Stable Isotope Ratios of Mercury in Commercially Available Thermometers and Fluorescent Tubes

Five stable isotope ratios of mercury (Hg-199/Hg-198, Hg-200/Hg-198, Hg-201/Hg-198, Hg-202/Hg-198, and Hg-204/Hg-198) in commercially available thermometers and fluorescent tubes were analyzed to characterize their potential anthropogenic emission source to landfills, manufacturing factories, and our daily lives. The results for the liquid metal mercury yielded from the thermometers showed similar mass-independent fractionation values to those in the literature. The analysis of fluorescent tubes resulted in that more than 96% of mercury in the fluorescent tubes was found in the adsorbed state, and up to 3.5% of mercury was in the gas-phase. Unique mass-independent isotope fractionation values were found in the gaseous and adsorbed mercury in the fluorescent tubes. This fractionation is distinct from other emission sources and systematic; therefore, it can potentially be used to fingerprint mercury in fluorescent tubes in environmental samples.