Automated Analysis of Persistent Organic Pollutants in the Gas Phase by Laser Ionization Mass Spectrometry

Abstract

Persistent organic pollutants (POPs) are toxic chemicals that adversely a#ect human health and the environment around the world. The detection and evaluation of small amounts of POPs require methods with both high precision and high chemical selectivity. Conventional methods involve a number of preparatory steps and time-consuming analysis and are not suitable for the abovementioned purposes. Hence, new automated analysis methods are required for on-line detection and rapid analysis of POPs. In this paper, mass spectrometry with resonance-enhanced multi-photon ionization (REMPI) is performed to obtain information about the automated analysis of POPs in the gas-phase with on-line detection. Dynamic trapping time-of-flight mass spectrometry (TOFMS) was performed with su$cient selectivity and sensitivity for rapid analysis of polychlorinated biphenyls (PCBs) in the gas phase. Compared to normal trapping, the use of dynamic trapping enabled ion signal intensity to be increased by a factor of greater than 10. The detection limit at 1 min was ῍1 ppbV, and the accuracy also correlated well with the results of conventional analysis. Based on these results, an automated monitoring system was developed for automated analysis of PCBs. It was confirmed that this monitoring system was capable of analyzing PCB concentration without being influenced by main gas components or various coexisting substances, even under conditions characterized by exhaust gas and the work environment atmosphere. PCB concentration in PCB waste plants, which is substantially lower than the 0.10 mg/m 3 N specified in statutory regulations, could be analyzed within 1 min. It was possible to make continuous long-term analysis for over 2,000 h (120,000 points).