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Addressing K/L-edge overlap in elemental analysis from micro-X-ray fluorescence: bioimaging of tungsten and zinc in bone tissue using synchrotron radiation and laser ablation inductively coupled plasma mass spectrometry

  • Cassidy R. VanderSchee
  • David Kuter
  • Hsiang Chou
  • Brian P. Jackson
  • Koren K. Mann
  • D. Scott BohleEmail author
Communication
  • 44 Downloads

Abstract

Synchrotron radiation micro-X-ray fluorescence (SR-μXRF) is a powerful elemental mapping technique that has been used to map tungsten and zinc distribution in bone tissue. However, the heterogeneity of the bone samples along with overlap of the tungsten L-edge with the zinc K-edge signals complicates SR-μXRF data analysis, introduces minor artefacts into the resulting element maps, and decreases image sensitivity and resolution. To confirm and more carefully delineate these SR-μXRF results, we have employed laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to untangle the problem created by the K/L-edge overlap of the tungsten/zinc pair. While the overall elemental distribution results are consistent between the two techniques, LA-ICP-MS provides significantly higher sensitivity and image resolution compared with SR-μXRF measurements in bone. These improvements reveal tissue-specific distribution patterns of tungsten and zinc in bone, not observed using SR-μXRF. We conclude that probing elemental distribution in bone is best achieved using LA-ICP-MS, though SR-μXRF retains the advantage of being a non-destructive method with the capability of being paired with X-ray techniques, which determine speciation in situ. Since tungsten is an emerging contaminant recently found to accumulate in bone, accurately determining its distribution and speciation in situ is essential for directing toxicological studies and informing treatment regimes.

Graphical abstract

Tungsten and zinc localization and uptake in mouse femurs were imaged by synchrotron radiation, left, and by laser ablation ICP-MS, right. The increased resolution of the LA-ICP-MS technique resolves the problem of the overlap in tungsten’s L-edge and zinc’s K-edge

Keywords

Tungsten LA-ICP-MS X-ray spectroscopy (XPS | XRF | EDX) Zinc Analyte Overlap 

Notes

Acknowledgements

We thank the CLS for beamtime along with Renfei Feng and Peter Blanchard for their assistance at the VESPERS beamline. Research done at the Canadian Light Source is supported by the Canada Foundation for Innovation, NSERC, the University of Saskatchewan, the Government of Saskatchewan, Western Economic Diversification Canada, the National Research Council Canada, and the CIHR. Dartmouth Trace Element Analysis Core is supported by NCI Cancer Center Support Grant 5P30CA023108-37 and NIEHS Superfund grant P42 ES007373.

Author Contributions

KKM, DSB designed the project. KKM and HC supervised sample collection from animal specimens. CRV prepared bone samples and collected BE images. CRV and DK collected, processed and analyzed SR-μ-XRF and LA-ICP-MS data. BPJ assisted with LA-ICP-MS collection and analysis. DSB, CRV and DK wrote the manuscript with input from all authors.

Funding information

This study received financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC), Canadian Institutes of Health Research (CIHR), and the Canada Research Chairs Program as well as fellowship support from the CIHR to DK and CRV.

Compliance with ethical standards

Animal experiments were performed in the Lady Davis Institute Animal Care Facility following the guidelines of the McGill University Animal Care Committee–approved protocol.

Conflict of interest

The authors declare that they have no competing interests.

Supplementary material

216_2019_2244_MOESM1_ESM.pdf (1.1 mb)
ESM 1 Table S1 Close Kα1 /Lα1 Edge overlaps distinguished by differences in edge energies in keV. Energies taken from the ALS X-ray Data Booklet [5]. Particularly close overlapping pairs such as As/Pb and Ca/Sn have been discussed before [1]. Table S2 Maximum intensity values used for scaling SR-μXRF and LA-ICP-MS maps (Figure 1 and Figure S2). Intensity scale is in normalized counts for SR-μXRF and counts for LA-ICP-MS and cannot be compared between the two techniques. Fig. S1 Backscattered electron image (BEI) of bone tibia cross-section, (a) prepared using thin-sectioning method and (b) via polishing method. Scale bar = 50 μm. Fig. S2 Tungsten (a-b) and (calcium c-d) SR-μXRF maps of longitudinally sliced murine femoral knee section. Maps (a,c) are collected at a higher resolution of 5 μm step size compared to the lower resolution maps (b,d) which have a 18 μm step size. Smaller step size does not provide further elemental distribution details compared to the larger step size. Scale bar = 50 μm. Intensity values in Table S2. Fig. S3 SR-μXRF tungsten elemental distribution map corresponding to Figure 3A (indicated in b) of longitudinally sliced murine femoral head from mouse exposed to 1000 ppm of tungsten. In (a), the lower limit corresponds to upper limit from control sample, Figure 3C. White background indicates counts below the lower limit. 16 μm step size. Scale bars = 200 μm. Fig. S4 (a-b) SR-μXRF[6] and (c-d) LA-ICP-MS maps of murine tibia and femur cross-sections, respectively, from mouse exposed to 1000 ppm of tungsten for four weeks. Similar tungsten (a,c) and zinc (b,d) distribution trends are observed. Intensity scale is in normalized counts for SR-μXRF and counts for LA-ICP-MS and cannot be compared between the two techniques. Step size: (a,b) 20 μm; (c,d) 15 μm. Scale bars = 200 μm. Fig. S5 From left to right: BEI, SR-μXRF and LA-ICP-MS calcium distribution maps of the identical longitudinally sliced murine proximal tibia sample. These images are the same magnified sections as indicated in Figure 1 (PDF 1.07 MB)

References

  1. 1.
    Ackerman CM, Lee S, Chang CJ. Analytical methods for imaging metals in biology: from transition metal metabolism to transition metal signaling. Anal Chem. 2017;89:22–41.  https://doi.org/10.1021/acs.analchem.6b04631.CrossRefPubMedGoogle Scholar
  2. 2.
    Pushie MJ, Pickering IJ, Korbas M, Hackett MJ, George GN. Elemental and chemically specific x-ray fluorescence imaging of biological systems. Chem Rev. 2014;114:8499–541.  https://doi.org/10.1021/cr4007297.CrossRefPubMedPubMedCentralGoogle Scholar
  3. 3.
    Meirer F, Pemmer B, Pepponi G, Zoeger N, Wobrauschek P, Sprio S, et al. Assessment of chemical species of lead accumulated in tidemarks of human articular cartilage by X-ray absorption near-edge structure analysis. J Synchrotron Radiat. 2011;18:238–44.  https://doi.org/10.1107/S0909049510052040.CrossRefPubMedPubMedCentralGoogle Scholar
  4. 4.
    Barrea RA, Antipova O, Gore D, Heurich R, Vukonich M, Kujala NG, et al. X-ray micro-diffraction studies on biological samples at the BioCAT Beamline 18-ID at the Advanced Photon Source. J Synchrotron Radiat. 2014;21(Pt 5):1200–5.  https://doi.org/10.1107/S1600577514012259.CrossRefPubMedPubMedCentralGoogle Scholar
  5. 5.
    Pemmer B, Roschger A, Wastl A, Hofstaetter JG, Wobrauschek P, Simon R, et al. Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue. Bone. 2013;57:184–93.  https://doi.org/10.1016/j.bone.2013.07.038.CrossRefPubMedPubMedCentralGoogle Scholar
  6. 6.
    Koutsospyros A, Braida W, Christodoulatos C, Dermatas D, Strigul N. A review of tungsten: from environmental obscurity to scrutiny. J Hazard Mater. 2006;136(1):1–19.  https://doi.org/10.1016/j.jhazmat.2005.11.007.CrossRefPubMedGoogle Scholar
  7. 7.
    Strigul N. Does speciation matter for tungsten ecotoxicology? Ecotoxicol Environ Saf. 2010;73:1099–113.  https://doi.org/10.1016/j.ecoenv.2010.05.005.CrossRefPubMedGoogle Scholar
  8. 8.
    Bolt AM, Sabourin V, Molina MF, Police AM, Negro Silva LF, Plourde D, et al. Tungsten targets the tumor microenvironment to enhance breast cancer metastasis. Toxicol Sci. 2015;143:165–77.  https://doi.org/10.1093/toxsci/kfu219.CrossRefPubMedGoogle Scholar
  9. 9.
    Lemus R, Venezia CF. An update to the toxicological profile for water-soluble and sparingly soluble tungsten substances. Crit Rev Toxicol. 2015;45:388–411.  https://doi.org/10.3109/10408444.2014.1003422.CrossRefPubMedPubMedCentralGoogle Scholar
  10. 10.
    Guandalini GS, Zhang L, Fornero E, Centeno JA, Mokashi VP, Ortiz PA, et al. Tissue distribution of tungsten in mice following oral exposure to sodium tungstate. Chem Res Toxicol. 2011;24:488–93.  https://doi.org/10.1021/tx200011k.CrossRefPubMedGoogle Scholar
  11. 11.
    Aaseth J, Boivin G, Andersen O. Osteoporosis and trace elements – an overview. J Trace Elem Med Biol. 2012;26(2):149–52.  https://doi.org/10.1016/j.jtemb.2012.03.017.CrossRefPubMedGoogle Scholar
  12. 12.
    Pounds JG, Long GJ, Rosen JF. Cellular and molecular toxicity of lead in bone. Environ Health Perspect. 1991;91:17–32.  https://doi.org/10.1289/ehp.919117.CrossRefPubMedPubMedCentralGoogle Scholar
  13. 13.
    VanderSchee CR, Kuter D, Bolt AM, Lo F-C, Feng R, Thieme J, et al. Accumulation of persistent tungsten in bone as in situ generated polytungstate. Commun Chem. 2018;1:8.  https://doi.org/10.1038/s42004-017-0007-6.CrossRefGoogle Scholar
  14. 14.
    Wang S-S, Yang G-Y. Recent advances in polyoxometalate-catalyzed reactions. Chem Rev. 2015;115(11):4893–962.  https://doi.org/10.1021/cr500390v.CrossRefPubMedGoogle Scholar
  15. 15.
    Kelly ADR, Lemaire M, Young YK, Eustache JH, Guilbert C, Molina MF, et al. In vivo tungsten exposure alters B-cell development and increases DNA damage in murine bone marrow. Toxicol Sci. 2013;131:434–46.  https://doi.org/10.1093/toxsci/kfs324.CrossRefPubMedGoogle Scholar
  16. 16.
    Diwakar PK, Gonzalez JJ, Harilal SS, Russo RE, Hassanein A. Ultrafast laser ablation ICP-MS: role of spot size, laser fluence, and repetition rate in signal intensity and elemental fractionation. J Anal At Spectrom. 2014;29(2):339–46.  https://doi.org/10.1039/C3JA50315A.CrossRefGoogle Scholar
  17. 17.
    Austin C, Smith TM, Bradman A, Hinde K, Joannes-Boyau R, Bishop D, et al. Barium distributions in teeth reveal early-life dietary transitions in primates. Nature. 2013;498:216–9.  https://doi.org/10.1038/nature12169.CrossRefPubMedPubMedCentralGoogle Scholar
  18. 18.
    Trog S, El-Khatib AH, Beck S, Makowski MR, Jakubowski N, Linscheid MW. Complementarity of molecular and elemental mass spectrometric imaging of Gadovist™ in mouse tissue. Anal Bioanal Chem. 2019;411(3):629–37.CrossRefGoogle Scholar
  19. 19.
    Halbach K, Wagner S, Scholz S, Luckenbach T, Reemtsma T. Elemental imaging (LA-ICP-MS) of zebrafish embryos to study the toxicokinetics of the acetylcholinesterase inhibitor naled. Anal Bioanal Chem. 2019;411(3):617–27.  https://doi.org/10.1007/s00216-018-1471-2.CrossRefPubMedGoogle Scholar
  20. 20.
    Sussulini A, Becker JS, Becker JS. Laser ablation ICP-MS: application in biomedical research. Mass Spectrom Rev. 2017;36(1):47–57.  https://doi.org/10.1002/mas.21481.CrossRefPubMedGoogle Scholar
  21. 21.
    Bellis DJ, Hetter KM, Jones J, Amarasiriwardena D, Parsons PJ. Calibration of laser ablation inductively coupled plasma mass spectrometry for quantitative measurements of lead in bone. J Anal At Spectrom. 2006;21:948–54.  https://doi.org/10.1039/b603435g.CrossRefPubMedPubMedCentralGoogle Scholar
  22. 22.
    ATSDR. Toxicological profile for tungsten. In: U.S. Department of Health and Human Services PHS, editor. Atlanta, GA2015. p. 11-2.Google Scholar
  23. 23.
    Li L, Yan H, Xu W, Yu D, Heroux A, Lee W-K, Campbell SI, Chu YS, editors. PyXRF: Python-based X-ray fluorescence analysis package. SPIE Optical Engineering + Applications; 2017: SPIE.Google Scholar
  24. 24.
    Szczerbowska-Boruchowska M. Sample thickness considerations for quantitative X-ray fluorescence analysis of the soft and skeletal tissues of the human body – theoretical evaluation and experimental validation. X-Ray Spectrom. 2012;41(5):328–37.  https://doi.org/10.1002/xrs.2407.CrossRefGoogle Scholar
  25. 25.
    Blaske F, Reifschneider O, Gosheger G, Wehe CA, Sperling M, Karst U, et al. Elemental bioimaging of nanosilver-coated prostheses using X-ray fluorescence spectroscopy and laser ablation-inductively coupled plasma-mass spectrometry. Anal Chem. 2014;86:615–20.  https://doi.org/10.1021/ac4028577.CrossRefPubMedGoogle Scholar
  26. 26.
    Wang HAO, Grolimund D, Loon LRV, Barmettler K, Borca CN, Aeschlimann B. Quantitative chemical imaging of element diffusion into heterogeneous media using laser ablation inductively coupled plasma mass spectrometry, synchrotron micro-x-ray fluorescence, and extended x-ray absorption fine structure spectroscopy. Anal Chem. 2011;83:6259–66.  https://doi.org/10.1021/ac200899x.CrossRefPubMedGoogle Scholar
  27. 27.
    Davies KM, Hare DJ, Bohic S, James SA, Billings JL, Finkelstein DI, et al. Comparative study of metal quantification in neurological tissue using laser ablation-inductively coupled plasma-mass spectrometry imaging and x-ray fluorescence microscopy. Anal Chem. 2015;87:6639–45.  https://doi.org/10.1021/acs.analchem.5b01454.CrossRefPubMedGoogle Scholar
  28. 28.
    Marquet P, François B, Vignon P, Lachâtre G. A soldier who had seizures after drinking quarter of a litre of wine. Lancet. 1996;348(9034):1070.  https://doi.org/10.1016/S0140-6736(96)05459-1.CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Cassidy R. VanderSchee
    • 1
  • David Kuter
    • 1
  • Hsiang Chou
    • 2
  • Brian P. Jackson
    • 3
  • Koren K. Mann
    • 2
  • D. Scott Bohle
    • 1
    Email author
  1. 1.Department of ChemistryMcGill UniversityMontrealCanada
  2. 2.Lady Davis Institute for Medical ResearchMcGill UniversityMontrealCanada
  3. 3.Department of Earth SciencesDartmouth CollegeHanoverUSA

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