Ricerc@Sapienza

Adsorption and detection of environmental total gaseous mercury (TGM) was studied by using gold nanoparticles (AuNPs) on purpose functionalized with dithiol ligands, i.e. Biphenyl-4,4′-dithiol (BI) or p-Terphenyl-4,4′′-dithiol (TR), suitable for nanoparticles based network formation. AuNPs-BI and AuNPs-TR with size 6-8 nm were deposited onto quartz fibres and used as adsorbent materials for the detection of TGM, both indoor for adsorption studies, at defined concentrations (~4.5 ng m-3 Hg), and outdoor, at the vapour mercury concentration of the environmental countryside (~1.5 ng m-3 Hg). The role of relative humidity (RH) in the absorption process has been observed. A high Hg adsorption capability, also when exposed to sub ppb concentration, has been observed. A cold vapour atomic fluorescence spectroscopy (CVAFS) detector was used to determine gaseous mercury concentrations lower than 2 ng m-3, with a robust and reproducible procedure. Moreover, the use of quartz fibres substrate covered with AuNPs-BI or AuNPs-TR, and used for more than thirty times during the experiments, makes them competitive in the use in large-scale measurement campaigns.