Isomer-selective ionization of chlorinated aromatics with lasers for analytical time-of-flight mass spectrometry: First results for polychlorinated dibenzo-p-dioxins (PCDD), biphenyls (PCB) and benzenes (PCBz)

The combination of laser induced Resonance-Enhanced Multi-Photon Ionization (REMPI) and Time-Of-Flight mass spectrometry (TOF) represents a useful tool for detection of trace quantities of organic substances. REMPI spectra (i.e. laser UV spectra) as well as laser induced mass spectra of several aromatic compounds are presented. The possibility of isomer-selective ionization is demonstrated by REMPI ionization spectra of isomeric compounds: Spectra of three dichlorodibenzo-p-dioxin isomers, three tetrachlorobenzene isomers and three dichlorobiphenyl isomers are shown. Finally the potentiality of laser mass spectrometry in the field of environmental analysis is discussed.