You are here:
IMPINGER SOLUTIONS FOR THE EFFICIENT CAPTURE OF GASEOUS MERCURY SPECIES USING DIRECT INJECTION NEBULIZATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (DIN-ICP/MS) ANALYSIS
Citation:
Hedrick, E J., H. Minges, T. G. Lee, AND P. Biswas. IMPINGER SOLUTIONS FOR THE EFFICIENT CAPTURE OF GASEOUS MERCURY SPECIES USING DIRECT INJECTION NEBULIZATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (DIN-ICP/MS) ANALYSIS. Presented at Air and Waste Management Association Meeting, Salt Lake City, UT, June 18-21, 2000.
Description:
Currently there are no EPA reference sampling mehtods that have been promulgated for measuring Hg from coal combustion sources. EPA Method 29 is most commonly applied. The ASTM Ontario Hydro Draft Method for measuring oxidized, elemental, particulate-bound and total Hg is now undergoing evaluation and review. Both these methods employ acidic permanganate impingers to capture elemental Hg and use cold vapor atomic absorption spectrometry for analysis (CVAA). Elemental Hg is oxidized in the permanganate solution and reduced back to elemental Hg for CVAA analysis. Accurate estimates of total Hg emissions depends entirely on the efficiency of the impingers to oxidize, capture and stabilize Hg in solution. In this work inductively coupled plasma mass spectrometry (ICP/MS) using direct injection nebulization (DIN) is used to evaluate novel impinger solution compositions that more efficiently capture elemental and oxidized Hg. The work presented will describe analytical capabilities, experimental set-up and results from impinger solution experiments. Results from a thorough investigation of the application of DIN-ICP/MS for routinely measuring total Hg in a variety of solution matirces will be presented as well as a comparison to CVAA. Various impinger solution compositions to selectively capture Hg species were efaluated by generating elemental Hg vapor and HgCl2, entraining the gases in a stream of air and measuring how much Hg could be captured in the impinger solutions. DIN-ICP/MS allowed for the evaluation of solutions not amenable to CVAA. Evidence will be presented that indicates the acidified permanganate solution employed in EPA Method 29 and the Ontario Hydro Method may not capture Hg very efficiently. Implications for accurately measuring Hg in coal combustion emissions will be presented.