Gas chromatography/mass spectroscopy for plastics failure analysis

Gas chromatography/mass spectroscopy is particularly useful as an analytical method for plastics failure analysis in cases where detection of an unknown contaminant or other compositional factor may be the cause or a contributor to failure. It takes advantage of the fact that GC is a method of separating compounds in a mixture, permitting their identification and possibly quantification. MS is not only a very sensitive detector but also gives mass spectra of GC peaks, permitting their identification in many cases. In thermal desorption GC/MS compounds are transferred from the sample to the GC with heat. Completely nonvolatile materials are not detected. Using desorption temperatures up to 300-350 °C, many components of plastics can be analyzed. In pyrolysis GC/MS the sample is decomposed at temperatures up to 900 °C; GC/MS analyzes the pyrolyzate. Examples are given of causes of plastics failures that have been determined by GC/MS.