Infrared Mass spectrometry Imaging

We are developing a new approach coupling IR spectroscopy and mass spectrometry.

The new method (AIRLAB-MS) combines an atmospheric ionization device and a FTIR-Microscope. The two devices together will permit the use of nondestructive IR imaging to determine the region of interest and then using an ablation laser on this region the sample evaporates and will be fully characterized by mass spectrometry.

airlab_principle_web

Fig 1 : AIRLAB Principle

 

For that, an AIRLAB (for Ambient Infrared Laser Ablation Mass Spectrometry) has been installed into the infrared microscope of the beamline 1.4.4 at the ALS. This consist (See Fig 1) of an OPO infrared laser that hit the sample through the microscope. The high among of energy deposited leads to the creation of a plume composed of the sample material. This plume is caught by a liquid droplet (solvent) continually flowing to a macro-spray source that ionizes the sample. The generated ions are then identified by mass spectrometry (Q-Tof)

Fig 2 : Optic principle of AIRLAB and FTIR

Fig 2 : Optic principle of AIRLAB and FTIR

In order to change between Infrared Imaging (FTIR) and Mass spectrometry (by laser ablation) a motorize switch mirror is installed between the ablation laser and the FTIR, this allows to switch quickly between the two modes and the guarantee a perfect alignment of the two technics (See Fig 2).

Publications :

  • Masson, A., O’Brien, J. T., Williams, E. R., & Holman, H.-Y. N. (2017). Towards Integrating Synchrotron FTIR Microscopy with Mass Spectrometry at the Berkeley Synchrotron Infrared Structural Biology (BSISB) Program. Synchrotron Radiation News, 30(4), 17–23. http://doi.org/10.1080/08940886.2017.1338418

  • O’Brien, J. T., Williams, E. R., & Holman, H.-Y. N. (2015). Ambient Infrared Laser Ablation Mass Spectrometry (AIRLAB-MS) of Live Plant Tissue with Plume Capture by Continuous Flow Solvent Probe. Analytical Chemistry, 87(5), 2631–2638. http://doi.org/10.1021/ac503383p