Laser-Desorbed Large Molecules in a Supersonic Jet

A new technique of desorption of non volatile thermally unstable molecules into a supersonic jet has been developped. With this method isolated large molecules are now available for mass spectrometry as well as for spectroscopic studies at temperatures of a few Kelvin, thus avoiding spectral congestion. It could be demonstrated that molecules like tryptophane and retinal could be desorbed with an IR laser pulse without decomposition and be ionized with a second UV laser to form bare molecule ions without fragmentation.