IDENTIFICATION BY PARTICLE-BEAM LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY OF TRANSFORMATION PRODUCTS OF THE ANTIOXIDANT IRGANOX-1330 IN FOOD-CONTACT POLYMERS SUBJECTED TO ELECTRON-BEAM IRRADIATION

Transformation products of Irganox 1330 [1,3,5-trimethyl-2,4,6-tris(3',5',di-tert.-butyl-4-hydroxybenzyl)benzene] in food contact polymers subjected to electron-beam irradiation have been analysed by particle-beam LC-MS. It has been shown that the principal degradation products arise via (1) oxidation of hindered phenol groups to give compounds having quinone methide structures or (2) cleavage of tert.-butyl groups or (3) cleavage of hindered phenol sub-units or (4) combinations of the above processes. Whilst quinone-methide-derived oxidation products are also observed in related thermally oxidised samples, products arising from the cleavage of tert.-butyl groups are only detected in irradiated samples.