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Author Apple, R. F. ♦ Zittel, H. E.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ AMPEROMETRY ♦ CHROMIUM ♦ ELECTRIC POTENTIAL ♦ ELECTRODES ♦ ERRORS ♦ FLUORIDES ♦ GRAPHITE ♦ INTERFERING ELEMENTS ♦ IRON SULFATES ♦ MINERAL ACIDS ♦ MIXING ♦ OXIDATION ♦ POLAROGRAPHY ♦ QUALITATIVE ANALYSIS ♦ QUANTITATIVE ANALYSIS ♦ SILVER OXIDES ♦ SOLUTIONS ♦ TITRATION
Abstract A rapid and precise method for the amperometric titratlon of chromium in mixtures of fluoride salts was developed. The salt is dissolved in a mineral acid mixture, after which the chromium is oxidized to Cr(VI) with argentic oxide. The Cr(VI) is then amperometrically titrated with ferrous sulfate. This reduction causes no change in cell current urtil the end point is reached where the current decreases. The titration is followed by means of a polarograph equipped with a titration cell that consists of a pyrolytic graphite electrode vs the S.C.E. The optimum potential for the titration is + 1.0 volt vs the S.C.E. In the range of 1 to 50 mu g of Cr(VI) titrated, the relative standard deviation is less than 2%. Of the interferences studied, only Mn(VII) and Ce(IV) interfere with the method at the level of concentrations studied. (auth)
ISSN 00032700
Educational Use Research
Learning Resource Type Article
Publisher Date 1964-05-01
Publisher Department Oak Ridge National Lab., Tenn.
Journal Analytical Chemistry
Volume Number 36
Organization Oak Ridge National Lab., Tenn.


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