Permanganate trapping/ digestion solutions are frequently used for Hg extraction from solid matrices. Biswas et al. (2008) use a KMnO4/H2SO4 solution to trap gaseous Hg after double-tube furnace combustion of solids. Sun et al. (2013) show that aqua regia (HNO3/HCl) is equally efficient. BrCl is a widely used oxidizing reagent in Hg analytical chemistry. Issaro et al. (2009) reviewed chemical reagents used for mercury extraction. Different methods are hard to compare because of the wide range of mixtures and concentrations. I am wondering which is the most oxidizing solution and best for Hg trapping/extraction and the chemistry that lies behind.

References

Biswas A, Blum JD, Bergquist BA, Keeler GJ, Xie ZQ. Natural Mercury Isotope Variation in Coal Deposits and Organic Soils. Environmental Science & Technology 2008, 42(22): 8303-8309.

Sun R, Enrico M, Heimbürger L-E, Scott C, Sonke J. A double-stage tube furnace—acid-trapping protocol for the pre-concentration of mercury from solid samples for isotopic analysis. Analytical and Bioanalytical Chemistry 2013: 1-11.

Issaro N, Abi-Ghanem C, Bermond A. Fractionation studies of mercury in soils and sediments: A review of the chemical reagents used for mercury extraction. Analytica Chimica Acta 2009, 631(1): 1-12.