Molecular beams of polyenes: Retinals and β-carotene

Low temperature, molecular beams of polyenes (retinol, retinal, a Schiff base retinal, and β-carotene) are formed in jet expansions by CO2 laser-induced desorption from a deposited solid surface. Mass spectra of these intact polyenes are detected by resonantly-enhanced ionization mass spectrometry. Laser-desorption conditions which produce essentially no polyene fragmentation are obtained by controlling the focusing conditions of the CO2 laser on the deposited sample.