Gas chromatography-mass spectrometry (GC-MS) analysis of polymers is often accomplished using an instrument with a pyrolysis attachment.

For laboratories that use GC-MS for numerous applications, installation of a pyrolysis unit is not convenient or budget-friendly. This issue can be resolved by a process known as thermal degradation, in which a polymer sample is placed in a vial and heated until it degrades, releasing distinct volatile fragments that can be collected by solid phase microextraction (SPME).

A cost-efficient and easy setup for the thermal degradation and SPME was created using metal tubing, small glass vials, and a sand bath. A standard method was established to identify any of the three polymers tested in this project, namely polystyrene, polyethylene terephthalate, and high density polyethylene. This method yielded distinguishable GC-MS data even for very small masses (0.00001 g) of each polymer.

Additionally, experimentation was conducted to determine if fine copper wire is a suitable, cost-effective alternative to more expensive SPME fibers. Replacing the fibers with unmodified copper wire did not did not yield GC-MS peaks for most polymer samples.

Research is ongoing to determine whether the copper wires can be modified to allow for SPME of polymer degradation products.

Ezekiel Forster

Wittenberg University

Appearances