Study of the chromogenic reactions of semi-xylenol orange with rare earths and thorium

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Analytical Letters; (United States)

DOI:https://doi.org/10.1080/00032719208018250· OSTI ID:7046794

Hafez, M A.H. ^[1]

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1. El-Mansoura Univ. (Egypt)

The composition, stability constants and molar absorption coefficients of the chelates of thulium, ytterbium, lutetium and thorium ions with Semi-xylenol Orange (SXO) are determined spectrophotometrically in a medium of hexamine, and chloroacetate buffer. In the thulium, ytterbium, lutetium and thorium-Semi-xylenol Orange systems, Tm(SXO), Yb(SXO), Lu(SXO) and Th(SXO) chelates are formed with logarithmic overall stability constants of 12.48 {plus minus} 0.01, 12.55 {plus minus} 0.01, 12.94 {plus minus} 0.015 and 22.16 {plus minus} 0.01 and molar absorption coefficients of 2.22 {times} 10{sup 4} (530 nm), 2.17 {times} 10{sup 4} (532 nm), 2.25 {times} 10{sup 4} (530 nm) and 3.33 {times} 10{sup 4} (535 nm) dm{sup 3} mol{sup {minus}1} cm{sup {minus}1} respectively. The precision and accuracy attainable in direct spectrophotometric titrations of the Tm{sup 3+}, Tb{sup 3+}, Lu{sup 3+} and Th{sup 4+} separately and the successive determination of each of the three rare earths and Th{sup 4+} ion with a 0.001 mol dm{sup {minus}3} solutions of diethylenetriaminepentaacetic acid (DTPA) and PbCl{sub 2} of the same concentration using Semi-xylenol Orange (SXO) as a metallochromic indicator have been studied. Spectrophotometric determination of Tm{sup 3+}, Tb{sup 3+}, Lu{sup 3+} and Th{sup 4+} individually using SXO at the optimum conditions of maximum color development have been carried out. Thorium has been determined spectrophotometrically in three different artificial samples with lutetium similar to those of monazite mineral. Ytterbium (III) has been determined in three different laboratory synthesized samples with Ca{sup 2+} and Fe{sup 3+} similar to those of euxenite mineral which occurs in nature and the results were reproducible and satisfactory.

• OSTI ID: 7046794
• Journal Information: Analytical Letters; (United States), Journal Name: Analytical Letters; (United States) Vol. 25:9; ISSN ANALB; ISSN 0003-2719
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ACTINIDE COMPLEXES
ACTINIDES
CATIONS
CHARGED PARTICLES
CHELATES
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
COMPLEXES
DATA
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
IONS
LUTETIUM
LUTETIUM COMPLEXES
METALS
NUMERICAL DATA
QUANTITATIVE CHEMICAL ANALYSIS
RARE EARTH COMPLEXES
RARE EARTHS
SPECTROSCOPY
THORIUM
THORIUM COMPLEXES
THULIUM
THULIUM COMPLEXES
TITRATION
YTTERBIUM
YTTERBIUM COMPLEXES