title: The development of iodine based impinger solutions for the efficient capture of Hg0 using direct injection nebulization-inductively coupled plasma mass spectrometry analysis.
abstract: Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hg0) in EPA Method 5 type sampling. An iodine based impinger solution proved to be very efficient for Hg0 capture and was amenable to direct analysis by DIN-ICP/MS. Hg0 capture efficiency using aqueous iodine (I3-) was comparable to Hg0 capture using acidified potassium permanganate impinger solutions which were analyzed by cold vapor atomic absorption spectrometry (CVAAS), with greater than 98% capture of Hg0 in the first oxidizing impinger. Using DIN-ICP/MS, it was demonstrated for the first time that iodine can be generated just prior to impinger sampling for efficiently oxidizing Hg0 and retaining it in solution as HgI4(2-). Due to the increased interest in Hg speciation from combustion sources and the potential for using DIN-ICP/MS for multiple metals analyses, an impinger sampling train for gaseous Hg speciation and multiple metals analyses using DIN-ICP/MS analyses is presented. The unique feature of such a sampling train is that each impinger solution in the series is amenable to direct analysis by DIN-ICP/MS. A bituminous coal was combusted in a bench scale coal system, and gaseous Hg species (oxidized and elemental) were determined using the proposed impinger train. The DIN-ICP/MS instrumental detection limit was 0.003 ppb, and MDLs ranged from 0.007 to 0.116 microg/L (ppb) in a variety of impinger solutions used for Hg capture.
authors.affiliation: National Exposure Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, USA. hedrick.elizabeth@epa.gov
authors.forename: E
authors.initials: E
authors.lastname: Hedrick
authors.forename: T G
authors.initials: TG
authors.lastname: Lee
authors.forename: P
authors.initials: P
authors.lastname: Biswas
authors.forename: Y
authors.initials: Y
authors.lastname: Zhuang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D003031:Coal; D004784:Environmental Monitoring / Q000379:methods*; D017745:Incineration; D007455:Iodine / Q000737:chemistry*; D013058:Mass Spectrometry; D008628:Mercury / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D000393:Air Pollutants; D003031:Coal; D007455:Iodine; D008628:Mercury