University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Geological -> rock -> apatite

Citations 2

"Determination Of The Sum Of Rare-earth Elements By Flow Injection Analysis With Arsenazo III, 4-(2-pyridylazo) Resorcinol, Chrome Azurol S And 5-bromo-2-(2-pyridylazo) 5-diethylaminophenol Spectrophotometric Reagents"
Talanta 1988 Volume 35, Issue 4 Pages 259-265
D. B. Gladilovich, V. Kubán and L. Sommer

Abstract: The interactions of La(III) with the four cited spectrophotometric reagents were studied in both stationary and flow systems. In the stationary systems pH and unconsumed reagent most affected sensitivity; the most sensitive reagents were Chrome Azurol S [I (C. I. Mordant Blue 29), with cationic surfactant] and 4-(2-pyridylazo)resorcinol(II). Rare-earth chelates with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol decomposed in alkaline medium, making it an unsuitable reagent. Arsenazo III produced the lowest absorbances, but gave the best detection limits for Eu and Dy when the method was extended to all rare-earth metals. In flow systems only arsenazo III proved suitable for determining the sum of rare-earth elements if light rare earths occurred in the sample. Results are also given for spectrophotometric determination of La, Ce and Nd with I plus cationic surfactant and II. The flow injection method was applied in the analysis of oxide concentrates and apatites with good results.
Metals, rare earth Cerium Dysprosium Europium Lanthanum Metals, lanthanides Neodymium Spectrophotometry Chelation

"Determination Of Rare-earth Elements By Ion Pair HPLC With Post-column Derivatization Using Arsenazo III"
Collect. Czech. Chem. Commun. 1988 Volume 53, Issue 8 Pages 1664-1677
Kuban, V.;Gladilovich, D.B.

Abstract: A portion (10 to 25 µL) of sample solution (prep. described) was analyzed on a column (15 cm x 3 mm) of Separon SGX C18 (5 µm) modified with sorbed ammonium dodecyl sulfate, protected by a column (5 cm x 3 mm) of Separon SGX C18 (5 µm) or Silperl silica gel (14 µm) with a mobile phase (1 mL min-1) of 20 to 160 mM ammonium DL-2-hydroxy-2-methylpropionate(I) solution (pH 4.5). Post-column derivatization was achieved with 5 µM-arsenazo III in 0.1 M formate buffer (pH 2.9 to 3.0); detection was at 660 nm. With isocratic elution, calibration graphs (peak height vs. concentration.) were rectilinear from 10 to 150 ng of rare-earth metal in 10 or 25 µL injected. With stepwise gradient elution with 40 mM I for 5 min, 80 mM I for the next 10 min and 160 mM I after 15 min, the calibration graphs were rectilinear from 6 to 155 ng of rare-earth metal in 10 or 25 µL injected. The method was applied in the determination of rare-earth metals in apatite, oxide concentrates, and a phosphor. Results agreed well with those obtained by optical methods.
Metals, rare earth HPLC Spectrophotometry Method comparison Post-column derivatization