The observation of biomolecules in the gas phase is a
unique means to unravel their intrinsic physical and chemical
properties. It allows for their detection in the absence
of perturbation, for the use of sophisticated detection
methods such as mass spectrometry or photoelectron spectroscopy
and direct comparison with quantum chemical
calculations. However, the main problem is to bring intact
in the gas phase such complex and fragile molecules. This
can be achieved by several methods: direct heating, laser
desorption or electrospray. We have used here laser vaporisation
from a mixed graphite–vitamin B12 pellet in a similar
fashion to Piuzzi et al. [1]. The graphite matrix is laserheated
and desorbs the B12 molecule which is rapidly
cooled in a supersonic expansion.
Vitamin B12 or cyanocobalamin (C63H88CoN14O14P