Titrimetric, coulometric and spectrophotometric determination of manganese following perchloric acid oxidation in the presence of pyrophosphate.
Manganese is oxidized quantitatively to a violet, tervalent pyrophosphate in a boiling mixture of equal parts of perchloric acid and phosphoric add. This Mn(III) can be titrated potentiometrically or coulometrically with iron(II); it can also be measured spectrophotometrically. If the titrimetric method is carried out with titanium (III) or chromium(II), iron can also be titrated immediately after the manganese. The methods were applied to a new reference sample, ISU 600 Manganiferous Iron Ore, and to manganese ore, spiegeleisen, ferromanganese, and rail steel. Manganese(II) oxalate dihydrate has been reinvestigated as a primary standard and is highly recommended.
Knoech
J
J
Department of Chemistry, Iowa State University, Ames, Iowa, U.S.A.
Diehl
H
H