The development of iodine based impinger solutions for the efficient capture of Hg-0 using direct injection nebulization - Inductively coupled plasmamass spectrometry analysis
E. Hedrick et al., The development of iodine based impinger solutions for the efficient capture of Hg-0 using direct injection nebulization - Inductively coupled plasmamass spectrometry analysis, ENV SCI TEC, 35(18), 2001, pp. 3764-3773
Citations number
30
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection
nebulization (DIN) was used to evaluate novel impinger solution compositio
ns capable of capturing elemental mercury (H-g(0)) in EPA Method 5 type sam
pling. An iodine based impinger solution proved to be very efficient for H-
g(0) capture and was amenable to direct analysis by DIN-ICP/MS. H-g(0) capt
ure efficiency using aqueous iodine (I-3(-)) was comparable to H-g(0) captu
re using acidified potassium permanganate impinger solutions which were ana
lyzed by cold vapor atomic absorption spectrometry (CVAAS), with greater th
an 98% capture of H-g(0) in the first oxidizing impinger. Using DIN-ICP/MS,
it was demonstrated for the first time that iodine can be generated just p
rior to impinger sampling for efficiently oxidizing H-g(0) and retaining it
in solution as HgI42-. Due to the increased interest in Hg speciation from
combustion sources and the potential for using DIN-ICP/MS for multiple met
als analyses, an impinger sampling train for gaseous Hg speciation and mult
iple metals analyses using DIN-ICP/MS analyses is presented. The unique fea
ture 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 combust
ed in a bench scale coal system, and gaseous Hg species (oxidized and eleme
ntal) were determined using the proposed impinger train. The DIN-ICP/MS ins
trumental detection limit was 0.003 ppb, and MDLs ranged from 0.007 to 0.11
6 mug/L (ppb) in a variety of impinger solutions used for Hg capture.