Determination of Iron Monosulfide and Iron Disulfide in Suspensions by an Electrochemical Method Using a Platinum-Silver Twin-Electrode

摘要

New electrochemical technique with a Pt-Ag twin electrode is proposed for the determining the contents of iron sulfides (FeS and FeS_(2)) in a suspension. After electrolytic oxidation with a Pt electrode, Fe~(2+) was measured by linear sweep voltammetry. From relations of the charge amount from the baseline to the peak in the voltammogram of Fe~(2+) with the content of FeS or FeS_(2), linear calibration curves (a) and (b) were prepared, respectively. After measurements of Fe~(2+), Fe~(2+) and S~(0) were reduced with a Pt electrode to remove Fe~(2+) and to produce S~(2?). With an Ag electrode, Ag_(2)S was deposited on Ag. A linear curve (c) was prepared from a relation between the charge amount of the Ag_(2)S peak part and the FeS content. However, in the suspension of FeS_(2), Ag_(2)S can not be detected. When this method is applied to a mixed suspension of FeS and FeS_(2), the content of FeS can be determined with curve (c), whereas curves (a) and (b) were not effective in the mixed suspension.