Communication. Polymer characterization using laser desorption–ion mobility spectrometry
A series of polymer composite materials has been classified using laser desorption–ion mobility spectrometry. The pulse from an Nd: YAG laser ablates the surface of the composite polymer generating molecular fragments in the vapour phase that are representative of the target material. These vapour phase components are drawn into the ion mobility spectrometer source where they are ionized. Both positive and negative ions are formed and the spectrometer can operate in either mode. The ions are resolved into a pattern or signature characteristic of the polymer. As the spectrometer can sample at a rate of approximately 1 s–1 a rapid method of identifying polymers results. Similar materials such as high and low density polyethylenes can be differentiated in this way.