Mercury compounds characterization by thermal desorption

The ability to accurately determine metal mercury content and identify different mercury species in solid samples is essential for developing remediation and control strategies. The aim of the present study is to characterize mercury compounds based on thermal desorption. For this purpose a series of samples was prepared and the operational parameters—heating velocity, carrier gas—were optimized. Fifteen commercial mercury compounds were analyzed for use as fingerprints. The results of the study show that the identification of mercury species by the method of thermal desorption is possible. The temperature of desorption increased according to the following order HgI2<HgBr2<Hg2Cl2åHgCl2<Hg(CN)2<HgCl2O8·H2O<Hg(SCN)2<HgS (red)<HgF2<Hg2(NO3)2·2H2O<Hg(NO3)2·H2O<HgO (yellow, red)<Hg2SO4<HgSO4. A comparison of the estimated total mercury content with the mercury content calculated by integrating the area of the desorption curve shows that recoveries of 79–104% for HgS can be estimated. The proposed method represents a significant step forward in direct mercury analysis in solid samples.