ABSTRACT
Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) was applied to the trace analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). To determine the optimum wavelength for analysis of PCDD/Fs, the wavelength of the femtosecond laser utilized for multiphoton ionization was converted to near-ultraviolet status using stimulated Raman scattering. A femtosecond laser emitting at 300 nm completely eliminated the background signal arising from the bleeding compounds generated from a stationary phase of the capillary column in GC.
Subject(s)
Air Pollutants/analysis , Dioxins/analysis , Lasers , Ultraviolet Rays , Air Pollutants/chemistry , Benzofurans/analysis , Benzofurans/chemistry , Dibenzofurans, Polychlorinated , Dioxins/chemistry , Gas Chromatography-Mass Spectrometry , Polychlorinated Dibenzodioxins/analogs & derivatives , Polychlorinated Dibenzodioxins/analysis , Polychlorinated Dibenzodioxins/chemistry , Sensitivity and Specificity , Spectrum Analysis, Raman , Temperature , Time FactorsABSTRACT
The temporal characterization of a femtosecond laser pulse in the deep ultraviolet region using an interferometric autocorrelation scheme is demonstrated. Two-photon ionization of a molecule in a time-of-flight mass spectrometer was used as a nonlinear detector to obtain an autocorrelation trace. This setup proved useful in not only providing a temporal characterization of a pulse but also investigating the ultrafast dynamics of photochemical processes.
