TRACE DETECTION OF BENZENE VAPOUR IN A SIMPLE ION CHAMBER EMPLOYING LASER-INDUCED RESONANCE-ENHANCED MULTIPHOTON IONIZATION IN THE 246-264 NM WAVELENGTH REGION

摘要

A tunable, pulsed laser source has been used to ionize trace amounts of benzene vapour ina simple ionization chamber. By scanning the laser wavelength over the B-1(2u)-(1)A(1g) transition of the benzene molecule, it is possible to differentiate the contribution to the total ionization yield due to the resonance-enhanced multiphoton ionization (REMPI) of the benzene sample from that due to background ionization from other unidentified molecular species. The wavelength-dependent ionization fingerprint of benzene is verified by comparison with that of benzene vapour recorded in a laser TOF mass spectrometer. [References: 13]