SciELO - Scientific Electronic Library Online

 
vol.63Synthesis, spectroscopic and pharmacological studies of bivalent copper, zinc and mercury complexes of thioureaIodination of alcohols over Keggin-type heteropoly compounds: A simple, selective and expedient method for the synthesis of alkyl lodides author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Article

Indicators

Related links

  • On index processCited by Google
  • On index processSimilars in Google

Share


South African Journal of Chemistry

On-line version ISSN 1996-840X
Print version ISSN 0379-4350

S.Afr.j.chem. (Online) vol.63  Durban  2010

 

RESEARCH ARTICLE

 

Alternative dissolution methods for analysis of niobium containing samples

 

 

Motlalepula NeteI; Walter PurcellI*; Ettienne SnydersII; Johann T. NelII

IDepartment of Chemistry, University of the Free State, Bloemfontein 9300, South Africa
IIThe South African Nuclear Energy Corporation Ltd. (Necsa), P.O. Box 582, Pretoria 0001, South Africa

 

 


ABSTRACT

Inductively coupled plasma optical emission spectrometry was applied for the qualitative and quantitative analyses of the different high purity Nb containing samples such as Nb metal, Nb2O5 and NbF5. Microwave-assisted digestion of the Nb compounds with concentrated H2SO4 in PTFE vessels produced Nb recoveries of 99.90 ± 0.08 % for Nb metal, 98.8 ± 0.7 % for Nb2O5 and 100.7 ± 0.4 % for NbF5. Fusion of Nb2O5 with Li2B4O7 flux and the subsequent dissolution of the melt with concentrated H2SO4 resulted in the precipitation of H3BO3 under these conditions. Methanol was added to the reaction mixture to convert the boric acid into the volatile methyl ester in an effort to remove the excess H3BO3. This procedure yielded a recovery of 103±2%for the pure Nb2O5 sample.

Keywords: Niobium samples, microwave dissolution, fusion dissolution, qualitative analysis, quantitative analysis, validation


 

 

Full text available only in PDF format.

 

 

References

1 A. Jones, Metall, 1988, 42, 117-119.         [ Links ]

2 J. Eckert, C. Hermann, Ullmann's Encyclopedia of Industrial Chemistry, Niobium and Niobium Compounds, A17, VCH Verlagsgesellschaft, Weinheim, 1996, pp. 251-264.         [ Links ]

3 M. del C. Ruiz, M.H. Rodriguez, E. Perino and R.A. Olsina, Miner Eng., 2002, 15, 373-375.         [ Links ]

4 K.S. Park, N.B. Kim, H.J. Woo, K.Y. Lee, Y.Y. Yoon and W. Hong, J. Radioanal. Nucl. Chem., 1994, 179(1), 81-86.         [ Links ]

5 K. Tanabe, Mater. Chem. Phys, 1987, 17, 217-225.         [ Links ]

6 P. Roy, V. Balaram, A. Bhattacharaya, P. Nasipuri and M. Satyana-rayanan, Res. Commun., Curr. Sci, 2007, 93(8), 1122-1126.         [ Links ]

7 J.E. Zola, ed., Chemical Safety Data Guide, Bureau of National Affairs, Washington, DC, 1985, 475-476.         [ Links ]

8 A.M. Trevino, Hydrofluoric Acid Exposures Long-term Effects, October 1991 Draft. (485).         [ Links ]

9 S.K. Mudan, Acute Inhalation Toxicity of Hydrogen Fluoride, AlChE Summer Annual Meeting, Philadelphia, 24-26 August, 1989, p. 360.         [ Links ]

10 C. Qing, T. Shibata, K. Shinotsuka, M. Yoshikawa and Y. Tatsumi, Frontier Research on Earth Evolution, 2003, 1, 357-362.         [ Links ]

11 R.A. Conte, J.M. Mermet, J.D.A. Rodrigues and J.L. Martino, J. Anal. At. Spectrom., 1997, 12, 1215-1220.         [ Links ]

12 O.N. Grebneva, I.V Kubrakova, T.F. Kudinova, and N.M. Kuz'min, Spectrochim. Acta, Part B, 1997, 52, 1151-1159.         [ Links ]

13 J.E.S. Uria, C.G. Ortiz, A.M. Garcia and A. Sanz-Medel, Microchim. Acta [Wien], 1987, 2, 195-202.         [ Links ]

14 G.E.M. Hall and J.C. Pelchat, J. Anal. At. Spectrom., 1990, 5. 339-349.         [ Links ]

15 M. Archer, R.I. McCrindle and E.R. Rohwer, J. Anal. At. Spectrom., 2003, 18, 1493-1496.         [ Links ]

16 R.P.S. Gaur and R.G. Mendenhall, United States Patent US 7182925 B2, 27 Feb., 2007.         [ Links ]

17 H. Zhou, D. Yi, Y. Zhang and S. Zheng, Hydrometallurgy, 2005, 80, 126-131.         [ Links ]

18 S.B. Dampare, B.J. B. Nyarko, S. Osae, E.H.K. Akaho, D.K. Asiedu, Y. Serfor-Armah, and P. Nude, J. Radioanal. Nucl. Chem., 2005, 265 (1), 53-59.         [ Links ]

19 S. Li, B. Hu and Z. Jiang, J. Anal. At. Spectrom. 2004, 19, 387-391.         [ Links ]

20 D. Huang and V. Krivan, Fresenius J. Anal. Chem., 2000, 368, 227-234.         [ Links ]

21 R.K. Winge, V.A. Fassel, V.J. Peterson, and M.A. Floyd, Inductively Coupled Plasma - Atomic Emission Spectroscopy. An Atlas of Spectral Information, Elsevier Science Publishers B.V., Amsterdam, 1993, Appendix B.         [ Links ]

22 Optima Simultaneous Spectrometers Wavelength Tables. Perkin Elmer Instruments, Life and Analytical Sciences (Pty.) Ltd., Shelton, 2002.         [ Links ]

23 D.A. Skoog, F.J. Holler and A.T. Nieman, Principles ofInstrumental Analysis, 5th edn., Saunders College Publishing, Philadelphia, 1998, p. 12.         [ Links ]

24 D.A. Skoog, D.M. West, F.J. Holler and S.R. Crouch, Fundamentals of Analytical Chemistry, 8th edn., Thomson Brooks/Cole, Belmont, 2004, p. 214.         [ Links ]

25 J. Takahashi and K. Youno, Agilent Technologies, Japan, Agilent ICP-MS Journal, 2003, p. 6.         [ Links ]

26 K. Nakamoto, M. Margoshes and R.E. Rundle, J. Am. Chem. Soc. 1955, 77, 6480-6488.         [ Links ]

27 D. Peak, G.W. Luther and D.L. Sparks, Geochim. Cosmochim. Acta, 2003, 67(14), 2551-2560.         [ Links ]

28 K. Nakamoto, Infrared Spectra of Inorganic and Coordination Compounds, 2nd edn., Wiley-Interscience, New York, 1969, p. 97.         [ Links ]

29 R.C. Weast, Handbook ofChemistry and Physics, 49th edn., The Chemical Rubber Co., Cleveland, 1968-1969, B-182-B-183.         [ Links ]

30 http://en.wikpedia.org/wiki/Boric_acid, retrieved 29 July 2010.         [ Links ]

31 K. Dash, S. Thangavel, S.M. Dhavile, S.V. Rao, S.C. Chaurasia and J. Arunachalam, Anal. Chim. Acta, 2005, 546, 229-235.         [ Links ]

 

 

Received 12 April 2010
Revised 5 August 2010
Accepted 12 August 2010

 

 

* To whom correspondence should be addressed. E-mail: purcellw@ufs.ac.za

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License