Abstract: Mercury speciation in sold environmental samples using direct thermal evaporation as a perspective separation approach O. Shuvaeva1, D. Troitskii1, I. Bekesha2 1Address-1: 3, Academician Lavrent’ev prospect, Novosibirsk, 630090, Russia 2Address-2: 43, Baltiyskaya street, Primorsky Krai, Vladivostok, 690041, Russia E-mail corresponding author: olga@niic.nsc.ru Mercury is a very common and withal the most dangerous pollutant in the environment with a tendency to transform into the toxic compounds. Currently, many territories on the Earth arose as a result of the mining activity, which are prone to dispersion with the formation of fairly vast areas contaminated with mercury species, differing in mobility, bioavailability and toxicity. It is obvious that knowledge about the content of chemical forms of an element in natural environments allows us to judge the degree of danger it poses to living organisms and is therefore absolutely necessary for the preservation and even salvation of our planet. From the point of view of the possibilities of analysis at the level of chemical forms the solid samples are the most problematic objects due to the need for preliminary extraction of analytes into solution. In general it doesn’t mean the release of a specific mercury compounds from the object under study, since does not exclude the simultaneous extraction of different ones into the same fraction, as well as its incomplete release. However, liberation of mercury species directly from a solid sample can be carried out by their successive evaporation from the sample followed by isolation in accordance with their physicochemical parameters. The most promising approach for this purpose is a combination of thermal release as separation way with electrothermal atomic absorption spectrometry (TR-ETA-AAS). Despite the fact that a number of published articles are focused on the application of this approach, the question concerning the possibility of mercury speciation in real environmental and man-made samples at their co-presence remains open. Obviously, that if thermal release is used as a method for mercury species separating it requires a detailed study of their behavior under thermal exposure as noted in [1], where a programmable heating mode was proposed and applied which ensures a baseline separation of mercury(II), methylmercury chlorides, mercury sulfide and sulfate in their joint presence. A well know commercial mercury analyzer RA-915+ with RP-91C attachment (Lumex Instruments, Russia) was used being modified through the introducing into the scheme the home-made quartz furnace to provide a separation of the zones for the analytes continuous release under heating in the argon atmosphere using temperature control directly in the sample, and ETA-AAS-detection . Herewith the problem of eliminating the influence of the matrix was overcome by dilution of the sample with an inert blunt material that does not react with the analytes. The developed method allows determination of mercury(II) chloride, methylmercury chloride, mercury sulfide and sulphate at the level of 0.3, 0.05, 0.03 and 0.20 μg (as mercury) with a reproducibility of 20, 15, 10 and 25%, respectively. The accuracy of the proposed assay has been confirmed using certified reference material ERM CE464 as well as added-found method. [1] O. Shuvaeva, D. Troitskii, I. Bekesha, P. Plusnin, AnalMethods, 15(2023) 937-943.

Cite: Shuvaeva O. , Troitskii D. , Bekesha I.
Mercury speciation in sold environmental samples using direct thermal evaporation as a perspective separation approach
14th International Conference on Instrumental Methods of Analysis: Modern Trends and Applications 14-17 Sep 2025