Selective Multiphoton lonization of Coplanar Polychlorobiphenyls Using 266-nm Laser Emission by Gas Chromatography/Mass Spectrometry

摘要

Polychlorinated biphenyls (PCBs),used as a heat exchange oil (Kanechlor,KC-300),can be measured by gas chromatography combined with multiphoton ionization mass spectrometry (GC/MPI-MS).Several compounds,e.g.,4,4'-dichlorobiphenyl and 3,4,4'-trichlorobiphenyl,have nearly the same retention time but can be selectively determined by MPI-MS.Coplanar PCBs are more efficiently ionized using the fourth harmonic emission of a Nd:YAG laser (266 nm),compared to noncoplanar PCBs.Thus,the approach reported herein may be useful in the selective as well as the sensitive analysis of toxic PCBs,contained in old transformers and capacitors that have been mandated by the government to be properly disposed of within 10 years in Japan.