Resonance Ionization Detection of Hazardous Emissions

将研究使用共振增强多光子电离光谱和飞行时间质谱仪(REMPI/TOFMS)连续监测危险废物焚烧炉的烟道气排放。在这项计划中，将调查REMPI/TOFMS方法对从目前已确定的替代品名单中选择的许多物种进行重复在线监测的潜力；这项工作将把对了解分子结构至关重要的详细光谱测量与实际应用该技术所需的检测极限和选择性的测量结合起来。将使用的仪器是一种潜在的便携式采样和检测系统的原型，设想用于焚烧设施的在线实时监测。将特别强调氯化多环芳烃的单色和双色REMPI光谱研究；将对这些物种的振动光谱特征进行分析。由于氯化二苯并二恶英和二苯并呋喃的同系物的形成和销毁预计将遵循类似的途径，因此毒性较小、含量较高的一氯和二氯物种的光谱分析将受到高度重视。由于氯化苯酚同系物对多氯二苯并二恶英和多氯二苯并呋喃的形成很重要，因此还将研究一氯和二氯苯酚的检测限和灵敏度。还将对联苯、对二氯联苯、苯基苯酚(4-羟基联苯)、氯代苯酚、菲和芘的双色R2PI进行选择性和检出限测量。最后，将开展二苯并对二恶英、二苯并呋喃及其几种一氯和二氯同系物的REMPI光谱研究。REMPI的光谱灵敏度可通过样品的喷射冷却实现，消除了传统GC/MS分析程序中耗时的毛细管柱样品分离的需要，这些分析程序被认为不适用于焚烧炉废水的连续排放监测。预计REMPI/TOFMS对包括多环芳香族化合物在内的各类氯化有机物的痕量浓度进行实时在线重复监测的潜力可能有助于解决当前的公众健康问题，并为焚烧炉制定更有效和更简化的许可程序。

Investigation of the use of resonance-enhanced multiphoton ionization spectroscopy and time-of-flight mass spectrometry (REMPI/TOFMS) for the continuous monitoring of stack gas emissions from hazardous waste incinerators will be carried out. In this program, the potential of the REMPI/TOFMS method for repetitive on-line monitoring of numerous species chosen from a list of currently identified surrogates will be investigated; the effort will combine detailed spectroscopic measurements of fundamental importance in understanding molecular structures with measurements of detection limits and selectivities needed for practical application of the technique. The apparatus to be used is a prototype of a potential portable sampling and detection system envisioned for on-line real-time monitoring at an incineration facility. Particular emphasis will be placed on one- and two-color REMPI spectroscopic studies of chlorinated polycyclic aromatics; analyses of the vibronic spectral signatures of these species will be carried out. Since formation and destruction of congeners of the chlorinated dibenzodioxins and dibenzofurans are expected to follow siminar pathways, spectroscopy of the less toxic, more abundant mono- and di-chlorinated species will receive high priority. Due to the importance of chlorinatef congeners of phenol as precursors to the formation of PCDDs and PCDFs, studies of detection limits and sensitivities for mono- and di-chlorinated phenols will also be carried out. Selectivity and detection limit measurements for two-color R2PI of biphenyl, p-dichlorobiphenyl, phenylphenol(4-hydroxybiphenyl), chloro-phenylphenon, phenanthrene, anthracene, and pyrene will also be made. Finally, studies of REMPI spectroscopy of dibenzo-p-dioxin, dibenzofuran, and several of their mono- and di-chlorinated congeners will be carried out. The spectral sensitivity of REMPI, realizable with jet-cooling of the sample, eliminates the need for time-consuming capillary column sample separation of conventional GC/MS analysis procedures which are considered to be impractical for use in continuous emission monitoring of incinerator effluents. It is anticipated that the potential of REMPI/TOFMS for real-time on-line repetitive monitoring of trace concentrations of wide classes of chlorinated organics, including polycyclic aromatic compounds, may help address current public health concerns and produce more effective and simplified licensing procedures for incinerators.