Investigation of trace p dichlorobenzene using laser mass spectrometry

The time-of-flight mass spectrum (TOFMS) relative to the resonant two-photon ionization of gas phase p-dichlorobenzene was obtained in the wavelength range of 240-250 nm by a home-made system. A special design was made to reduce the effect of memory on the inner wall of the sample inlet system suitable for the investigation of semi-volatile organic compound. In this wavelength range, p-dichlorobenzene molecules firstly absorbed one photon to be excited from the ground state 1Ag(S0) to the first