Geochemical data indicate that protons released during pyrite (FeS2) oxidation are important drivers of mineral weathering in oxic and anoxic zones of many aquatic environments, including those beneath glaciers. Oxidation of FeS2 under oxic, circumneutral conditions proceeds through the metastable intermediate thiosulfate (S2O3 (2-)), which represents an electron donor capable of supporting mic...

The intermediates ISO3 (m/z = 207) and IS2O3 (m/z = 239) generated in aqueous (NaI/Na2S2O3) microdroplets traversing dilute O3 gas plumes are detected via online electrospray mass spectrometry within ~ 1 ms, and their stabilities gauged by collisionally induced dissociation. The simultaneous detection of anionic reactants and the S2O6, HSO4, IO3, and I3 products, as a function of experimental c...

As a sensitive and selective analytical technique, gold nanoparticles-based colorimetric sensing was characterized by its simplicity and cost-effectiveness. Specific methods have been extensively developed for different targets in diverse samples. In this study, a label-free method for sensing Co in aqueous solutions was described. The target was achieved by the induced aggregation of thiosulfa...

Oxidation of pyrite in aqueous solutions in contact with air (oxygen 20%) was studied at 25°C using short-term batch experiments. Fe and SO4 2 were the only dissolved Fe and S species detected in these solutions. After a short period, R [S]tot/[Fe]tot stabilized from 1.25 at pH 1.5 to 1.6 at pH 3. These R values were found to be consistent with previously published measurements (as calculated f...

A pre-oxidation procedure which converts arsenite [As(III)] into arsenate [As(v)] was investigated in urinary arsenic speciation prior to on-line photo-oxidation hydride generation with ICP-MS detection. This sample pre-oxidation method eliminates As(III) and As(v) preservation concerns and simplifies the chromatographic separation. Four oxidants, Cl2, MnO2, H2O2 and I3-, were investigated. Chl...

In this work, we developed a novel, label-free, colorimetric sensor for Pb(2+) detection based on the acceleration of gold leaching by graphene oxide (GO) at room temperature. Gold nanoparticles (AuNPs) can be dissolved in a thiosulfate (S2O3(2-)) aqueous environment in the presence of oxygen; however, the leaching rate is very slow due to the high activation energy (27.99 kJ mol(-1)). In order...

Investigations were carried out on the carbon-dots (C-dots) based fluorescent off - on (Fe(3 + )- S2O3(2-)) and on - off (Zn(2 + )- PO4(3-)) sensors for the detection of metal ions and anions. The sensor system exhibits excellent selectivity and sensitivity towards the detection of biologically important Fe(3 + ), Zn(2 + ) metal ions and S2O3(2-), PO4(3-) anions. It was found that the functiona...