CHELOMETRIC TITRATIONS USING AN AZOARSONIC ACID INDICATOR

Journal Article · Sun Jun 01 00:00:00 EDT 1958 · Analytical Chemistry (U.S.) Formerly Ind. Eng. Chem., Anal. Ed.

DOI:https://doi.org/10.1021/ac60138a032· OSTI ID:4338224

Fritz, J S; Oliver, R T; Pietrzyk, D J

Arsenazo STA3-(2-arsonophenylazo)-4,5-dihydroxy-2,7naphthalenedisulfonic acid, trisodium salt! is an excellent indicator for the EDTA titration of rare earths and yttrium in weakly acid solution. In many cases, use of masking agents or a simple preliminary separation permits determination of rare earths in samples containing foreign metal ions. Aluminum is masked by sulfosalicylate, and interference from calcium and magnesium is avoided by proper pH control. Small amounts of uranium, iron, and most divalent metals are masked by diethyldithiocarbomate; larger amounts of these metals are removed by exraction of their diethyldithiocarbamate complexes. Thorium interferes with the titration of rare earths, but can be titrated at a more acidic pH. Titration of thorium in the presence of uranium is possible. (auth)

• Research Organization: Iowa State Coll., Ames
• Sponsoring Organization: USDOE
• NSA Number: NSA-12-009703
• OSTI ID: 4338224
• 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: 30; ISSN ANCHA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDITY
ALUMINUM
ARSENAZO
ARSENIC COMPOUNDS
CALCIUM
CHEMISTRY
COMPLEXES
EDTA
IMPURITIES
IONS
IRON
MAGNESIUM
METALS
ORGANIC ACIDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
QUALITATIVE ANALYSIS
QUANTITY RATIO
RARE EARTHS
SALICYLIC ACID
SALTS
SEPARATION PROCESSES
SOLUTIONS
SULFONIC ACIDS
THORIUM
URANIUM
YTTRIUM