METAL-INDICATOR SYSTEMS IN (ETHYLENE-DINITRILO) TETRAACETIC ACID TITRATIONS

Technical Report · Sun Dec 01 04:00:00 EST 1957

OSTI ID:4293998

Lane, W J; Fritz, J S

Three organic reagents were stadied and applied to titrations with (ethylenediniirilo) tetraacetic acid. The techniques of photometric titrations annd precision spectrophotomctry have been applied to titrations of rare earths as dilute as 10/sup -6/ M. These reagents are 7(1-naphthylazo)-5-sulfo-8- hydroxyquinoline or Naphthyl Azoxine, 2-(2-hydroxy-3,6-disulfo-1- naphthylazo)benzene-arsonic acid or Thorin annd 2-(1,8-dihydroxy3 6-disulfo-2- naphthylazo)-benzenearsonic acid or Arsenazo. Naphthyl Azoxine was used as the indicator for direct EDTA titrations of some transition metals, rare earths and thorium. The interference of urannium was masked by tartrate ion in the titration of the transition metals but not rare earths annd thorium. The copper- Naphthyl Azoxine complex was characterized as a 1:2 complex with a formation constant of l.9 x l0/sup 15/ at pH 6. Thorin was used as the indicator ior indirect titrations of rare earths, several metals and fluoride ion. Lanthanum was used as the titrant of the excess EDTA. Arsenazo was used as the indicator for the direct EDTA photometric titration of thc rare earths. Titrations of as little as 10 mu g of rare earth were performed with an error only 2%. A tenfold excess of uranium was successfully masked in these titrations. The lanthanum-Arscnazo complex was characterized as a 1:1 complex with a formation constant of 2.7 x l0/sup 8/ at pH7. (auth)

• Research Organization: Ames Lab., Ames, Iowa
• DOE Contract Number: W-7405-ENG-82
• NSA Number: NSA-13-002721
• OSTI ID: 4293998
• Report Number(s): ISC-945
• Country of Publication: United States
• Language: English

Related Subjects

ABSORPTION
ACIDITY
ARSENAZO
ARSENIC COMPOUNDS
CHEMICALS
CHEMISTRY
COLOR
COMPLEXES
COMPOUNDS
COPPER COMPOUNDS
EDTA
ERRORS
FLUORIDES
HYDROXIDES
INTERFERING ELEMENTS
IONS
LANTHANUM COMPOUNDS
MEASURED VALUES
NAPHTHALENE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHENYL RADICALS
PHOTOMETRY
QUALITATIVE ANALYSIS
QUANTITY RATIO
RARE EARTHS
SENSITIVITY
SPECTROSCOPY
TARTARIC ACID
THORIN
THORIUM
TITRATION
TRACE AMOUNTS
TRANSITION METALS
URANIUM