Radiolysis products in gamma-irradiated plastics by thermal desorption-gas chromatography-mass spectrometry

Low-molecular-weight ('volatile') radiolysis products of polymers were investigated by thermal desorption-gas chromatography-mass spectrometry (TDS-GC-MS), a technique comparable to dynamic headspace analysis. The experiments have a two-fold background, namely, radiation sterilization of medical products and packaging in food irradiation; the main objectives were (1) to allow a better assessment of the risks potentially associated with these techniques (safety evaluation), and (2) to evaluate whether thermal desorption allows to distinguish between irradiated and non-irradiated materials (irradiation detection). The volatiles were analyzed with commercially available equipment that uses a cooled injection system (CIS; a PTV-type split/splitless injector) to interface the TDS-unit with the GC column. After a qualitative screening of six medical polymers aimed at identifying the volatiles produced by a sterilizing dose of ca. 25 kGy, and a digression into LDPE and polypropylene films (inspired by some rather unexpected results), it was decided to focus the investigation on polystyrene (PS), and - as a third major objective - to quantify the major radiolysis products of PS. (orig.)Available from: http://edocs.tu-berlin.de/diss/2000/ / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman