SELECTIVE LASER PHOTOLYSIS OF ORGANIC-MOLECULES IN COMPLEX MATRICES

Laser photolysis was used to eliminate selectively non- desirable (tox ic, carcinogenic, photosensitive) molecules in complex solutions for a pplications in various fields, such as the farm-produce industry, cosm etics, perfumes or biology. The principle of this experiment is based on the tuning of the laser wavelength to an absorption band of the non -desirable molecules which are excited and then dissociated. Destructi on of the molecules is monitored by spectral changes, and photoproduct s can be characterized by gas chromatography and mass spectrometry. Th e advantages of this technique are its rapidity, in situ reaction and quantitative elimination. Examples including the destruction of thujon e in extract of Salvia, bergapten in essential oil of Bergamot, safrol e in essential oil of Sassafras and phycocyanin and phycoerythrin in P orphyridium cruentum are presented and discussed.