Resumen de Use of a Dynamic Headspace GC-MS Method for the Study of Volatile Organic Compounds in Polyethylene Packaging. An Undergraduate Experiment in Polymer Analysis

Steven C. Hodgson, R. John Casey, John D. Orbell, Stephen W. Bigger

• 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.