Phosphite additives and their transformation products in polyethylene packaging for G-irradiation

Abstract

Infrared (IR) spectroscopy has been used to identify and quantify the phosphite antioxidant, tris(2,4-di-tert.butylphenyl) phosphite, and its corresponding phosphate in high density polyethylene (HDPE) food trays, both in the original, commercial trays and also as a function of gamma-irradiation and post-irradiation, storage conditions. This direct method of inhibitor analysis complements time-consuming (some times non-quantitative) extraction methods, which for organo-phosphites are complicated by their facile conversion to phosphates by peroxidic impurities in the solvent. Because of the complete destruction of phosphite to give mainly phosphate at quite low gamma-irradiation doses (approximately 5 kGy) and phosphate formation during melt processing and radiation sterilization of these HDPE trays must take into account products from the irradiation of phosphate. Any residual phosphite is lost progressively in post-irradiation reactions, which are complex, producing a less than-quantitative yield of phosphate.

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.…”

Novel Organophosphate Esters in Airborne Particulate Matters: Occurrences, Precursors, and Selected Transformation Products

“…A portion of the novel OPEs present in airborne particles could also originate directly from consumer products where they were applied as commercial additives, added as impurities along with OPA formulations, or exist as OPAs’ degradation products formed during the manufacturing of consumer products. A number of studies have reported the occurrence of AO168 = O in various consumer products, especially packaging materials for food and pharmaceuticals. − For example, AO168 = O was detected at 50–190 μg/L in the extraction of bag films . To prevent polymer degradation, AO168 plays its role by trapping molecular oxygen to form AO168 = O after the polymer is treated with γ irradiation, UV irradiation, or heat .…”

“…A number of studies have reported the occurrence of AO168 = O in various consumer products, especially packaging materials for food and pharmaceuticals. − For example, AO168 = O was detected at 50–190 μg/L in the extraction of bag films . To prevent polymer degradation, AO168 plays its role by trapping molecular oxygen to form AO168 = O after the polymer is treated with γ irradiation, UV irradiation, or heat . The role of AO168 as an antioxidant could inevitably result in the formation of AO168 = O during the life course of consumer products containing AO168.…”

Antioxidants and their migration into food simulants on irradiated LLDPE film

“…Because the absorbed dose by simulants could be lower than the dose absorbed by PP and the migrated compounds from PP were decomposed into unknown products, the quantities of the migrated compounds in simulants were smaller than those of compounds in PP (Bourges et al, 1992;Bourges, Bureau, & Pascat, 1993). A maximum dose needed to deplete Irgafos 168 in highdensity polyethylene (HDPE) was found to be $7 kGy when measured by the infrared (IR) spectroscopy method (Carlsson, Krzymien, Descheˆnes, Mercier, & Vachon, 2001). 2,4-DTBP from Irgafos 168 in HDPE was detected in the tray samples by thermal desorption, followed by gas chromatography-mass spectrometry (GC-MS) method .…”