MRI: Development of a LASER Sensor for the Measurement of Elemental and Reactive Gaseous Mercury

首席研究员（pi）将开发一种新型激光传感器，用于检测气相元素汞、Hg(0)和活性气态汞（RGM）。该仪器将基于单个50 Hz Nd-Yag激光器，该激光器将用于泵送两个紧凑的染料激光器。pi的初步努力表明，这项技术是可行的。完成后，该仪器将能够以时间分辨率和精度测量气态元素汞，从而允许使用涡流相关技术进行Hg(0)通量测量。当该仪器配置为测量Hg(0)的原位采样时，将达到与当前仪器相匹配的检测限，但在更短的时间内。这种在时间分辨率和检测方法上的改进，与目前在飞机平台上测量Hg(0)的方法相比，具有显著的优势。同样的仪器可以重新配置，以操作与denuders预采样的RGM采样。与目前的方法相比，这将有可能大大减少采样时间，并提供获得良好分辨率的RGM日剖面所需的时间分辨率。它还显示了利用可编程热分解/解吸从剥蚀物形成RGM的前景。该仪器将主要用于研究和研究训练，但它将整合到教育活动中，并将改善迈阿密大学的科学家、研究生和本科生对最先进激光系统的接触，并增加其访问和使用。准确测量元素和活性气态汞的化学形态和沉积速率的能力对监管政策和美国清洁空气汞规则的实施具有重要意义。

The Principal Investigators (PIs) will develop a novel laser based sensor for the detection of gas phase elemental mercury, Hg(0),and reactive gaseous mercury (RGM). The instrument will be based on a single 50 Hz, Nd-Yag laser that will be used to pump two compact dye lasers. Preliminary efforts by the PIs have shown this technology to be feasible. Upon completion, the instrument will be capable of measuring gaseous elemental mercury with a temporal resolution and precision that will allow for Hg(0) flux measurements to be made using the eddy correlation technique. The instrument, when configured for in-situ sampling for measurement of Hg(0) will achieve detection limits which match those of current instrumentation but in a significantly shorter time period. This improvement in temporal resolution and the detection approach offer significant advantages over current approaches for measurement of Hg(0) on aircraft platforms. The same instrument can be reconfigured to operate with presampling on denuders for the sampling of RGM. It will be possible to significantly reduce sampling time compared with current approaches and offer the possibility of temporal resolution necessary to obtain well resolved diurnal profiles of RGM. It also shows promise for the speciation of RGM using programmable thermal decomposition/desorption from denuders. This instrumentation will be used primarily for research and research training but it will be integrated into educational activities and it will improve exposure to, and increase access and use of, state-of-the-art laser systems by scientists, graduate and undergraduate students at the University of Miami. The ability to accurately measure the chemical speciation and deposition rates of elemental and reactive gaseous mercury has major implications for regulatory policy and the implementation of the U.S. Clean Air Mercury Rule.