Environmental Chemistry Environmental Chemistry Society
Environmental problems - Chemical approaches
RESEARCH FRONT (Open Access)

Progress in understanding the use of diffusive gradients in thin films (DGT) – back to basics

William Davison A B and Hao Zhang A

A Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.

B Corresponding author. Email: w.davison@lancaster.ac.uk

Environmental Chemistry 9(1) 1-13 http://dx.doi.org/10.1071/EN11084
Submitted: 22 June 2011  Accepted: 13 September 2011   Published: 31 January 2012

Environmental context. It is now nearly 20 years since the introduction of the technique of diffusive gradients in thin films, which can provide information on solute concentrations and dynamics in sediments, soils and water. The interpretation of these measurements in terms of concentrations relies on simple equations and associated assumptions. This review examines how well they have stood the test of time.

Abstract. Diffusive gradients in thin films (DGT) is now widely used to measure a range of determinands in waters, soils and sediments. In most cases the mass accumulated is interpreted in terms of a labile form of the component being measured using a simple equation that applies to steady-state conditions. During the past decade several publications have revealed phenomena that question some of the assumptions necessary for use of the simple equation. This review systematically examines the available evidence relating to appropriate geometry, possible charge effects, binding of solutes and ligands to the diffusive gel and filter, the rate of reaction with the binding layer, the effects of solution complexation and kinetic limitation, necessary time for deployment and the measurement of nanoparticles. DGT emerges as a robust monitoring tool for labile components in solution. Although there is evidence, for some conditions, of binding of metals and, more moderately, humic substances to the diffusive gel and filter membrane, this is unlikely to affect DGT measurement in natural waters for deployment times exceeding a few days. Detailed speciation and kinetic studies require a more thorough interpretation of the mass accumulated by DGT. A coherent theory has emerged for relatively simple solutions, but systems with complex heterogeneous ligands, as is the case for natural waters, are challenging. The size discrimination of DGT is still poorly known. Systematic measurements with well characterised nanoparticles are required to define the distribution of pore sizes in the gels and to establish the contribution of natural colloids to the DGT measurement.


References

[1]  M. Schintu, B. Marras, L. Durante, P. Meloni, A. Contu, Macroalgae and DGT as indicators of available trace metals in marine coastal waters near a lead–zinc smelter. Environ. Monit. Assess. 2010, 167, 653.
Macroalgae and DGT as indicators of available trace metals in marine coastal waters near a lead–zinc smelter.CrossRef | 1:CAS:528:DC%2BC3cXos1Wqsbw%3D&md5=dfb0f8772f1e1aa40612f0c879ff24feCAS | open url image1

[2]  J. E. Sherwood, D. Barnett, N. W. Barnett, K. Dover, J. Howitt, H. Li, P. Kew, J. Mondon, Deployment of DGT units in marine waters to assess the environmental risk from a deep sea tailings outfall. Anal. Chim. Acta 2009, 652, 215.
Deployment of DGT units in marine waters to assess the environmental risk from a deep sea tailings outfall.CrossRef | 1:CAS:528:DC%2BD1MXhtF2htbvM&md5=8ac8a3fe5233b2677b3e474847ebb357CAS | open url image1

[3]  L. S. Balistrieri, R. G. Blank, Dissolved and labile concentrations of Cd, Cu, Pb, and Zn in the South Fork Coeur d’Alene River, Idaho: comparisons among chemical equilibrium models and implications for biotic ligand models. Appl. Geochem. 2008, 23, 3355.
Dissolved and labile concentrations of Cd, Cu, Pb, and Zn in the South Fork Coeur d’Alene River, Idaho: comparisons among chemical equilibrium models and implications for biotic ligand models.CrossRef | 1:CAS:528:DC%2BD1cXhsVWms73K&md5=0499bdee3c4b364183dd0a80f0436dddCAS | open url image1

[4]  M. Pesavento, G. Alberti, R. Biesuz, Analytical methods for determination of free metal ion concentration, labile species fraction and metal complexation capacity of environmental waters: a review. Anal. Chim. Acta 2009, 631, 129.
Analytical methods for determination of free metal ion concentration, labile species fraction and metal complexation capacity of environmental waters: a review.CrossRef | 1:CAS:528:DC%2BD1cXhsFWis73L&md5=df0202ebdfdb5983255588567842c580CAS | open url image1

[5]  M. V. Ardelan, E. Steinnes, Changes in mobility and solubility of the redox sensitive metals Fe, Mn and Co at the seawater-sediment interface following CO2 seepage. Biogeosciences 2010, 7, 569.
Changes in mobility and solubility of the redox sensitive metals Fe, Mn and Co at the seawater-sediment interface following CO2 seepage.CrossRef | 1:CAS:528:DC%2BC3cXltlCju7s%3D&md5=0b042049c5eee0efde06c7edc3725d59CAS | open url image1

[6]  O. Clarisse, B. Dimock, H. Hintelmann, E. P. H. Best, Predicting net mercury methylation in sediments using diffusive gradient in thin films measurements. Environ. Sci. Technol. 2011, 45, 1506.
Predicting net mercury methylation in sediments using diffusive gradient in thin films measurements.CrossRef | 1:CAS:528:DC%2BC3MXjvFCntg%3D%3D&md5=ba56d6f4c7adb347b062854864d995f9CAS | open url image1

[7]  R. M. Town, P. Chakraborty, H. P. van Leeuwen, Dynamic DGT speciation analysis and applicability to natural heterogeneous complexes. Environ. Chem. 2009, 6, 170.
Dynamic DGT speciation analysis and applicability to natural heterogeneous complexes.CrossRef | 1:CAS:528:DC%2BD1MXotVyqtrY%3D&md5=6fa1fd7e25cb6bcc1b0df5e917bf659eCAS | open url image1

[8]  K. W. Warnken, W. Davison, H. Zhang, J. Galceran, J. Puy, In situ measurements of metal complex exchange kinetics in freshwater. Environ. Sci. Technol. 2007, 41, 3179.
In situ measurements of metal complex exchange kinetics in freshwater.CrossRef | 1:CAS:528:DC%2BD2sXjsV2mur0%3D&md5=e131291b45e2e877a09c01c25768aa8dCAS | open url image1

[9]  R. Dahlqvist, K. Andersson, J. Ingri, T. Larsson, B. Stolpe, D. Turner, Temporal variations of colloidal carrier phases and associated trace elements in a boreal river. Geochim. Cosmochim. Acta 2007, 71, 5339.
Temporal variations of colloidal carrier phases and associated trace elements in a boreal river.CrossRef | 1:CAS:528:DC%2BD2sXht1GhurbF&md5=a24f2c73ddf7eaa21c737d282c7ab283CAS | open url image1

[10]  C. Oporto, E. Smolders, F. Degryse, L. Verheyen, C. Vandecasteele, DGT-measured fluxes explain the chloride-enhanced cadmium uptake by plants at low but not at high Cd supply. Plant Soil 2009, 318, 127.
DGT-measured fluxes explain the chloride-enhanced cadmium uptake by plants at low but not at high Cd supply.CrossRef | 1:CAS:528:DC%2BD1MXltVWrs7k%3D&md5=9cf90f149a342381ad1b8ec3d99d460cCAS | open url image1

[11]  H. Ernstberger, H. Zhang, A. Tye, S. Young, W. Davison, Desorption kinetics of Cd, Zn and Ni measured in intact soils by DGT. Environ. Sci. Technol. 2005, 39, 1591.
Desorption kinetics of Cd, Zn and Ni measured in intact soils by DGT.CrossRef | 1:CAS:528:DC%2BD2MXht1yhu7Y%3D&md5=d3024588c2935cb88695e4e59c36cea6CAS | open url image1

[12]  D. Ferreira, N. Tousset, C. Ridame, M. H. Tusseau-Vuillemin, More than inorganic copper is bioavailable to aquatic mosses at environmentally relevant concentrations. Environ. Toxicol. Chem. 2008, 27, 2108.
More than inorganic copper is bioavailable to aquatic mosses at environmentally relevant concentrations.CrossRef | 1:CAS:528:DC%2BD1cXht1SgurzM&md5=8e365e0c6591ca6b294c64f0a595456aCAS | open url image1

[13]  P. Bradac, R. Behra, L. Sigg, Accumulation of cadmium in periphyton under various freshwater speciation conditions. Environ. Sci. Technol. 2009, 43, 7291.
Accumulation of cadmium in periphyton under various freshwater speciation conditions.CrossRef | 1:CAS:528:DC%2BD1MXpslClt74%3D&md5=ae1b15e03c357b5a0844a9afc8f5c0f3CAS | open url image1

[14]  A. L. Pérez, K. A. Anderson, DGT estimates cadmium accumulation in wheat and potato from phosphate fertilizer applications. Sci. Total Environ. 2009, 407, 5096.
DGT estimates cadmium accumulation in wheat and potato from phosphate fertilizer applications.CrossRef | open url image1

[15]  I. Cattani, E. Capri, R. Boccelli, A. A. M. Del Re, Assessment of arsenic availability to roots in contaminated Tuscany soils by a diffusion gradient in thin films (DGT) method and uptake by Pteris vittata and Agrostis capillaris. Eur. J. Soil Sci. 2009, 60, 539.
Assessment of arsenic availability to roots in contaminated Tuscany soils by a diffusion gradient in thin films (DGT) method and uptake by Pteris vittata and Agrostis capillaris.CrossRef | 1:CAS:528:DC%2BD1MXhtVGis7zO&md5=80a6e9a0c29058a3f3734796f28cea0cCAS | open url image1

[16]  W. Davison, H. Zhang, In situ speciation measurements of trace components in natural waters using thin-film gels. Nature 1994, 367, 546.
In situ speciation measurements of trace components in natural waters using thin-film gels.CrossRef | 1:CAS:528:DyaK2cXhsVemtrc%3D&md5=a46668663a8de3d4c887158bbe7ebbcfCAS | open url image1

[17]  R. Dahlqvist, H. Zhang, W. Davison, J. Ingri, Performance of DGT (diffusive gradients in thin films) for measuring Ca and Mg in freshwater. Anal. Chim. Acta 2002, 460, 247.
Performance of DGT (diffusive gradients in thin films) for measuring Ca and Mg in freshwater.CrossRef | 1:CAS:528:DC%2BD38XjvF2ktrY%3D&md5=a16efe62bd59080e6f7ce35b421ff606CAS | open url image1

[18]  L. Chang, W. Davison, H. Zhang, M. Kelly, Performance characteristics for the measurement of Cs and Sr by diffusive gradients in thin films (DGT). Anal. Chim. Acta 1998, 368, 243.
Performance characteristics for the measurement of Cs and Sr by diffusive gradients in thin films (DGT).CrossRef | 1:CAS:528:DyaK1cXjtlOnsLY%3D&md5=2ad7730f7a06eea2fe23befc5b876997CAS | open url image1

[19]  H. Österlund, S. Chlot, M. Faarinen, A. Widerlund, I. Rodushkin, J. Ingri, D. C. Baxter, Simultaneous measurements of As, Mo, Sb, V and W using a ferrihydrite diffusive gradients in thin films (DGT) device. Anal. Chim. Acta 2010, 682, 59.
Simultaneous measurements of As, Mo, Sb, V and W using a ferrihydrite diffusive gradients in thin films (DGT) device.CrossRef | open url image1

[20]  S. M. Ding, D. Xu, Q. Sun, H. B. Yin, C. S. Zhang, Measurement of dissolved reactive phosphorus using the diffusive gradients in thin films technique with a high-capacity binding phase. Environ. Sci. Technol. 2010, 44, 8169.
Measurement of dissolved reactive phosphorus using the diffusive gradients in thin films technique with a high-capacity binding phase.CrossRef | 1:CAS:528:DC%2BC3cXht1eisrrI&md5=bcbd89763817c880dbc6dee2568505e2CAS | open url image1

[21]  C. R. DeVries, F. Wang, In situ two-dimensional high-resolution profiling of sulfide in sediment interstitial waters. Environ. Sci. Technol. 2003, 37, 792.
In situ two-dimensional high-resolution profiling of sulfide in sediment interstitial waters.CrossRef | 1:CAS:528:DC%2BD3sXksFChsA%3D%3D&md5=3e2b18ace8db43660c595b3e8b687a92CAS | open url image1

[22]  M. Gregusova, B. Docekal, New resin gel for uranium determination by diffusive gradient in thin films technique. Anal. Chim. Acta 2011, 684, 142.
New resin gel for uranium determination by diffusive gradient in thin films technique.CrossRef | 1:CAS:528:DC%2BC3cXhsF2msbnJ&md5=977c3619306e35db476b2837a400f315CAS | open url image1

[23]  M. Leermakers, Y. Gao, J. Navez, A. Poffijn, K. Croes, W. Baeyens, Radium analysis by sector field ICP-MS in combination with the Diffusive Gradients in Thin Films (DGT) technique. J. Anal. At. Spectrom. 2009, 24, 1115.
Radium analysis by sector field ICP-MS in combination with the Diffusive Gradients in Thin Films (DGT) technique.CrossRef | 1:CAS:528:DC%2BD1MXovVShtrc%3D&md5=7c9c1109d0fd4b1417272722fcebaeafCAS | open url image1

[24]  M. A. French, H. Zhang, J. M. Pates, S. E. Bryan, R. C. Wilson, Development and performance of the diffusive gradients in thin films technique for the measurement of technetium-99 in seawater. Anal. Chem. 2005, 77, 135.
Development and performance of the diffusive gradients in thin films technique for the measurement of technetium-99 in seawater.CrossRef | 1:CAS:528:DC%2BD2cXhtValsLfI&md5=5ad100e8eae4a751fbbf4f32f9948718CAS | open url image1

[25]  M. Harper, W. Davison, H. Zhang, W. Tych, Solid phase to solution kinetics in sediments and soils interpreted from DGT measured fluxes. Geochim. Cosmochim. Acta 1998, 62, 2757.
Solid phase to solution kinetics in sediments and soils interpreted from DGT measured fluxes.CrossRef | 1:CAS:528:DyaK1cXnslOjs7k%3D&md5=0ef15f4fdb491273c2335530aa317bc1CAS | open url image1

[26]  H. Zhang, W. Davison, Performance characteristics of the technique of diffusion gradients in thin-films (DGT) for the measurement of trace metals in aqueous solution. Anal. Chem. 1995, 67, 3391.
Performance characteristics of the technique of diffusion gradients in thin-films (DGT) for the measurement of trace metals in aqueous solution.CrossRef | 1:CAS:528:DyaK2MXnslKgtrc%3D&md5=bb9658e99f6d0c6ad7950f14c6e2b63dCAS | open url image1

[27]  M. R. Twiss, J. W. Moffett, Comparison of copper speciation in coastal marine waters measured using analytical voltammetry and diffusion gradient in thin-film techniques. Environ. Sci. Technol. 2002, 36, 1061.
Comparison of copper speciation in coastal marine waters measured using analytical voltammetry and diffusion gradient in thin-film techniques.CrossRef | 1:CAS:528:DC%2BD38XosV2ntA%3D%3D&md5=7321e3a505357603c8ab12955fa1fc52CAS | open url image1

[28]  H. Zhang, W. Davison, R. Gade, T. Kobayashi, In situ measurement of phosphate in natural waters using DGT. Anal. Chim. Acta 1998, 370, 29.
In situ measurement of phosphate in natural waters using DGT.CrossRef | 1:CAS:528:DyaK1cXjvFeqs78%3D&md5=0c26e2c1924ad9f97e675df442fd6b65CAS | open url image1

[29]  M. C. Alfaro-De la Torre, P. Y. Beaulieu, A. Tessier, In situ measurement of trace metals in lakewater using the dialysis and DGT techniques. Anal. Chim. Acta 2000, 418, 53.
In situ measurement of trace metals in lakewater using the dialysis and DGT techniques.CrossRef | open url image1

[30]  W. Davison, G. Fones, M. Harper, P. Teasdale, H. Zhang, Dialysis, DET and DGT: in situ diffusional techniques for studying water, sediments and soils, in In Situ Monitoring of Aquatic Systems: Chemical Analysis and Speciation (Eds J. Buffle, G. Horvai) 2000, pp. 495–570 (Wiley: New York).

[31]  H. Zhang, W. Davison, Diffusional characteristics of hydrogels used in DGT and DET techniques. Anal. Chim. Acta 1999, 398, 329.
Diffusional characteristics of hydrogels used in DGT and DET techniques.CrossRef | 1:CAS:528:DyaK1MXmvFeqtLk%3D&md5=4b258c91e60376e3c73b902e9e6083edCAS | open url image1

[32]  S. Scally, W. Davison, H. Zhang, Diffusion coefficients of metals and metal complexes in hydrogels used in diffusive gradients in thin films. Anal. Chim. Acta 2006, 558, 222.
Diffusion coefficients of metals and metal complexes in hydrogels used in diffusive gradients in thin films.CrossRef | 1:CAS:528:DC%2BD28XotFygtw%3D%3D&md5=0fb760c892c4443b28eebf4d1c1dea84CAS | open url image1

[33]  K. W. Warnken, H. Zhang, W. Davison, Accuracy of the diffusive gradients in thin-films technique: diffusive boundary layer and effective sampling area considerations. Anal. Chem. 2006, 78, 3780.
Accuracy of the diffusive gradients in thin-films technique: diffusive boundary layer and effective sampling area considerations.CrossRef | 1:CAS:528:DC%2BD28XktVSktrg%3D&md5=53fe9af778efe5a42da4d35f8f606ad9CAS | open url image1

[34]  A. W. Webb, M. J. Keough, Quantification of copper doses to settlement plates in the field using diffusive gradients in thin films. Sci. Total Environ. 2002, 298, 207.
Quantification of copper doses to settlement plates in the field using diffusive gradients in thin films.CrossRef | 1:CAS:528:DC%2BD38XnvVOhtrc%3D&md5=5bf1f7f96340362b5a18cd7c943ffc8eCAS | open url image1

[35]  J. L. Levy, H. Zhang, W. Davison, J. Puy, J. Galceran, Assessment of trace metal binding kinetics in dynamic techniques. Anal. Chim. Acta in press. open url image1

[36]  K. W. Warnken, W. Davison, H. Zhang, Interpretation of in situ speciation measurements of inorganic and organically complexed trace metals in freshwater by DGT. Environ. Sci. Technol. 2008, 42, 6903.
Interpretation of in situ speciation measurements of inorganic and organically complexed trace metals in freshwater by DGT.CrossRef | 1:CAS:528:DC%2BD1cXpvFSmurk%3D&md5=17f2f452321aa807afb8c92d86c87b8eCAS | open url image1

[37]  W. Davison, G. W. Grime, J. A. W. Morgan, K. Clarke, Distribution of dissolved iron in sediment pore waters at submillimetre resolution. Nature 1991, 352, 323.
Distribution of dissolved iron in sediment pore waters at submillimetre resolution.CrossRef | 1:CAS:528:DyaK3MXkvFyrtL4%3D&md5=9971de58e2fd78d7cadb51ad7ffa5b35CAS | open url image1

[38]  W. Davison, H. Zhang, G. W. Grime, Performance characteristics of gel probes used for measuring the chemistry of pore waters. Environ. Sci. Technol. 1994, 28, 1623.
Performance characteristics of gel probes used for measuring the chemistry of pore waters.CrossRef | 1:CAS:528:DyaK2cXltFOju7c%3D&md5=9d9f4d34dc5a0b93439a95a03166c0b1CAS | open url image1

[39]  M. D. Krom, P. Davison, H. Zhang, W. Davison, High resolution pore water sampling using a gel sampler: an innovative technique. Limnol. Oceanogr. 1994, 39, 1967.
High resolution pore water sampling using a gel sampler: an innovative technique.CrossRef | open url image1

[40]  A. Peters, H. Zhang, W. Davison, Investigation of the application of DGT devices for measurement of trace metals in low ionic strength freshwaters. Anal. Chim. Acta 2003, 478, 237.
Investigation of the application of DGT devices for measurement of trace metals in low ionic strength freshwaters.CrossRef | 1:CAS:528:DC%2BD3sXkvV2iug%3D%3D&md5=f2c7f73cbb1ad74c191ba7d0010907aeCAS | open url image1

[41]  K. Warnken, H. Zhang, W. Davison, Trace metal measurements in low ionic strength solutions by diffusive gradients in thin-films (DGT). Anal. Chem. 2005, 77, 5440.
Trace metal measurements in low ionic strength solutions by diffusive gradients in thin-films (DGT).CrossRef | 1:CAS:528:DC%2BD2MXms1Kntb4%3D&md5=5af5e2e974108f0e79d46fd6ecff929aCAS | open url image1

[42]  N. Fatin-Rouge, A. Milon, J. Buffle, R. R. Goulet, A. Tessier, Diffusion and partitioning of solutes in agarose hydrogels: the relative influence of electrostatic and specific interactions. J. Phys. Chem. B 2003, 107, 12 126.
Diffusion and partitioning of solutes in agarose hydrogels: the relative influence of electrostatic and specific interactions.CrossRef | 1:CAS:528:DC%2BD3sXnvFWkt74%3D&md5=2340102e504aa955b17afcdeb94b3757CAS | open url image1

[43]  L. P. Yezek, H. P. van Leeuwen, An electrokinetic characterization of low charge density cross-linked polyacrylamide gels. J. Colloid Intface Sci 2004, 278, 243.
An electrokinetic characterization of low charge density cross-linked polyacrylamide gels.CrossRef | 1:CAS:528:DC%2BD2cXms1Cmsbc%3D&md5=062c208c0bd2b962b859c10f7cb4b362CAS | open url image1

[44]  L. P. Yezek, H. P. van Leeuwen, Donnan effects in the steady-state diffusion of metal ions through charged thin films. Langmuir 2005, 21, 10 342.
Donnan effects in the steady-state diffusion of metal ions through charged thin films.CrossRef | 1:CAS:528:DC%2BD2MXhtVGqsrjJ&md5=67e4bf9f193db8a34eafc99a2909dc46CAS | open url image1

[45]  M. R. Sangi, M. J. Halstead, K. A. Hunter, Use of the diffusion gradient thin film method to measure trace metals in fresh waters at low ionic strength. Anal. Chim. Acta 2002, 456, 241.
Use of the diffusion gradient thin film method to measure trace metals in fresh waters at low ionic strength.CrossRef | 1:CAS:528:DC%2BD38XitFWgt70%3D&md5=3a32fa8018dd9a3c0cb58796a8750776CAS | open url image1

[46]  L. P. Yezek, L. R. van der Veeken, H. P. van Leeuwen, Donnan effects in metal speciation analysis by DET/DGT. Environ. Sci. Technol. 2008, 42, 9250.
Donnan effects in metal speciation analysis by DET/DGT.CrossRef | 1:CAS:528:DC%2BD1cXhtlKlsrjN&md5=7b7decf27e3b2b01be07180e19b166b4CAS | open url image1

[47]  L. R. van der Veeken, P. Chakraborti, H. P. van Leeuwen, Accumulation of humic acid in DET/DGT gels. Environ. Sci. Technol. 2010, 44, 4253.
Accumulation of humic acid in DET/DGT gels.CrossRef | 1:CAS:528:DC%2BC3cXlslWgsL8%3D&md5=c20cc011e02d1021351a648b754dce47CAS | open url image1

[48]  L. R. van der Veeken, H. P. van Leeuwen, DGT/DET gel partition features of humic acid/metal species. Environ. Sci. Technol. 2010, 44, 5523.
DGT/DET gel partition features of humic acid/metal species.CrossRef | 1:CAS:528:DC%2BC3cXnsFGitbw%3D&md5=f6e35ebe8aa4792c4ba69159520c8c82CAS | open url image1

[49]  J. Morford, L. Kalnejais, W. Martin, R. Francois, I.-M. Karle, Sampling marine porewaters for Mn, Fe, U, Re, and Mo: modifications on diffusional gradients in thin film gel probes. J. Exp. Mar. Biol. Ecol. 2003, 285–286, 85.
Sampling marine porewaters for Mn, Fe, U, Re, and Mo: modifications on diffusional gradients in thin film gel probes.CrossRef | open url image1

[50]  P. N. Williams, H. Zhang, W. Davison, A. A. Meharg, M. H. Sumon, G. J. Norton, H. Brammer, R. Islam, Organic matter–solid phase interactions are critical for predicting arsenic release and plant uptake in Bangladesh paddy soils. Environ. Sci. Technol. 2011, 45, 6080.
Organic matter–solid phase interactions are critical for predicting arsenic release and plant uptake in Bangladesh paddy soils.CrossRef | 1:CAS:528:DC%2BC3MXnvVKitLY%3D&md5=a00573b5d51ee3e399a0769d1210c6e9CAS | open url image1

[51]  H. P. Jarvie, R. J. G. Mortimer, E. J. Palmer-Felgate, K. St. Quinton, S. A. Harman, P. Carbo, Measurement of soluble reactive phosphorus concentration profiles and fluxes in river-bed sediments using DET gel probes. J. Hydrol. (Amst.) 2008, 350, 261.
Measurement of soluble reactive phosphorus concentration profiles and fluxes in river-bed sediments using DET gel probes.CrossRef | 1:CAS:528:DC%2BD1cXisFSru7g%3D&md5=6698d272f517c5c494db2c1b2eedf949CAS | open url image1

[52]  H. Docekalová, O. Clarisse, S. Salomon, M. Wartel, Use of constrained DET probe for a high resolution determination of metals and anions distribution in the sediment pore water. Talanta 2002, 57, 145.
Use of constrained DET probe for a high resolution determination of metals and anions distribution in the sediment pore water.CrossRef | open url image1

[53]  O. A. Garmo, W. Davison, H. Zhang, Interactions of trace metals with hydrogels and filter membranes used in DET and DGT techniques. Environ. Sci. Technol. 2008, 42, 5682.
Interactions of trace metals with hydrogels and filter membranes used in DET and DGT techniques.CrossRef | 1:CAS:528:DC%2BD1cXns1Wjsrg%3D&md5=3ca4684e1ceaa31de19b47cbd6cfac98CAS | open url image1

[54]  H. Docekalova, P. Divis, Application of diffusive gradient in thin films technique (DGT) to measurement of mercury in aquatic systems. Talanta 2005, 65, 1174.
Application of diffusive gradient in thin films technique (DGT) to measurement of mercury in aquatic systems.CrossRef | 1:CAS:528:DC%2BD2MXit1Cks7Y%3D&md5=26dc5dc546ac3ab5c50d0f2c7346f242CAS | open url image1

[55]  O. A. Garmo, W. Davison, H. Zhang, Effects of binding of metals to the hydrogel and filter membrane on the accuracy of the diffusive gradients in thin films technique. Anal. Chem. 2008, 80, 9220.
Effects of binding of metals to the hydrogel and filter membrane on the accuracy of the diffusive gradients in thin films technique.CrossRef | 1:CAS:528:DC%2BD1cXhtlWqu73E&md5=1c546ca69c3315c7f19c5c0ee2def7a0CAS | open url image1

[56]  M. H. Tusseau-Vuillemin, R. Gilbin, E. Bakkaus, J. Garrie, Performance of diffusion gradient in thin films to evaluate the toxic fraction of copper to Daphnia magna. Environ. Toxicol. Chem. 2004, 23, 2154.
Performance of diffusion gradient in thin films to evaluate the toxic fraction of copper to Daphnia magna.CrossRef | 1:CAS:528:DC%2BD2cXms1GhsLk%3D&md5=0053ef725a4b68843a52aa019959b910CAS | open url image1

[57]  E. Unsworth, H. Zhang, W. Davison, Use of DGT to measure cadmium speciation in solutions with synthetic and natural ligands: comparison with model predictions. Environ. Sci. Technol. 2005, 39, 624.
Use of DGT to measure cadmium speciation in solutions with synthetic and natural ligands: comparison with model predictions.CrossRef | 1:CAS:528:DC%2BD2cXhtVKit7fL&md5=b165eaf86aeac4d40d3cdcc7c2154e79CAS | open url image1

[58]  S. Mongin, R. Uribe, J. Puy, J. Cecilia, J. Galceran, H. Zhang, W. Davison, Key role of the resin layer thickness in the lability of complexes measured by DGT. Environ. Sci. Technol. 2011, 45, 4869.
Key role of the resin layer thickness in the lability of complexes measured by DGT.CrossRef | 1:CAS:528:DC%2BC3MXmtVCmsL0%3D&md5=d9e3bb0b37ba1e52c70d04b80b7901beCAS | open url image1

[59]  S. Scally, W. Davison, H. Zhang, Measurements of Pb speciation in synthetic solutions using DGT. Aust. J. Chem. 2004, 57, 925.
Measurements of Pb speciation in synthetic solutions using DGT.CrossRef | 1:CAS:528:DC%2BD2cXps1Sjsr0%3D&md5=651abd1874d418d7fa4d5b2f34ed529dCAS | open url image1

[60]  S. Denney, J. Sherwood, J. Leyden, In situ measurements of labile Cu, Cd and Mn in river waters using DGT. Sci. Total Environ. 1999, 239, 71.
In situ measurements of labile Cu, Cd and Mn in river waters using DGT.CrossRef | 1:CAS:528:DyaK1MXmtleiu74%3D&md5=1df940f3133c86465b80681813de457eCAS | open url image1

[61]  J. Gimpel, H. Zhang, W. Davison, In-situ trace metal speciation in lake surface waters using DGT, dialysis and filtration. Environ. Sci. Technol. 2003, 37, 138.
In-situ trace metal speciation in lake surface waters using DGT, dialysis and filtration.CrossRef | 1:CAS:528:DC%2BD38XptFCht7g%3D&md5=cc7585a65f4d9308b9886a20dacf180dCAS | open url image1

[62]  L. S. Balistrieri, R. R. Sear, N. M. Piatak, B. Paul, Assessing the concentration, speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine, Vermont, USA. Appl. Geochem. 2007, 22, 930.
Assessing the concentration, speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine, Vermont, USA.CrossRef | 1:CAS:528:DC%2BD2sXkvFGmtrw%3D&md5=492ec6dfbbac26d543dc775fcd4bd61eCAS | open url image1

[63]  E. R. Unsworth, K. W. Warnken, H. Zhang, W. Davison, F. Black, J. Buffle, J. Cao, R. Cleven, J. Galceran, P. Gunkel, E. Kalis, D. Kistler, H. P. Van Leeuwen, M. Michel, S. Noel, Y. Nur, N. Odzak, J. Puy, W. Van Riemsdijk, L. Sigg, E. Temminghoff, M.-L. Tercier-Waeber, S. Toepperwien, R. M. Town, L. Weng, H. Xue, Model predictions of metal speciation in freshwaters compared to measurements by in situ techniques. Environ. Sci. Technol. 2006, 40, 1942.
Model predictions of metal speciation in freshwaters compared to measurements by in situ techniques.CrossRef | 1:CAS:528:DC%2BD28XhtlSku7o%3D&md5=f1372c913c38a7567823d9613a4bb5f1CAS | open url image1

[64]  K. W. Warnken, A. J. Lawlor, S. Lofts, E. Tipping, W. Davison, H. Zhang, In situ speciation measurements of trace metals in headwater streams. Environ. Sci. Technol. 2009, 43, 7230.
In situ speciation measurements of trace metals in headwater streams.CrossRef | 1:CAS:528:DC%2BD1MXmsFGlsbw%3D&md5=3185a3f804945b6bbb28e10120bda836CAS | open url image1

[65]  S. Mason, R. Hamon, A. Nolan, H. Zhang, W. Davison, Performance of a mixed binding layer for measuring anions and cations in a single assay using the diffusive gradients in thin films technique. Anal. Chem. 2005, 77, 6339.
Performance of a mixed binding layer for measuring anions and cations in a single assay using the diffusive gradients in thin films technique.CrossRef | 1:CAS:528:DC%2BD2MXosVGhu78%3D&md5=deb1b9eca708204f3089ddb8c6728208CAS | open url image1

[66]  J. Luo, H. Zhang, J. Santner, W. Davison, Performance characteristics of diffusive gradients in thin films equipped with a binding gel layer containing precipitated ferrihydrite for measuring arsenic(V), selenium(VI), vanadium(V), and antimony(V). Anal. Chem. 2010, 82, 8903.
Performance characteristics of diffusive gradients in thin films equipped with a binding gel layer containing precipitated ferrihydrite for measuring arsenic(V), selenium(VI), vanadium(V), and antimony(V).CrossRef | 1:CAS:528:DC%2BC3cXht1OgsrvF&md5=12133eb1f69635f329296cdaaaa85d82CAS | open url image1

[67]  F. Degryse, E. Smolders, I. Oliver, H. Zhang, Relating soil solution Zn concentrations to diffusive gradients in thin films measurements in contaminated soils. Environ. Sci. Technol. 2003, 37, 3958.
Relating soil solution Zn concentrations to diffusive gradients in thin films measurements in contaminated soils.CrossRef | 1:CAS:528:DC%2BD3sXlvVyqtLc%3D&md5=9cc9185148b73faf0f63a5ad7ca57fa0CAS | open url image1

[68]  J. Søndergaard, In situ measurements of labile Al and Mn in acid mine drainage using diffusive gradients in thin films. Anal. Chem. 2007, 79, 6419.
In situ measurements of labile Al and Mn in acid mine drainage using diffusive gradients in thin films.CrossRef | open url image1

[69]  H. M. Conesa, R. Schulin, B. Nowack, Suitability of using diffusive gradients in thin films (DGT) to study metal bioavailability in mine tailings: possibilities and constraints. Environ. Sci. Technol. 2010, 17, 657.
| 1:CAS:528:DC%2BC3cXitVSisrc%3D&md5=d17caa716d62e7b12a6545a14de272cfCAS | open url image1

[70]  S. Tankere-Muller, H. Zhang, W. Davison, N. Finke, O. Larsen, H. Stahl, R. N. Glud, Fine scale remobilisation of Fe, Mn, Co, Ni, Cu and Cd in contaminated marine sediment. Mar. Chem. 2007, 106, 192.
Fine scale remobilisation of Fe, Mn, Co, Ni, Cu and Cd in contaminated marine sediment.CrossRef | 1:CAS:528:DC%2BD2sXovFSmur0%3D&md5=48c0a4b1875ed971546566329d4465a7CAS | open url image1

[71]  S. Mason, R. Hamon, H. Zhang, J. Anderson, Investigating chemical constraints to the measurement of phosphorus in soils using diffusive gradients in thin films (DGT) and resin methods. Talanta 2008, 74, 779.
Investigating chemical constraints to the measurement of phosphorus in soils using diffusive gradients in thin films (DGT) and resin methods.CrossRef | 1:CAS:528:DC%2BD1cXjtV2msA%3D%3D&md5=0a2269acd299eb40d7a44a4193c03f61CAS | open url image1

[72]  J. D. Panther, P. R. Teasdale, W. M. Bennett, D. T. Welsh, H. J. Zhao, Titanium dioxide-based DGT technique for in situ measurement of dissolved reactive phosphorus in fresh and marine waters. Environ. Sci. Technol. 2010, 44, 9419.
Titanium dioxide-based DGT technique for in situ measurement of dissolved reactive phosphorus in fresh and marine waters.CrossRef | 1:CAS:528:DC%2BC3cXhsVGkt7jP&md5=16a8eca49566fc0b0d55119f89f1cf06CAS | open url image1

[73]  N. J. Lehto, W. Davison, H. Zhang, W. Tych, An evaluation of DGT performance using a dynamic numerical model. Environ. Sci. Technol. 2006, 40, 6368.
An evaluation of DGT performance using a dynamic numerical model.CrossRef | 1:CAS:528:DC%2BD28XptFahurg%3D&md5=ac36a76424fbbfd5f5bf7555cfaddb8dCAS | open url image1

[74]  H. Zhang, W. Davison, Direct in situ measurements of labile inorganic and organically bound metal species in synthetic solutions and natural waters using diffusive gradients in thin films. Anal. Chem. 2000, 72, 4447.
Direct in situ measurements of labile inorganic and organically bound metal species in synthetic solutions and natural waters using diffusive gradients in thin films.CrossRef | 1:CAS:528:DC%2BD3cXls1Oku70%3D&md5=d413eae3075abca5abe0b85b9434b2c0CAS | open url image1

[75]  H. Zhang, Competition effects on the binding of Ni, Zn and Cu by organic matter. Environ. Sci. Technol. 2004, 38, 1421.
Competition effects on the binding of Ni, Zn and Cu by organic matter.CrossRef | 1:CAS:528:DC%2BD2cXmtlWguw%3D%3D&md5=19fedd8f10c863500904247ff6e7b2ccCAS | open url image1

[76]  E. Tipping, Cation Binding by Humic Substances 2002 (Cambridge University Press: Cambridge, UK).

[77]  Z. Zhang, J. Buffle, Metal flux and dynamic speciation at (bio)interfaces. Part V: the role of simple, fulvic and aggregate complexes on Pb flux in freshwater ligand mixtures, computed at planar consuming interfaces. Geochim. Cosmochim. Acta 2009, 73, 1223.
Metal flux and dynamic speciation at (bio)interfaces. Part V: the role of simple, fulvic and aggregate complexes on Pb flux in freshwater ligand mixtures, computed at planar consuming interfaces.CrossRef | 1:CAS:528:DC%2BD1MXhvFajtbg%3D&md5=9a0c456f78ed8cb55f746fc4a736b0c7CAS | open url image1

[78]  Z. Zhang, J. Buffle, Metal flux and dynamic speciation at (bio)interfaces. Part VI: the roles of simple, fulvic and aggregate complexes on computed metal flux in freshwater ligand mixtures; comparison of Pb, Zn and Ni at planar and microspherical interfaces. Geochim. Cosmochim. Acta 2009, 73, 1236.
Metal flux and dynamic speciation at (bio)interfaces. Part VI: the roles of simple, fulvic and aggregate complexes on computed metal flux in freshwater ligand mixtures; comparison of Pb, Zn and Ni at planar and microspherical interfaces.CrossRef | 1:CAS:528:DC%2BD1MXhvFajtbk%3D&md5=437bf93dad3ebc2c3198587d6860a0f9CAS | open url image1

[79]  S. Scally, W. Davison, H. Zhang, In situ measurements of dissociation kinetics and labilities of metal complexes in synthetic solutions using DGT. Environ. Sci. Technol. 2003, 37, 1379.
In situ measurements of dissociation kinetics and labilities of metal complexes in synthetic solutions using DGT.CrossRef | 1:CAS:528:DC%2BD3sXhsFWjt7s%3D&md5=9f11e49a0e4e65820121c621096d0651CAS | open url image1

[80]  J. Salvador, J. Puy, J. Cecilia, J. Galceran, Lability of complexes in steady state finite planar diffusion. J. Electroanal. Chem. 2006, 588, 303.
Lability of complexes in steady state finite planar diffusion.CrossRef | 1:CAS:528:DC%2BD28XitVSmuro%3D&md5=fbac2acc7dcb35510b7a0d744f9b1776CAS | open url image1

[81]  R. Uribe, S. Mongin, J. Puy, J. Cecilia, J. Galceran, H. Zhang, W. Davison, Contribution of partially labile complexes to the DGT metal flux. Environ. Sci. Technol. 2011, 45, 5317.
Contribution of partially labile complexes to the DGT metal flux.CrossRef | 1:CAS:528:DC%2BC3MXmsVWlsLs%3D&md5=6cc3cab7c0bd2fd208333710ea6dfa92CAS | open url image1

[82]  M. H. Tusseau-Vuillemin, R. Gilbin, M. A. Taillefert, A dynamic numerical model to characterise labile metal complexes collected with diffusive gradients in thin-films devices. Environ. Sci. Technol. 2003, 37, 1645.
A dynamic numerical model to characterise labile metal complexes collected with diffusive gradients in thin-films devices.CrossRef | 1:CAS:528:DC%2BD3sXitFGnu7o%3D&md5=0a17a4000a44db6a02e17869296668ecCAS | open url image1

[83]  O. A. Garmo, N. J. Lehto, H. Zhang, W. Davison, O. Røyset, E. Steinnes, Dynamic aspects of DGT as demonstrated by experiments with lanthanide complexes of a multidentate ligand. Environ. Sci. Technol. 2006, 40, 4754.
Dynamic aspects of DGT as demonstrated by experiments with lanthanide complexes of a multidentate ligand.CrossRef | 1:CAS:528:DC%2BD28XmsVaisrs%3D&md5=b03212374de59448303dc3ecc8b1efefCAS | open url image1

[84]  H. P. van Leeuwen, Dynamic aspects of in situ speciation processes and techniques, in In Situ Monitoring of Aquatic Systems: Chemical Analysis and Speciation (Eds J. Buffle, G. Horvai) 2000, pp. 525–528 (Wiley: New York).

[85]  H. P. Van Leeuwen, Steady-state DGT fluxes of nanoparticulate metal complexes. Environ. Chem. 2011, 8, 525.
| 1:CAS:528:DC%2BC3MXhtlykt73F&md5=74244b53ebf1888b15500aab2ad17fe1CAS | open url image1

[86]  B. Nowack, S. Koehler, R. Schulin, Use of diffusive gradients in thin films (DGT) in undisturbed field soils. Environ. Sci. Technol. 2004, 38, 1133.
Use of diffusive gradients in thin films (DGT) in undisturbed field soils.CrossRef | 1:CAS:528:DC%2BD2cXksFOisg%3D%3D&md5=53fb00f1961c427bc299b25f1e98bd16CAS | open url image1

[87]  N. Fatin-Rouge, K. Starchev, J. Buffle, Size effects on diffusion processes within agarose gels. Biophys. J. 2004, 86, 2710.
Size effects on diffusion processes within agarose gels.CrossRef | 1:CAS:528:DC%2BD2cXjvVyjtLs%3D&md5=5e7661bbdd71ce0d6adf5c7914a72c14CAS | open url image1

[88]  P. L. R. van der Veeken, J. P. Pinheiro, H. P. van Leeuwen, Metal speciation by DGT/DET in colloidal complex systems. Environ. Sci. Technol. 2008, 42, 8835.
Metal speciation by DGT/DET in colloidal complex systems.CrossRef | 1:CAS:528:DC%2BD1cXhtlSnu7zE&md5=10bda423c06978d7e223337d72083568CAS | open url image1

[89]  J. Buffle, Complexation Reactions in Aquatic Systems; an Analytical Approach 1988 (Ellis Horwood: Chichester, UK).

[90]  J. R. Lead, J. Hamilton-Taylor, N. Nesketh, M. N. Jones, A. E. Wilkinson, E. Tipping, A comparative study of proton and alkaline–earth metal-binding by humic substances. Anal. Chim. Acta 1994, 294, 319.
A comparative study of proton and alkaline–earth metal-binding by humic substances.CrossRef | 1:CAS:528:DyaK2cXlslyksr8%3D&md5=83f6af6a5de8759ce38854a1b482e86aCAS | open url image1

[91]  J. Forsberg, R. Dahlqvist, J. Gelting-Nystrom, J. Ingri, Trace metal speciation in brackish water using diffusive gradients in thin films and ultrafiltration: comparison of techniques. Environ. Sci. Technol. 2006, 40, 3901.
Trace metal speciation in brackish water using diffusive gradients in thin films and ultrafiltration: comparison of techniques.CrossRef | 1:CAS:528:DC%2BD28XksFKku7s%3D&md5=3357ccad93020bcb21718c51b200d0f4CAS | open url image1

[92]  J. Labille, N. Fatin-Rouge, J. Buffle, Local and average diffusion of nanosolutes in agarose gel: the effect of the gel–solution interface structure. Langmuir 2007, 23, 2083.
Local and average diffusion of nanosolutes in agarose gel: the effect of the gel–solution interface structure.CrossRef | 1:CAS:528:DC%2BD28XhtlCqtrrJ&md5=a749eb20d543dbbdd3903e86312b26e2CAS | open url image1


Full Text PDF (484 KB) Export Citation