Abstract
PCBs (polychlorinated biphenyls) are a type of chlorinated aromatic hydrocarbons widely used in condensers and other applications prior to 1970, but now recognized as serious environmental pollutants. "Law Concerning Extraordinary Measures for Promotion of Proper Management of Polychlorinated Biphenyl Waste", which came into effect on July 15,2001, made PCBs disposal mandatory, and many companies are thus engaged in research and development work on PCBs disposal and processing. For protection from PCBs it is necessary to monitor their concentration quite rapidly. But the conventional methods require extensive analytical time (several days per sample) and are not suitable for the above requirement. The objective of the research reported here was to develop the Laser ionization time of flight mass spectrometry (LI-TOFMS) capable of monitoring PCBs within 1 minute. The achievable PCBs sensitivity for real-time (1 minute) measurement was found to be in the ppbV range (0.01 mg/Nm^3) by comparison with the conventional gas sampling / GS-MS (gas chromatograph-mass spectrometry) method. For PCBs, a satisfactory proportional relationship was confirmed between laser-based and conventional results. We examined the exhaust gas measurement using the PCB monitoring system installed in the PCB treatment plant (hydrothermal decomposition). Accordingly, this method implies a useful method for the on-line monitoring of PCBs. In the future we will pursue practical application in the form of a safety management-monitoring device for environmental monitoring.
