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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Gadolinium

  • IUPAC Name: gadolinium
  • Molecular Formula: Gd
  • CAS Registry Number: 7440-54-2
  • InChI: InChI=1S/Gd
  • InChI Key: UIWYJDYFSGRHKR-UHFFFAOYSA-N

@ ChemSpider@ NIST@ PubChem

Citations 9

"A Micro-scale Mercury Cathode Electrolysis Procedure For Online Flow Injection Inductively Coupled Plasma Mass Spectrometry Trace Elements Analysis In Steel Samples"
Anal. Chim. Acta 1999 Volume 389, Issue 1-3 Pages 247-255
Aurora G. Coedo, Isabel Padilla, Teresa Dorado and Francisco J. Alguacil

Abstract: An online matrix-analyte separation technique was developed for flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS) trace analysis. A µelectrolytic cell was designed to be inserted in the FI manifold. The technique was used to separate Zr, Hf, Y, rare earth elements (REEs), Th and U from a steel-matrix (Fe, Cr, Ni, Co, Mn and Mo). A microwave-assisted HNO3-HCl-HF-H2SO4 digestion procedure, with temperature/pressure regulation, was used for sample dissolution. Obtained solutions were evaporated to SO3 fumes, and 2 mi of this diluted sulfuric solution were introduced in the electrolytic cell through the manifold circuit. After matrix removal, the electrolyte was conducted to load a 300 µl sample loop to be injected into the plasma torch. Direct multielement standard solutions in diluted sulfuric acid (without matrix matching and sample pretreatment) were applied for external calibration. The determination limits, with reference to the solid, were improved by a factor of about 10 compared with that obtained from direct measurements of 0.1% (m/v) sample solutions. The relative standard deviations for all the analytes were better than 3.5% for concentrations above 10 times the limit of quantification. The developed method was applied in the determination of certified elements in Steel Reference Materials: NIST 363 and NIST 364. Recoveries from 0.200 g test portions of high-purity iron spiked at two different concentration levels were found better than 97%.
NIST 363 NIST 364 Mass spectrometry Matrix removal Extraction

"Micellar Systems In Flow Injection: Determination Of Gadolinium With 1-(2-pyridylazo)-2-naphthol In The Presence Of Triton X-100"
Analyst 1992 Volume 117, Issue 2 Pages 215-217
José Luis Pérez Pavón and Bernardo Moreno Cordero

Abstract: The determination of Gd by using the cited flow injection method was optimized. Sample solution (pH 2.2) containing Gd was injected in presence of 0.4 M NaNO3 into a stream (4.4 mL min-1) of borate buffer solution (pH 9.2) containing 1.2 M 1-(2-pyridylazo)-2-naphthol (PAN) - Triton X-100 (1:150) and passed through a 20 cm mixing coil. Detection was at 560 nm. The calibration graph was rectilinear from 0.9 to 8.8 ppm of Gd. At 1.5 ppm of Gd the coefficient of variation (n = 10) was 0.48%. Oxalate, PO43-, lanthanoids and citrate interfered. Interference by heavy metals (except Ce(IV)) was eliminated by extraction of their diethyldithiocarbamate complexes into CHCl3 - ethyl acetate (1:1). Interfering Ce(IV) was precipitated. with KBrO3. The optimum conditions for the determination of Gd using the Gd-1-(2-pyridylazo)-2-naphthol (PAN) system in micelles of Triton X-100 have been studied. Under the conditions chosen, the molar absorptivity was 4.8 x 10^4 L mol-1 cm-1. It is possible to determine Gd at levels of between 0.9 and 8.8 µg mL-1 by injection into a stream, buffered at pH 9.2, containing 1.2 x 10^-3 mol L-1 PAN (Triton X-100:PAN = 0.15 g:1.0 mg). The influence of the presence of electrolytes in the matrix on peak height was studied. The interferences produced by heavy metals were eliminated by extracting their diethyldithiocarbamates into CHCl3-EtOAc (1 + 1).
Spectrophotometry Micelle Surfactant Triton X Optimization Interferences

"Determination Of Trace Metals In Uranium Oxide By Inductively Coupled Plasma Mass Spectrometry Combined With Online Solvent Extraction"
J. Anal. At. Spectrom. 1992 Volume 7, Issue 3 Pages 565-569
S. Vijayalakshmi, R. Krishna Prabhu, T. R. Mahalingam and C. K. Mathews

Abstract: An online solvent extraction technique for the determination of trace elements in uranium by inductively coupled plasma mass spectrometry is described. An aqueous solution containing uranium (2% m/v) in 1 mol L-1 nitric acid and an organic solvent that can effectively ext. uranium, viz., trioctylphosphine oxide in cyclohexane (0.2 mol L-1), are pumped alternately through a poly(tetrafluoroethylene) (PTFE) tube where they mix thoroughly. The organic phase containing the extd. uranium is removed online by allowing the solution to pass through a microporous PTFE tube which, being hydrophobic, selectively allows the organic phase to permeate through its walls. This technique facilitates rapid and sensitive determination of trace elements in uranium with detection levels in the range 1-45 ppb for La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb, Ag, Ba, Cd, Co, Cr, Cu, In, Li, Mn, Ni, Pb, Sr, Ti, V and Y, 0.1 ppm for Al and 0.5 ppm for Fe. flow rate of about 4 mL min-1 was used.
Inorganic compound Mass spectrometry Sample preparation Solvent extraction Teflon membrane

"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

"Rare-earth Ion-selective Electrodes"
Electroanalysis 1993 Volume 5, Issue 9-10 Pages 863-867
Yonghua Zhang, Jinlan Wu, Erkang Wang

Abstract: Copolymers obtained by radiation grafting of high-density polyethylene, polypropene, PVC, polystyrene or polyacrylonitrile with acrylic acid were treated with a solution of rare-earth chloride by IR heating for 18 h, and the resulting materials were heat-pressed to form membranes for use in ISE. Membranes incorporating Gd, Pr, Nd or Yb, used at the optimum pH of 4.5-6.5, 5.5-6.4, 5.5 and 5.5-6.5, respectively, had corresponding linear response ranges of 0.002-10 mM, 0.5-100 mM, 0.002-10 mM and The membranes could be used in a flow-through cell detector for FIA. The selectivity coefficients for a Gd-selective electrode are tabulated. Electrodes were also prepared from ignited rare-earth oxides; e.g., 50-56% of cerium oxide was mixed with epoxy-resin and carboxy-terminated butadiene-acrylonitrile copolymer to form a Ce electrode for the range 10 µM-0.1 M Ce3+, -La3+, -Nd3+, -Pr3+ or -Sm3+. Electrodes based on lanthanum oxide or Dy2O3 were also prepared. Chelates of Nd with 4-benzoyl-3-methyl-1-phenylpyrazolin-5-one, Yb with 2-ethylhexyl 2-ethylhexylphosphate and Sm(NO3)3 with TBP were used to prepare Nd, Yb and Sm electrodes, respectively.
Electrode Electrode Electrode Electrode Electrode Selectivity Detector

"Reversed-phase Chromatographic Separation Of The Rare-earth Elements"
Chromatographia 1990 Volume 29, Issue 11-12 Pages 579-582
M. Adachi, K. Oguma and R. Kuroda

Abstract: Rare-earth metals (1 mM to 4 mM in 3 M HCl) were separated by HPLC on a column (15 cm x 4 mm) of Hitachi ODS (5 µm) with a mobile phase (1.0 mL min-1) of 0.05 M to 0.5 M lactic acid (gradient concentration.) containing 10 mM octanesulfonate and aqueous NH3 to pH 3.5. The eluate was derivatized post-column with 0.1 mM arsenazo III and detection was at 650 nm. Separation was completed within 40 min. Specimen chromatograms are presented; there was co-elution of Dy with Y and of Eu with Gd. Detection limits were down to ~ 10 ng injected.
HPLC Spectrophotometry Post-column derivatization Detection limit

"Simultaneous Determination Of Individual Rare-earth Elements In The Binary Mixture Of Gadolinium And Yttrium By Flow Injection Rate Differential Kinetic Spectrophotometry"
Fenxi Huaxue 1992 Volume 20, Issue 4 Pages 399-402
Fu, L.;Ren, Y.

Abstract: Gadolinium and Y were determined simultaneously in a series of synthetic samples with a content ratio of Gd:Y of 1:8 to 8:1. The sample solution was mixed with 5 mL of HCl - Na acetate buffer solution (pH 3), 3.5 mL of aqueous 0.05% trichloroarsenazo (I) and water to 25 mL. The solution was analyzed by the cited method in a flow injection system (diagram given) with Gd (or Y) - I complex solution as carrier solution After adding 1 mM CDTA, the peak height was recorded at 636 nm vs. a blank. Recovery was 90 to 110%.
Spectrophotometry Simultaneous analysis Complexation Kinetic

"Gadolinium Ion-selective Electrode And Its Application In Flow Injection Analysis"
Fenxi Huaxue 1992 Volume 20, Issue 5 Pages 611-615
Wu, J.;Zhang, Y.

Abstract: A Gd3+-sensing membrane was prepared with functional polymers as active material. The ion-selective electrode comprised the membrane sensor, a Ag - AgCl reference electrode and 10 mM GdCl3 as internal reference solution The electrode was applied to the flow injection determination of Gd3+ and exhibited a Nernstian response from 10 mM to 5 µM-Gd. The detection limit was 2.5 µM and the coefficient of variation was 1.5%.
Electrode Electrode Apparatus Detector

"Study On The Flow Injection Analysis ICP-AES Spectrographic Method. 1. Determination Of Fourteen Rare Earth Impurities In High-purity Yttrium Oxide"
J. Rare Earths 1988 Volume 6, Issue 1 Pages 65-69
Chen, Hao; Jiang, Zucheng; Zen, Yune; Kong, Linying (SFS)

Abstract: Flow-injection analysis-inductively coupled plasma-atomic emission spectrometric (FIA-ICP-AES) method for the determination of 14 rare earth impurities in high-purity yttrium oxide was developed. The effects of some factors including length of transportation tube, volume of sample, exposure time, ICP working parameters, acidity and matrix concentration. were investigated. The dispersion ratio of FIA-ICP-AES method for the given condition was calculated from experimental results. Under optimum conditions the detection limits of different impurities in the method proposed are from 0.25 to 12.5 to mg/g and relative standard deviation in the range of 1.0-2.9%. This method was used for the determination of trace amounts of rare earth impurities in 99-99.99% of yttrium oxide, and their results are in good agreement with those obtained by continuous pneumatic nebulization (CPN)-ICP-AES method. In comparison with the CPN-ICP-AES method, the FIA-ICP-AES is superior in efficiency, precision, influence of acidity and matrix effect, atmosphere of sample used, and permissible concentration of salt. The sensitivity loss in FIA-ICP-AES can be compensated by increasing matrix concentration. in solution This method can be applied to the routine analysis in the rare earth industry. (SFS)
High purity Spectrophotometry Optimization Method comparison