both the REMPI or SPI of the detached components of the particle and the LDI of the components of the residual core of the particle is caused by electromagnetic radiation from the single UV laser directed towards the particle as the first beam and reflected by the focusing optical element back towards the particle as the second beam, wherein the single UV laser is directed towards the particle as the first beam by a deflection mirror or the single UV laser is oriented towards the particle, and
c) detecting the positive ions (+) by a first detection channel and detecting the negative ions (−) by a second detection channel.