IRON(II) AS AN INDICATOR ION FOR AMPEROMETRIC TITRATIONS WITH (ETHYLENEDINITRILO) TETRAACETIC ACID. APPLICATION TO THE DETERMINATION OF THORIUM
A method for amperometric titrations with EDTA in which Fe/sup 2+/ is used as an indicator is described. A potential of +0.4 volt vs the S.C.E. is applied to a platinum electrode. At this potential Fe/sup 2+/ is not oxidized; however, FeY/sup 2-/, which is formed after the titratron is complete, is oxidized, and the excess titrant is indicated by a linear increase in current. Most titrations are carried out in an acetate buffered medium at pH 4.5. This method is applicable to the determination of elements that form EDTA chelates with a stability constant of 10/sup 17/ or greater with several exceptions. Thorium(IV) in the presence of U/sup 6+/, Zr, and other cations was determined with a relative standard deviation of about 2%. Sulfate and small amounts of fluoride do not interfere. (auth)
- Research Organization:
- Oak Ridge National Lab., Tenn.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-16-011537
- OSTI ID:
- 4800972
- Journal Information:
- Analytical Chemistry (U.S.) Formerly Ind. Eng. Chem., Anal. Ed., Journal Name: Analytical Chemistry (U.S.) Formerly Ind. Eng. Chem., Anal. Ed. Vol. Vol: 34; ISSN ANCHA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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