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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Holmium

  • IUPAC Name: holmium
  • CAS Registry Number: 7440-60-0
  • InChI: InChI=1S/Ho
  • InChI Key: KJZYNXUDTRRSPN-UHFFFAOYSA-N

@ ChemSpider@ NIST@ PubChem

Citations 6

"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

"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

"Determination Of Some Rare Earth Elements In Seawater By Inductively Coupled Plasma Mass Spectrometry Using Flow Injection Preconcentration"
Spectrochim. Acta B 1998 Volume 53, Issue 9 Pages 1281-1287
O. Vicente, a, A. Padróa, L. Martineza,*, R. Olsinab and E. Marchevskyb

Abstract: An online Eu, Tb, Ho, Tm and Lu pre-concentration and determination system implemented with inductively coupled plasma mass spectrometry associated to a flow injection method was studied. Quinolin-8-ol and Amberlite XAD-7 were used for the retention of Eu, Tb, Ho, Tm and Lu, at pH 10.0. The rare earth elements were re-extd. from the microcolumn with nitric acid. The detection limits for the pre-concentration of 100 mL of aqueous solution of Eu, Tb, Ho, Tm and Lu were 0.016, 0.0023, 0.0017, 0.0035 and 0.0015 pg/mL, respectively, with a relative standard deviation of ~2.0%. The calibration graphs obtained using the pre-concentration system for Eu, Tb, Ho, Tm and Lu were linear at levels near the detection limits up to at least 1 ng/mL. The method was applied to the determination of Eu, Tb, Ho, Tm and Lu in seawater samples.
Sea Mass spectrometry Preconcentration Amberlite 8-Hydroxyquinoline pH

"Spectrophotometric Determination Of Lanthanoids With 4-(2-pyridylazo)resorcinol By Flow Injection Analysis"
Analusis 1992 Volume 20, Issue 5 Pages 269-274
CHARTIER A. ; FOX C. G. ; GEORGES J.

Abstract: Sample solution (10 µL) of 10 mM Tb, -Ho or -Eu prepared from the corresponding chloride in 20 mM NaCl - 2 mM HCl (1:1; solution a) was injected into a steam of solution a which merged merged with a stream of 5 mM 4-(2-pyridylazo)resorcinol in 25 mM borax - 0.1 M NaOH buffer of pH 9.7. The mixture was passed through a PTFE T-piece connected to a knitted PTFE tube reactor (1 m x 0.3 mm) before its absorbance was measured at 515 nm. The calibration graph was rectilinear for 0.1 to ~10 µM-Tb, -Ho and -Eu; corresponding detection limits were 16.5, 15.9 and 15.2 ng mL-1, respectively. The results were comparable with those obtained by other techniques. A dual-line flow injection system is described for the spectrophotometric determination of terbium, holmium, and europium by complexation with 4-(2-pryidylazo)resorcinol (PAR). The first line contained a 1:1 mixture of 2 x 10^-2 M sodium chloride and 2 x 10^-2 M HCl, and the second line, the buffered PAR solution (10-4M, pH 9.7). 10 µL samples of Tb, Ho, and Eu were injected into the first line. Each lanthanide was made to react with the PAR solution at a teflon T-piece connected to a 1-m knitted teflon tube reactor (0.3 mm internal diameter). The PAR-Tb, -Ho, and -Eu complexes were detected at the output by a UV-visible spectrophotometer working at 515 nm. The linear detection range for each lanthanide extended from 10^-7 M to just above 10^-5M.
Spectrophotometry Knotted reactor Method comparison Linear dynamic range

"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