Mercury volatile species analysis

Main mercury species in ambient air are elemental mercury (Hg°), reactive gaseous mercury (Hg(II)), mercury bound to aerosols, and methylmercury. Though dimethyl-mercury is together with Hg° the most volatile form of Hg, it has not been detected unequivocally in the atmosphere. Elemental mercury represents >95% of Hg in the atmosphere with ambient concentrations at the order of 1-5 ng m whereas MeHg in air was found to be in the range of 1 to 20 pg m (Pirrone et al. 2001). For this reason, in most cases mercury is pre-con-centrated on solid absorbers (gold, silver, activated carbon traps, etc.) prior to analysis (Drabaeck and Iverfeldt 1992, Horvat 1996). 

The gas phase interferences are obviously limited to those species which can be transferred into the vapor phase under these conditions, i.e., the hydride-forming elements and mercury. And if tin(II) chloride is used for the determination of mercury, no other element is volatilized so that no such interferences can occur. The mumal interferences of hydride-forming elements, however, may be quite severe, particularly in batch systems [36]. FI systems have been shown one more time to be superior also in this case as these mutual interferences are one to two orders of magnitude less pronounced compared to batch systems [37]. They should therefore be no problem in the analysis of body fluids or tissues, even in the case of a severe intoxication. 

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