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Radionuclides

DGT can be used for measuring, monitoring and investigating radionuclides. If the element is in a chemical form that binds to one of the standard DGT binding agents, as is the case for Pu(1-4) or U(4-12), the DGT passive samplers with a binding layer of Chelex-100 (for Pu) or titanium oxide (for U) can be used in the normal way. Analysis by high resolution ICP-MS or accelerator mass spectrometry (AMS) allows identification of the individual isotope. AMS in particular has extremely low detection limits for a range of DGT-measurable elements such as the actinides, Al and Ca, making possible the measurement of rare isotopes in low-contaminant concentration environments13. This also extends the scope of DGT to the measurement of cosmogenic radionuclides such as 26Al and 41Ca. Al and Ca can be measured by DGT passive samplers with a Chelex-100 binding layer14,15, however only short (<24 hour) DGT deployments are recommended for Ca. In laboratory experiments where no other radioactive component is present it is possible to use a counting spectrometer to quantify the element. This simple counting approach can be used for field deployed DGT passive samplers if the binding agent used is selective for the single element of interest. For example, 99Tc was measured in seawater using a DGT passive sampler with a selective TEVA binding agent(16). Quantification of an eluted solution was by liquid scintillation spectrometry in this case. 137Cs was measured in a slightly acidic freshwater using a DGT passive sampler equipped with a AMP (ammonium molybdophosphate) binding layer(17). The selectivity of this binding agent for Cs allowed direct counting. Partially dried binding gels were simply placed directly onto the surface of the detector of a gamma spectrometer. The authors claimed an ideal counting geometry and exceptionally good sensitivity. However, later work has questioned the stability of this binding layer in neutral solutions(18). A DGT passive sampler equipped with a MnO2 binding agent has proved to be suitable for measuring 226Ra(8).

Standard DGT products

For measurements of Pu, the standard DGT Chelex passive samplers can be used.
For waters: LSNM-NP
For soils: LSLM-NP
For sediments: LSPM-NP

For measurement of U in freshwater, the above passive samplers can be used, but a titanium oxide binding layer is recommended.
For waters: LSNT-NP
For soils: LSLT-NP
For sediments: LSPT-NP

For measurement of Tc, a DGT passive sampler with a TEVA binding layer is recommended.
For waters: LSNV-NP
For soils: LSLV-NP
For sediments: LSPV-NP

Only the above passive samplers are supplied as standard, but on request we can make some passive samplers with bespoke binding layers. Please email info@dgtresearch.com to enquire about specific requirements.

References

  1. R. Cusnir, P. Steinmann, F. Bochud, P. Froidevaux, A DGT Technique for Plutonium Bioavailability Measurements, Environ. Sci. Technol., 48 (2014) 10829-10834.
    (Develops a DGT passive sampler method using a Chelex binding layer and alpha spectrometry.)

  2. R. Cusnir, M. Jaccard, C. Bailat, M.Christl, P. Steinmann, M. Haldimann, F. Bochud, P. Froidevaux, Probing the Kinetic Parameters of Plutonium-Naturally Occurring Organic Matter Interactions in Freshwaters Using the Diffusive Gradients in Thin Films Technique. Environ. Sci. Technol., 50 (2016) 5103-5110.
    (Uses a Chelex DGT passive sampler and alpha spectrometry to investigate Pu speciation.)

  3. R. Cusnir, M. Christl, P. Steinmann, F. Bochud, P. Froidevaux, Evidence of Plutonium Bioavailability in Pristine Freshwaters of a Karst System of the Swiss Jura Mountains. Geochim. Cosmochim. Acta, 206 (2017) 30-39.
    (Direct measurement of Pu in freshwater systems using a Chelex DGT passive sampler and quantification by accelerator mass spectroscopy.)

  4. R. Cusnir, P. Steinmann, M. Christl, F. Bochud, F. P. Froidevaux, Speciation and bioavailability measurements of environmental plutonium using diffusion in thin films. Journal of visualized experiments, 105 (2015) (doi: 10.3791/53188).
    (Describes experimental DGT methodology illustrated by a video)

  5. C.M. Hutchins, J.G. Panther, P.R. Teasdale, F. Wang, R.R. Stewart, W.W. Bennett, H. Zhao, Evaluation of a titanium dioxide-based DGT technique for measuring inorganic uranium species in fresh and marine waters, Talanta 97 (2012) 550–556.
    (Demonstrates limitations of using DGT passive samplers with Chelex and TiO2 binding layers for U, especially in seawater.)

  6. G.S. Turner, G.A. Mills, P. R. Teasdale, J.L. Burnett, S. Amos, G.R. Fones, Evaluation of DGT techniques for measuring inorganic uranium species in natural waters: Interferences, deployment time and speciation, Analytica Chimica Acta 739 (2012) 37– 46.
    (Compares DGT passive samplers for U equipped with Chelex, TiO2 or MnO2 binding layers. All worked for freshwater, but MnO2 was best in seawater.)

  7. J. Drozdzak, M. Leermakers, Y. Gao, V. Phrommavanh, M. Descostes, Evaluation and application of Diffusive Gradients in Thin Films (DGT) technique using Chelex®-100, Metsorb™ and Diphonix® binding phases in uranium mining environments, Anal. Chim. Acta 889 (2015) 71–81.
    (Compares performance DGT passive samplers for U equipped with Chelex, TiO2 or Diphonix binding layers. The conclusions favour Diphonix.)

  8. M. Leermakers, V. Phrommavanh, J. Drozdzak, Y. Gao, J. Nos, M.J.C. Descostes, DGT as a useful monitoring tool for radionuclides and trace metals in environments impacted by uranium mining, case study of the Sagnes wetland in France 155 (2016) 142–151.
    (U measured by DGT (Chelex) and 226Ra by DGT (MnO2) with HR-ICP-MS detection are compared to size fractionation by ultrafiltration.)

  9. G.S. Turner, G.A. Mills, J.L. Burnett, S. Amos, G.R. Fones, Evaluation of diffusive gradients in thin-films using a Diphonix® resin for monitoring dissolved uranium in natural waters, Anal. Chim. Acta 854 (2015) 78–85.
    (Shows that the DGT passive sampler with a Diphonix binding layer measures U well in freshwater, but has limitations in seawater.)

  10. J. Drozdzak, M. Leermakers, Y. Gao, V. Phrommavanh, M. Descostes, Novel speciation method based on Diffusive Gradients in Thin Films for in situ measurement of uranium in the vicinity of the former uranium mining sites, Environ. Pollut. 214 (2016) 114–123.
    (Develops DGT method for U using a binding layer of polyphenol impregnated anion exchange resin (PIWBA). Works well for all ionic strengths.)

  11. V. Smolikov, P. Pelcov, A. Ridoskov, M. Leermakers, Simultaneous determination of arsenic and uranium by the diffusive gradients in thin films technique using Lewatit FO 36: Optimization of elution protocol, Talanta 228 (2021) 122234.
    (Develops a DGT passive sampler method for U and As using a binding layer of Lewatit FO 36.)

  12. A. Martin, C. Landesmana, A. L. Pinay, C. Roux, J. Champion, P. Chardon, G. Montavon, Flow period influence on uranium and trace elements release in water from the waste rock pile of the former La Commanderie uranium mine (France), J. Env. Rad., 208 (2019) 106010.
    (Measures U using DGT passive samplers with a Chelex binding layer and compares to filtered spot samples)

  13. M. Christl, et al., The ETH Zurich AMS facilities: Performance parameters and reference materials, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 294, (2013) 29-38.
    (a comprehensive status report, including performance and operation parameters, of all three AMS systems operated by ETH Zurich.

  14. J. G. Panther, W. W. Bennett, P. R. Teasdale, D. T. Welsh, H. Zhao, DGT measurement of dissolved aluminum species in waters: comparing Chelex-100 and titanium dioxide-based adsorbents, Environmental science & technology, 46 (2012) 2267-2275.
    (Provides methodological details for measuring Al using a DGT passive sampler.)

  15. R. Dahlqvist, H. Zhang, J. Ingri, W. Davison, Performance of the diffusive gradients in thin films technique for measuring Ca and Mg in freshwater, Anal. Chim. Acta, 460 (2002) 247-256.
    (Provides performance characteristics and limitations for measuring Ca using a DGT passive sampler.)

  16. M. A. French, H. Zhang, J. M. Pates et al., Development and performance of the diffusive gradients in thin-films technique for the measurement of technetium-99 in seawater, Anal. Chem., 77: (2005), 135-139.
    (Provides performance characteristics for the development of this DGT passive sampler with a binding layer specific for Tc.)

  17. C. Murdock, M. Kelly, L-Y. Chang, W. Davison, H. Zhang, DGT as an in situ tool for measuring radiocesium in natural waters. Environ Sci Technol 35 (2001) 4530–4535.
    (Developed and used in freshwater DGT passive sampler with an AMP binding layer. Measurement was direct counting of gels on the gamma detector.)

  18. J. Gorny, A. Gourgiotis, F. Coppin, L. Février, H. Zhang, C. Simonucci, Better understanding and applications of ammonium 12-molybdophosphate-based diffusive gradient in thin film techniques for measuring Cs in waters, Environmental Science and Pollution Research 26 (2019) 1994–2006.
    (Demonstrated that AMP binding layer breaks down at longer times in basic or neutral waters.)