Analyses of volatile transformation products from additives in gamma-irradiated polyethylene packaging

Abstract

Thermal desorption, followed by gas chromatography (GC) with mass spectrometry (MS) detection, has been found to allow the rapid identification of volatile products resulting from the gamma-irradiation of stabilized, high density polyethylene packaging and pure stabilizers. The stabilizers were tris(2,4-di-tert.butylphenyl) phosphite, octadecyl beta-(2,6-di-tert.butylphenol)-propionate and 2,4-di-tert.butylphenol, the latter resulting from phosphite hydrolysis. Thermal desorption indicated the formation and release of tert.butylbenzenes, such as 1,3-di-tert.butylbenzene upon gamma-irradiation of the HDPE. From a comparison of the products from gamma-irradiation of additive-free polyethylene, of various pure stabilizers and of related compounds, the tert.butylbenzenes were confirmed to result from the irradiation of the phosphite stabilizer and its phosphate conversion product. Thermal desorption off-line, in which volatiles released by a sample are trapped in sorbents for subsequent desorption in the heated GC inlet, is found to be a fast, extremely sensitive method that can be used to guide and supplement analyses of compounds extracted by foodstuffs.

Influence of oxygen and long term storage on the profile of volatile compounds released from polymeric multilayer food contact materials sterilized by gamma irradiation

“…When irradiating (B, C, E, F), the most distinctive feature of gamma ray treated samples is a huge peak of 1,3-ditertbutylbenzene about 10 times higher than the rest of compounds. This fact has been already confirmed by other authors [10,[25][26][27][28], as a degradation product from both phenolic (primary) and phosphite-type (secondary) antioxidants. These are normal components of polyolefin formulations and are easily destroyed by gamma irradiation.…”

Antioxidants and their migration into food simulants on irradiated LLDPE film

“…Upon electron beam irradiation of PP, 2,4-DTBP and 1,3-DTBB were identified as Irganox 168 degradation products when measured by GC-MS and HPLC (Garde et al, 2001;Krzymien et al, 2001;Marque, Feigenbaum, Dainelli, & Riquet, 1998). Similarly, in our study 2,4-DTBP and 1,3-DTBB were detected in LLDPE films as radiolysis products and their concentrations increased with increasing irradiation dose.…”