No abstract

No abstract

The formation of volatile organic compounds (VOCs) in polyethylene (PE) is a topic of concern to industries involved in the packaging of items such as foodstuffs and pharmaceuticals that are sensitive to organoleptic contamination. This article reviews the available literature on VOCs that originate from PE during its manufacture, processing, storage, and service life. The package-product interactions that may occur between PE and packaged foodstuffs are also considered together with the wide range of methods for the analysis of VOCs. The following analytical methods are discussed: (i) sensory evaluation, (ii) chromatographic techniques and their associated sampling techniques, including ORDER REPRINTS the "hot-jar" method and dynamic headspace sampling, (iii) gas chromatography-olfactory sensing, and (iv) artificial olfaction or "electronic nose" technology.

A novel experiment is described for introducing senior undergraduate physical chemistry and food science students to a technique commonly used to identify volatile organic compounds (VOCs) that are emitted from polymers at ambient temperatures. The VOCs in food-grade low-density polyethylene (LDPE) pellets are purged with nitrogen and trapped at ambient temperature on a Tenax-GC (2,6-diphenyl-p-phenylene oxide polymer) sorbent. The VOCs are liberated using dynamic headspace desorption and are separated and identified using the technique of gas chromatography-mass spectrometry (GC-MS). The relationship between the chromatographic peak area of a given VOC and the temperature of desorption, as well as the relationship between the total chromatographic area and the temperature of desorption, are quantitatively modeled using a modified form of the van't Hoff isochore.

No abstract