Analytical Sciences

Abstract − Analytical Sciences, 26(6), 681 (2010).

Determination of Iron Monosulfide and Iron Disulfide in Suspensions by an Electrochemical Method Using a Platinum-Silver Twin-Electrode
Xiaojun DIAO and Katsuhiro SUMI
Department of Environmental Systems Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi 782-8502, Japan
New electrochemical technique with a Pt-Ag twin electrode is proposed for the determining the contents of iron sulfides (FeS and FeS2) in a suspension. After electrolytic oxidation with a Pt electrode, Fe2+ was measured by linear sweep voltammetry. From relations of the charge amount from the baseline to the peak in the voltammogram of Fe2+ with the content of FeS or FeS2, linear calibration curves (a) and (b) were prepared, respectively. After measurements of Fe2+, Fe2+ and S0 were reduced with a Pt electrode to remove Fe2+ and to produce S2−. With an Ag electrode, Ag2S was deposited on Ag. A linear curve (c) was prepared from a relation between the charge amount of the Ag2S peak part and the FeS content. However, in the suspension of FeS2, Ag2S can not be detected. When this method is applied to a mixed suspension of FeS and FeS2, the content of FeS can be determined with curve (c), whereas curves (a) and (b) were not effective in the mixed suspension.