Development of a fieldable real-time mercuric chloride monitor using laser photofragment emission

FUEL 17

Thomas A. Reichardt, tareich@sandia.gov1, Jeffrey M. Headrick, jmheadr@sandia.gov1, Alexandra A. Hoops, aahoops@sandia.gov1, Jude A. Kelley, jkelley@holycross.edu2, Jeffrey P. Koplow, jkoplow@sandia.gov1, Sean W. Moore, seamoor@sandia.gov1, and Dahv A. V. Kliner, dakline@sandia.gov1. (1) Remote Sensing and Energetic Materials, Sandia National Laboratories, P. O. Box 969, MS 9056, Livermore, CA 94551, (2) Chemistry Department, College of the Holy Cross, Haberlin Hall, Rm. 117, Worcester, MA 01610
We have constructed a breadboard instrument capable of detecting ppb levels of HgCl2 by photofragment emission (PFE) using a near-infrared pulsed fiber amplifier that is frequency converted to the ultraviolet. Excitation of the HgCl2 11P u ¬ 11Sg+ transition at 213 nm yields 253.7-nm emission that is proportional to the HgCl2 concentration. We have previously characterized and quantified the HgCl2 PFE method by evaluating the potential impact of interference gases, determining the dependence of the PFE signal on laser irradiance, and examining the effects of collisional quenching by major flue-gas constituents N2, O2, and CO2. In this paper we describe the system architecture of this instrument, including the compact laser source, beam-formatting optics, photodetector, signal-conditioning electronics, and on-board system performance diagnostics. Initial testing of the instrument is also summarized.
 

Mercury and Other Trace Elements in Fuel: Emissions and Control
8:25 AM-11:35 AM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 240/241, Oral

Division of Fuel Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008