UV laser pyrolysis fast gas chromatography/ time-of-flight mass spectrometry for rapid characterization of synthetic polymers: instrument development

摘要

We have designed and developed an instrument that combines a Q-switched Nd:YAG laser, frequency quadrupled to 266 nm, with fast gas chromatography/time-of-flight mass spectrometry (GC/ TOF-MS) for rapid characterization of synthetic polymers. The combined instrument integrates the processes of sampling by the laser, reconcentration of the volatile products, and sample introduction to the GC/TOF-MS. This method uses a UV laser as a fragmentation source, which can create pyrolysis fragments without prior sample pretreatment, even with transparent organic materials. Gaseous pyrolysis products are then concentrated on a cryogenic trap cooled by liquid carbon dioxide and thermally desorbed into the head of the chromatographic column for separation and identification of the components by GC/TOF-MS. Interfacing laser pyrolysis to fast GC/TOF-MS reduces overall analysis time without compromising the chromatographic peak information. This paper describes the design, construction and applications of UV laser pyrolysis-GC/TOF-MS for characterization of synthetic polymer samples. Results from this technique have been compared to conventional heated filament analysis.