Accreditation and Quality Assurance

, Volume 16, Issue 4–5, pp 215–223 | Cite as

Trace element complexation by humic substances: issues related to quality assurance

  • Montserrat FilellaEmail author
  • Wolfgang Hummel
General Paper


Despite the amount of data available and the effort that has been put into studying the binding of trace elements by humic substances, there is still a significant amount of uncertainty surrounding the validity and applicability of the existing values in solving particular problems in the environmental, toxicity and industrial fields. This paper discusses the problems associated with the characterisation of humic binding and proposes a general approach for quality assessing trace element-humic substances complexation data, which includes the normalisation of raw experimental data prior to any data treatment (modelling).


Humic substances Metal binding Metal complexation Quality assurance Aquatic chemistry 


  1. 1.
    Filella M (2007) Colloidal properties of submicron particles in natural waters. In: Wilkinson KW, Lead J (eds) Environmental colloids and particles. Behaviour, separation and characterisation, IUPAC-Wiley, pp 17–93Google Scholar
  2. 2. Last accessed 18 Oct 2010
  3. 3.
    Filella M (2009) Freshwaters: which NOM matters? Environ Chem Lett 7:21–35CrossRefGoogle Scholar
  4. 4.
    Tipping E (2002) Cation binding by humic substances. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  5. 5.
    Koopal LK, Saito T, Pinheiro JP, van Riemsdijk WH (2005) Ion binding to natural organic matter: general considerations and the NICA-Donnan model. Coll Surf A 265:40–54CrossRefGoogle Scholar
  6. 6.
    Humic-Metal Binding Constants Database, IUPAC project 2008-025-1-500Google Scholar
  7. 7.
    Coleman NT, McClung AC, Moore DP (1956) Formation constants for Cu(II)-peat complexes. Science 123:330–331CrossRefGoogle Scholar
  8. 8.
    Himes FL, Barber SA (1957) Chelating ability of soil organic matter. Soil Sci Soc Am Proc 21:368–373CrossRefGoogle Scholar
  9. 9.
  10. 10.
  11. 11.
  12. 12.
    Filella M, May PM (2010) Chemical modelling of multicomponent mixtures: why quality assurance encompasses more than pure equilibrium data quality assessment and how it can be achieved. Accred Qual Assur. doi: 10.1007/s00769-010-0701-x
  13. 13.
    Ritchie JD, Perdue EM (2003) Proton-binding study of standard and reference fulvic acids, humic acids, and natural organic matter. Geochim Cosmochim Acta 67:85–96CrossRefGoogle Scholar
  14. 14.
    Thurman EM (1985) Organic geochemistry of natural waters. Martinus Nijhoff/Dr W. Junk Publishers, DordrechtGoogle Scholar
  15. 15.
    Duffus JF (2002) “Heavy metals”—a meaningless term? Pure Appl Chem 74:793–807CrossRefGoogle Scholar
  16. 16.
    Filella M, Town RM, Buffle J (2002) Speciation in freshwaters. In: Ure AM, Davidson CM (eds) Chemical speciation in the environment, 2nd edn. Blackwell, Oxford, pp 188–236CrossRefGoogle Scholar
  17. 17.
    Gamble DS, Underdown AW, Langford CH (1980) Copper(II) titration of fulvic acid ligand sites with theoretical, potentiometric, and spectrophotometric analysis. Anal Chem 52:1901–1908CrossRefGoogle Scholar
  18. 18.
    Buffle J, Altmann RS (1987) Interpretation of metal complexation by heterogeneous complexants. In: Stumm W (ed) Aquatic surface chemistry: chemical processes at the particle-water interface. Wiley, New York, pp 351–383Google Scholar
  19. 19.
    Buffle J (1988) Complexation reactions in aquatic systems. An analytical approach. Ellis Horwood, ChichesterGoogle Scholar
  20. 20.
    Hummel W, Glaus MA, Van Loon LR (1999) Complexation of radionuclides with humic substance: the metal concentration effect. Radiochim Acta 84:111–114Google Scholar
  21. 21.
    Altmann RS, Buffle J (1988) The use of differential equilibrium functions for interpretation of metal binding in complex ligand systems: its relation to site occupation and site affinity distributions. Geochim Cosmochim Acta 52:1505–1519CrossRefGoogle Scholar
  22. 22.
    Filella M (2008) NOM site binding heterogeneity in natural waters: discrete approaches. J Mol Liquids 143:42–51CrossRefGoogle Scholar
  23. 23.
    Buffle J, Filella M (1995) Physico-chemical heterogeneity of natural complexants: clarification. Anal Chim Acta 313:144–150CrossRefGoogle Scholar
  24. 24.
    Hummel W (1997) Binding models for humic substances. In: Grenthe I, Puigdomenech I (eds) Modelling in aquatic chemistry. Nuclear Energy Agency, Paris, pp 153–206Google Scholar
  25. 25.
    Oreskes N, Shrader-Frechette K, Belitz K (1994) Verification, validation, and confirmation of numerical models in the Earth Sciences. Science 263:641–645CrossRefGoogle Scholar
  26. 26.
    Filella M (2010) Quantifying ‘humics’ in freshwaters: purpose and methods. Chem Ecol 26:177–186Google Scholar
  27. 27.
    Nordstrom DK (1993) EOS Trans Am Geophys Union Suppl April 20 326Google Scholar
  28. 28.
    Tipping E, Hurley MA (1992) A unifying model of cation binding by humic substances. Geochim Cosmochim Acta 56:3627–3641CrossRefGoogle Scholar
  29. 29.
    Hummel W, Glaus MA, Van Loon LR (2000) Trace metal-humate interactions. II. The “conservative roof” model and its application. Appl Geochem 15:975–1001CrossRefGoogle Scholar
  30. 30.
  31. 31.
    Buffle J, Altmann RS, Filella M, Tessier A (1990) Complexation by natural heterogeneous compounds: site occupation distribution functions, a normalized description of metal complexation. Geochim Cosmochim Acta 54:1535–1553CrossRefGoogle Scholar
  32. 32.
    Buffle J, Altmann RS, Filella M (1990) The effect of physico-chemical heterogeneity of natural complexants. II. The buffering action and role of their background sites. Anal Chim Acta 232:225–237CrossRefGoogle Scholar
  33. 33.
    Benedetti MF, Milne CJ, Kinniburgh DG, van Riemsdijk WH, Koopal LK (1995) Metal ion binding to humic substances: application of the non-ideal competitive adsorption model. Environ Sci Technol 29:446–457CrossRefGoogle Scholar
  34. 34.
    Carlsen L, Bo P, Larsen G (1984) Radionuclide-humic acid interactions studied by dialysis. In: Barney GS, Navratil JD, Schulz WW (eds) Geochemical behavior of disposed radioactive waste. American Chemical Society, Washington, DC, pp 167–180CrossRefGoogle Scholar
  35. 35.
    Caceci MS (1985) The interaction of humic acid with europium(III). Complexation strength as a function of load and pH. Radiochim Acta 39:51–56Google Scholar
  36. 36.
    Bidoglio G, Grenthe I, Qi P, Robouch P, Omenetto N (1991) Complexation of europium and terbium with fulvic acids as studied by time-resolved laser-induced fluorescence. Talanta 38:999–1008CrossRefGoogle Scholar
  37. 37.
    Glaus MA, Hummel W, Van Loon LR (1997) Experimental determination and modeling of trace metal-humate interactions: a pragmatic approach for applications in groundwater. PSI Report No. 97-13, Paul Scherrer Institute, Villigen, Switzerland. Also published as Nagra Technical Report NTB 97-03, Nagra, Wettingen, SwitzerlandGoogle Scholar
  38. 38.
    Kim JI, Buckau G, Bryant E, Klenze R (1989) Complexation of americium(III) with humic acid. Radiochim Acta 48:135–143Google Scholar
  39. 39.
    Kim JI, Rhee DS, Wimmer H, Buckau G, Klenze R (1993) Complexation of trivalent actinide ions (Am3+, Cm3+) with humic acid: a comparison of different experimental methods. Radiochim Acta 62:35–43Google Scholar
  40. 40.
    Moulin V, Tits J, Moulin C, Decambox P, Mauchien P, de Ruty O (1992) Complexation behaviour of humic substances towards actinides and lanthanides studied by time-resolved laser-induced spectrofluorometry. Radiochim Acta 58/59:121–128Google Scholar
  41. 41.
    Ellison SLR, Rosslein M, Williams A (eds) (2000) Quantifying uncertainty in analytical measurement. 2 edn. EURACHEM/CITAC Guide CG 4Google Scholar
  42. 42.
    Braibanti A, Ostacoli G, Paoletti P, Pettit LD, Sammartano S (1987) Recommended procedure for testing the potentiometric apparatus and technique for the pH-metric measurement of metal-complex equilibrium constants. Pure Appl Chem 59:1721–1728CrossRefGoogle Scholar
  43. 43.
    Tuck DG (1989) A proposal for the use of a standard format for the publication of stability constant measurements. Pure Appl Chem 61:1161–1163CrossRefGoogle Scholar
  44. 44.
    Filella M, May PM (2005) Reflections on the calculation and publication of potentiometrically determined formation constants. Talanta 65:1221–1225CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Institute F.-A. ForelUniversity of GenevaVersoixSwitzerland
  2. 2.SCHEMARameldangeLuxembourg
  3. 3.Laboratory for Waste ManagementPaul Scherrer InstituteVilligenSwitzerland

Personalised recommendations