Radiation treatment of various food and food contact materials are approved in the US to increase food shelf life and improve food safety. Irradiation doses for most of food and food packaging are limited to doses less than 10 kGy, with few exceptions such as spices which can be treated at doses less than 30 kGy. With increasing demand of prepackaged food and food safety, there is a possibility of increased use of irradiation technology. During irradiation, radiolysis products may form from the polymer additives found in food contact materials. Most irradiation studies on polymer additives involve radiation doses higher than 10 kGy. The focus of this study is to investigate the changes in the concentration of the polymer additives, specifically antioxidants, and determine the major radiolysis products from the antioxidants when polyethylene resin material is exposed to gamma irradiation doses of 0.5 - 20 kGy. The antioxidants are extracted by accelerated solvent extraction, and analyzed by LC-MS with atmospheric pressure chemical ionization. Chromatographic separation is achieved using C8 and C18 columns with methanol and water as mobile phases. Percent recoveries of the antioxidants and method detection limits were determined. A decrease in the amount of antioxidants is observed as the irradiation dose is increased. For Irganox 1076, a 39% decrease from 415 ppm is observed at 4 kGy. The major radiolysis product is an oxidized form of Irganox 1076 corresponding to the loss of two hydrogens. Studying the formation of these radiolysis products will help in exposure based safety evaluation of food contact materials used with food irradiation at low doses.

LC-MS analysis of antioxidant polymer additives exposed to low dose gamma irradiation

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.