| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1337283 | Polyhedron | 2012 | 5 Pages |
The construction and general performance characteristics of a novel potentiometric electrode responsives to hydrogen (lyonium/lyate) ions are described. This sensor is based on the use of the magnetite mineral as the working surface of the electrode. The sensor exhibits fast, stable and sub-Nernstian for the p-toluenesulphonic acid over the concentration range 1 × 10−1 to 1 × 10−3 M at 25 °C with slope of 39.3 ± 0.6 and 41.0 ± 0.5 per concentration decade in propylene carbonate and γ-butyrolactone, respectively. The response time is 13 and 15 s in the same order in both solvents. The change in the electrode potential from the acidic to basic region was 375 to −75 mV in γ-butyrolactone and 394 to 6 mV in propylene carbonate. The determination of 25–30 mg of some important organic acids (benzoic, anthranilic, and salicylic acid) in non-aqueous media shows an average recovery of 100.2% and 99.8% with relative standard deviation of 0.17–0.47% in both solvents. Potentiometric titrations of acids involving potassium hydroxide as titrant are monitored in both solvents with inflection point from 207 to 109 mV.
Graphical abstractCyclic voltammetry was applied for the magnetite mineral characterization in non-aqueous solution. The magnetite mineral as a new indicator electrode for the potentiometric titrations of acids and bases in γ-butyrolactone and propylene carbonate was studied. This electrode exhibited useful features with respect to its mechanical resistance, very low cost, simple preparation, great hardiness and chemical inertness to the working mediums.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The magnetite mineral characterization in non-aqueous solution using carbon paste. ► Study of the electroanalytical characteristics of the magnetite indicator electrode. ► Application of the magnetite indicator electrode for acid–base titration.
