Alternative sample preparation method for photochemical studies based on solid phase microextraction: synthetic pyrethroid photochemistry.

An alternative sample preparation method for photochemical studies, which overcomes all the disadvantages associated with classical approaches, is proposed. The method is based on Solid Phase Microextraction (SPME) and can be considered as being within the scope of "green photochemistry", especially when it is combined with sunlight irradiation. To demonstrate the potential of the procedure, photochemical studies of synthetic pyrethroids were carried out. Photodegradation pathways for five dihalogenovinyl-substituted pyrethroid pesticides: permethrin, deltamethrin, cyfluthrin, cypermethrin and lambda-cyhalothrin, are proposed, and kinetic curves and parameters provided. This information, obtained by rapidly carried out, green experiments, allows us to corroborate photoproducts reported by other authors and to identify the photoproducts proposed for the first time in the present study.