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
Email: schalk@unf.edu
Website: @unf

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Metals, lanthanides

@ ChemSpider@ NIST@ PubChem

Citations 10

"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.
Concentrate Apatite Spectrophotometry Chelation

"Use Of Boric Acid To Improve The Microwave-assisted Dissolution Process To Determine Fluoride Forming Elements In Steels By Flow Injection Inductively Coupled Plasma Mass Spectrometry"
J. Anal. At. Spectrom. 1998 Volume 13, Issue 10 Pages 1193-1197
Aurora G. Coedo, M. Teresa Dorado, Isabel Padilla and Francisco J. Alguacil

Abstract: The applicability of FI-ICP-MS combined with microwave sample digestion for the simultaneous determination of trace amounts of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in iron and steel samples was studied. The use of hydrofluoric acid in the sample dissolution process produced nearly invisible insoluble particles with the REEs, leading to erroneous quantification of these elements. The addition of boric acid, complexing HF, solved this problem. By monitoring the transient signals produced by the FI microsampling system, it was possible to evaluate the effectiveness of the sample dissolution procedure. Severe depressive matrix effects caused by the sample matrix were encountered when the signals were compared with those from HNO3 solutions; in contrast, no effects were observed with the addition of boric acid. A highly alloyed steel, stainless steel certified reference material JK 37 (Sandvik Steel), was used to evaluate the effectiveness of the dissolution procedure and to develop the method. The limits of quantification (LOQ) calculated from 10.sqroot.s ranged between 0.008 µg g-1 for Lu and 0.040 µg g-1 for Nd. The relative standard deviation for all the analytes was better than 3% (n=4) for concentrations >10 times the LOQ.
Alloy Mass spectrometry Sample preparation Reference material Interferences

"Multicomponent Kinetic Determination Of Lanthanides With Stopped-flow, Diode Array Spectrophotometry And The Extended Kalman Filter"
Anal. Chem. 1994 Volume 66, Issue 4 Pages 458-463
Brett M. Quencer and S. R. Crouch

Abstract: Working solution of 3-30 µM-La(III), -Pr(III) and -Nd(III), singly or in combination, were mixed with an equal volume of 0.2 mM aqueous 4-(2-pyridylazo)resorcinol in a stopped-flow mixing system. Using a linear photodiode array the progress of the reaction was followed; a complete spectrum was recorded every 3.5 ms and up to 100 spectra were acquired in a single experiment. The different wavelengths (up to 4) used for each element and their differing rates of reaction permitted the analysis of the mixtures. The extended Kalman filter program was written in QuickBASIC, version 4.0, with the algorithm previously described (cf. Brown, Anal. Chim. Acta, 1986, 181, 1). Results of single solution, binary and ternary mixtures are presented; they show maximum RSD of 3%, 10% and 15%, respectively. No adjustment of temp., I or pH was required and values of the rate constants need only be known approximately. These features make the method superior to that using proportional equations.
Spectrophotometry Kalman filter Stopped-flow Signal processing Multicomponent Kinetic

"Reversed-phase Separation Of Transition Metals, Lanthanoids And Actinoids By Elution With Mandelic Acid"
J. Chromatogr. A 1991 Volume 558, Issue 1 Pages 197-207
Steve Elchuk, Kerry I. Burns, Richard M. Cassidy and Charles A. Lucy

Abstract: A gradient concentration of 0.14 M to 0.50 M mandelic acid during 15 min was used in a mobile phase (1.0 mL min-1) of 0.01 M Na octanesulfonate at pH 4.0 for separation of lanthanoids in a column (10 cm x 4 mm) of Spherisorb C18 (3 µm), with post-column derivatization with arsenazo III for detection at 685 nm. The same column was used for separation of six actinoids in a mobile phase of 0.5 M mandelic acid in aqueous 5% acetonitrile (pH 3.2; no octanesulfonate) with similar derivatization and detection. Suitable operating concentration. were 1 mg L-1 for lanthanoids or 0.3 (Am) or 3.0 mg L-1 (others) for actinoids. Specimen chromatograms are presented and results are discussed.
HPLC Spectrophotometry Column pH Post-column derivatization

"Determination Of Lanthanides In Kola Nitrophosphate Solution By Cation-exchange Ion Chromatography"
J. Chromatogr. A 1994 Volume 671, Issue 1-2 Pages 173-179
Abdulla W. Al-Shawi* and Roger Dahl

Abstract: The digestion of Kola phosphate rock with concentrated HNO3 in the Odda process of fertilizer production leads to the dissolution of Y and lanthanides in the resulting nitrophosphate solution Mother liquor and extraction raffinate solution were diluted with water or 0.05 M HNO3 (1:100 or 1:50, respectively), filtered and a 50 µL portion was injected for analysis on a column (25 cm x 4.6 mm i.d.) of Nucleosil ET 250/8/4 SA10 or Supelcosil LC-SCX. The mobile phase was α-hydroxyisobutyric acid at a flow-rate of 1 ml/min and a concentration gradient of 0.04-0.08 M in 5 min, then to 0.3 M in 15 min at pH 3.8-4.2. Post-column derivatization with 4-(2-pyridylazo)resorcinol (PAR) or Arsenazo III was followed by detection at 530 or 658 nm, respectively. The detection limits were 100-1000 µg/l, depending on the post-column reagent and the nature of the lanthanide. The RSD (n = 10) was 0.7-3% for samples detected with PAR and 0.6-2.5% for those detected with Arsenazo III. The determination of lanthanides in organic solution is also described.
Phosphate HPIC Spectrophotometry Sample preparation Post-column derivatization

"Flow Injection Determination And Photochemical Characterization Of Eight Coordinated Chelates Of Heavy Metal Ions. 1. Electrochemical Behavior Of Light Lanthanide Ions In Nonaqueous Solution"
Anal. Sci. Tech. 1994 Volume 7, Issue 3 Pages 361-369
Kang, Sam-Woo;Pak, Chong-Min;Lee,Mi-Do;Song, Myoung-Kyu;Kim, Il-Kwang

Abstract: Voltammetric behavior of some light lanthanide ions(La+, Pr+, Nd+, Sm+ and Eu+) in acetonitrile(AN) and dimethylformamide(DMF) has been investigated by direct current, differential pulse polarography and cyclic voltammetry. The reduction of La+, Pr+ and Nd+ in 0.1 M TEAP proceeded directly to the metallic state through three-electron charge transfer of irreversible process where as Sm+ and Eu+ proceeded by charge transfer of two steps. As the results of the cyclic voltammetric investigation, the first step reduction of Sm+ and Eu+ were a quasireversible reaction, the second step reductions were an irreversible reaction. The cathodic peak currents of the differential pulse polarogram showed adsorptive properties at lower sweep rates and high concentrations of these metal ions. The peak potenital was shifted to a negative petential and the peak current decreased with the increase of percentage of water in AN. On the other hand, the peak potential was shifted to a positive potential and the peak current decreased with an increased percentage of water in DMF.
Voltammetry Polarography Spectrophotometry Organic phase detection

"Spectrophotometric Determination Of Lanthanides And Yttrium By Flow Injection Analysis Using Chrome Azurol S In The Presence Of Cationic Surfactants"
Chem. Pap. 1988 Volume 42, Issue 5 Pages 607-620
Gladilovich, D.B.;Kuban, V.

Abstract: Solutions (0.01M) of lanthanoids and Y were analyzed by flow injection analysis by mixing with a reagent containing Chrome Azurol S (C. I. Mordant Blue 29), 0.1 M ammonia buffer (pH 9.4) and hexadecyltrimethylammonium bromide, hexadecylpyridinium bromide or Septonex. Spectrophotometric detection was at 620 or 650 nm for lanthanoids or Y, respectively. This reaction can be applied in derivatization of lanthanoids after separation by HPLC or ion-exchange chromatography.
Spectrophotometry Surfactant

"Flow Injection Spectrofluorimetric Determination Of Samarium(III) Based On Quenching Of Calcein Blue Fluorescence"
Fukuoka Joshi Daigaku Kaseigakubu Kiyo 1990 Volume 21, Issue 1 Pages 5-9
AIHARA Makoto; UCHIKADO Masako

Abstract: Calcein blue has a strong fluorescence (excitation at 370 nm, emission at 440 nm) that is sensitively quenched by the presence of trivalent lanthanide ions. The analysis system consists of a reciprocating pump with two channels (one for HCl carrier solution, and another for reagent solution), a 6-way sample injection valve, a 3 m reaction coil, a spectrofluorometer with a 32 mL flow cell, a 1 m back-pressure coil, and polyethylene tube manifold (0.5 mm i.d.). A series of experiments was conducted to find the optimum analysis conditions for the system. A 100 mL of sample solution containing 10^-6 ~ 10^-4 M Sm(III) was injected into the carrier stream under the following optimum analysis conditions: concentration of reagent, 7 x 10^-5 M in tris(hydroxymethyl)[aminomethane buffer solution at pH 8.0; carrier solution, 10^-4 M HCl; flow rate, 1.0 mL min-1; and manifold tube length, 3 m. The relative standard deviation was ≤0.11%. The system can analyze 40 sample solutions per h, and can be applied to all members of the lanthanides with equal sensitivity.
Fluorescence Quenching Optimization

"Improved Separation Of Closely Related Metal Ions By Centrifugal Partition Chromatography"
J. Liq. Chromatogr. Relat. Technol. 1990 Volume 13, Issue 18 Pages 3651-3672
S. Muralidharaa; R. Cai; H. Freiser

Abstract: The separation was investigated of adjacent trivalent lanthanoids by centrifugal partition chromatography at 800 rpm with use of six cartridges, each containing 400 channels, with 20 mL of 0.1 M bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) in heptane as stationary phase and with 110 mL of water at the appropriate pH as mobile phase (1 mL min-1). The lanthanoids were determined by post-column derivatization with arsenazo III followed by 654-nm detection. Baseline separations of the adjacent lanthanoids were achieved with a column efficiency of 320 ± 40 theoretical plates, which decreased with flow rate. The distribution ratios, in most instances, agreed well with values obtained by batch solvent extraction. A mixture of light and heavy lanthanoids was separated efficiently in a single run with use of pH gradient elution, the initial pH of 3.0 being reduced stepwise by the addition of 0.5 M HCl.
Chromatography Post-column derivatization pH gradient

"Molecular Spectroscopic Methods For The Determination Of Lanthanides In Solutions"
Spectrochim. Acta Rev. 1991 Volume 14, Issue 5 Pages 337-351
Georges, Joseph

Abstract: A review with 155 references. This paper presents the spectral properties of lanthanide ions and chelates and reviews the deriving mol. spectrometric methods involved in the anal. of lanthanides. These include conventional or laser-based absorption and emission methods, such as UV-visible absorption spectrometry, thermal lens spectrometry, photoacoustic spectrometry, spectrofluorometry and laser-induced fluorescence. (SFS)
Spectrophotometry Review