4F - Hg - Cold Vapour FIMS

0.5 g sample is digested with aqua regia to leach out soluble compounds. The Hg in the resulting solution is oxidized to the stable divalent form . An aliquot of the digestion solution is mixed with a potassium permanganate solution. Using the flow injection cold vapor mercury technique, Hg (II) is reduced to mercury vapour using stannous chloride, argon is bubbled through the mixture of sample, carrier, and reductant solutions in a closed reaction system to liberate and transport the Hg atoms into an absorption cell. Hg is determined via the absorption of light at 253.7 nm. The maximum amount absorbed (peak height) is directly proportional to the concentration of mercury atoms in the light path. The sensitivity of the cold vapor technique is far greater than can be achieved by conventional flame AA. A Perkins Elmer FIMS 100 is used for the analysis.