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Can the provenance of the conflict minerals columbite and tantalite be ascertained by laser-induced breakdown spectroscopy?

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Abstract

Conflict minerals is a term applied to ores mined in conditions of armed conflict and human rights abuse. Niobium and tantalum are two rare metals whose primary natural occurrence is in the complex oxide minerals columbite and tantalite, the ore of which is commonly referred to as coltan. The illicit export of coltan ore from the Democratic Republic of the Congo is thought to be responsible for financing the ongoing civil conflicts in this region. Determining the chemical composition of an ore is one of the means of ascertaining its provenance. Laser-induced breakdown spectroscopy (LIBS) offers a means of rapidly distinguishing different geographic sources for a mineral because the LIBS plasma emission spectrum provides the complete chemical composition (i.e., “chemical fingerprint”) of any material in real time. To test this idea for columbite–tantalite, three sample sets were analyzed. Partial least squares discriminant analysis (PLSDA) allows correct sample-level geographic discrimination at a success rate exceeding 90%.

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Acknowledgments

This research was supported by Army Research Laboratory Fellow funding to RSH and financial support to KMS from the II–VI Foundation and was facilitated by technical support from Applied Spectra, Inc.

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Authors and Affiliations

  1. Environmental Sciences Division, ARL Army Research Office, Durham, NC, 27709, USA

    Russell S. Harmon

  2. Department of Chemistry, Juniata College, Huntingdon, PA, 16652, USA

    Katrina M. Shughrue & Richard R. Hark

  3. Department of Electrical and Computer Engineering, Clarkson University, Potsdam, NY, 13699, USA

    Jeremiah J. Remus

  4. Department of Mineral Sciences, Smithsonian Institution, Washington, DC, 20013, USA

    Michael A. Wise

  5. Applied Spectra, Inc., Fremont, CA, 94538, USA

    Lucille J. East

Authors
  1. Russell S. Harmon
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  2. Katrina M. Shughrue
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  3. Jeremiah J. Remus
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  4. Michael A. Wise
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  5. Lucille J. East
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  6. Richard R. Hark
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Corresponding author

Correspondence to Richard R. Hark.

Additional information

Published in the special issue Laser-Induced Breakdown Spectroscopy with Guest Editors Jagdish P. Singh, Jose Almirall, Mohamad Sabsabi, and Andrzej Miziolek.

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Harmon, R.S., Shughrue, K.M., Remus, J.J. et al. Can the provenance of the conflict minerals columbite and tantalite be ascertained by laser-induced breakdown spectroscopy?. Anal Bioanal Chem 400, 3377–3382 (2011). https://doi.org/10.1007/s00216-011-5015-2

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  • DOI: https://doi.org/10.1007/s00216-011-5015-2

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