| Summary: | 碩士 === 國立交通大學 === 應用化學系分子科學碩博士班 === 100 === We applied differential pulse voltammetry (DPV) to detect ethanethiol in this study. Catechol, added to the sample solution, was readily oxidized to form o-benzoquinone during the oxidation cycle. Ethanethiol then reacted with o-benzoquinone immediately to form a catechol-thiol adduct which was further oxidized during the same cycle. The oxidation potential of the adduct was found ~0.5 V lower than that of ethanethiol. Quantitative analysis was investigated using the DPV oxidation current. A linear dynamic range of 0.65 uM–59.3 uM (ethanethiol solution prepared in butanol) was obtained while the detection limit was 0.068 uM (S/N = 3). Interferences including dimethyl sulfide, hydrogen sulfide, sulfur dioxide, styrene, acetaldehyde, and nitrogen dioxide were doped in the butanol sample solutions in selectivity tests. Hydrogen sulfide created major problem due to its very close oxidation potential to ethanethiol. Detection of gaseous ethanethiol was also examined under the ambient environment. When gas volume of 100 L was collected in neat butanol, the detectable range of ethanethiol was found 0.4–37 mg/m3. This technique conformed to the regulation set by the Environmental Protection Agency.
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