Voltammetric Determination of Low-Molecular-Weight Sulfur Compounds in Hydrothermal Vent Fluids - Studies with Hydrogen Sulfide, Methanethiol, Ethanethiol and Propanethiol

Determination of sulfide compounds in hydrothermal vent fluid samples was performed by DPCSV. The methodology was applied to speciate sulfides via primitive and first-derivative curve interpretation. Hydrogen sulfide, methanethiol, and propanethiol were simultaneously assayed in samples containing no ethanethiol. In the presence of ethanethiol, the organic sulfides were determined without speciation. Sulfides were determined in an acidic electrolyte, and detection limits ranging from 0.1 to 1.1 mu mol L-1 were calculated. The method was tested in real hydrothermal vent fluid samples, with recoveries ranging from 86.9% (R-SH) to 115.3% (H2S). Interference of the metallic species present in seawater was investigated.