One of the problems in an HPLC laboratory is the preservation of samples and extracts prior to analysis without any changes. It has been found that degradation processes cannot be eliminated entirely, but they can be slowed down considerably. Photodegradation kinetics of fluorene, anthracene and benzo(a)pyrene were studied in various organic solvents. Solvents known as good media to store PAHs for a long time were selected with respect to avoid degradation. In the case of fluorene, 9-fluorenone and 9-hydroxyfluorene were detected as main photoproducts. Formation of anthraquinone and 1,8-dihydroxyanthraquinone during the degradation of anthracene was observed. Benzo(a)pyrene-4,5-dihydrodiol and one of the isomers of hydroxy-BaP-dione as products of benzo(a)pyrene photodegradation have been identified.