Laser pyrolysis gas chromatography system using a pulsed Nd: YAG laser and its analytical performance

Abstract

A laser pyrolysis gas chromatograph (LPGC) system has been developed, which allowed for the direct analysis of solid samples. The LPGC system consists of a Q-switched Nd : YAG laser (pulse energy, 0 230 mJ ; repetition rate, 1 15 Hz) as a fragmentation source, a gas chromatograph, a sample chamber, and a data-acquisition/processing system. A commercial tube-furnace type pyrolyzer was used as the sample chamber, and the sample was placed in a quartz tube. The LPGC system was applied to the analysis of a polystyrene sample, and its analytical performance were investigated. The chromatographs obtained from polystyrene showed the characteristic component peaks of ethylene, benzene, toluene, and styrene monomer. The relative standard deviations of the peak intensity, the FWHM, and the retention time were in the ranges of 5.3 22 , 3.1 16 , and 0.06 1.1 , depending on the components, respectively. The effects of the laser energy and laser focusing on the chromatograms were investigated. The results showed that moderate energy and defocusing of the laser radiation brought about an increase in the signal intensity.