title: Multiphoton ionization mass spectrometry of chlorophenols as indicators for dioxins.
abstract: Mono-, di- and trichlorophenols were measured using resonance-enhanced multiphoton ionization mass spectrometry (MPI-MS) combined with supersonic jet (SSJ) or effusive molecular beam (EMB) spectrometry. All mono- and dichlorophenols, except 2,6-dichlorophenol, provided sharp and structured MPI spectra for the S1 <-- S0 transition. Selectivity and sensitivity were both enhanced when SSJ spectrometry was used, compared with EMB spectrometry, because of a narrower linewidth in the MPI spectrum, given by molecular cooling by supersonic jet expansion. The ionization efficiency decreased with increasing number of chlorine substituents for the chlorophenols, since they have shorter excited-state lifetimes and require three photons for ionization. Some of the chlorophenols, which are toxic themselves, have the potential for use as indicators for analysis of polychlorinated dibenzo-p-dioxin/dibenzofurans in flue gases emitted from an incinerator.
authors.affiliation: Department of Chemical Science and Technology, Faculty of Engineering, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Uchimura
authors.forename: Klaus
authors.initials: K
authors.lastname: Hafner
authors.forename: Ralf
authors.initials: R
authors.lastname: Zimmermann
authors.forename: Totaro
authors.initials: T
authors.lastname: Imasaka
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D002733:Chlorophenols / Q000032:analysis* / Q000737:chemistry*; D004147:Dioxins / Q000032:analysis* / Q000737:chemistry*; D007220:Industrial Waste / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D000393:Air Pollutants; D002733:Chlorophenols; D004147:Dioxins; D007220:Industrial Waste