Two commonly applied single extractions procedures, namely extractions with ammonium-EDTA and acetic acid, were evaluated based on the analysis of 72 samples from alluvial sediments. For most trace elements (Cu, Zn, Cd, Ni, As, and Pb), a significant linear relationship could be established between their ammonium-EDTA or acetic acid extractable concentrations and their total concentrations, the organic carbon content, pH, and Fe , Al, and/or Ca content in the sediments. The scientific understanding of trace element partitioning in the complex soil-water system with these simple models is rather limited, but they offer the opportunity to use data from single extractions in a more comprehensive way. Despite the fact that these extractions cannot directly be related to the bioavailability of elements, they can provide input data for use in risk assessment models. Additionally, they also offer possibilities to perform a fast screening of the mobilizable pool of elements in soils and/or sediments. 1. Introduction The contamination of soils and sediments is widespread and is a potential threat for the environment in the short and long term. The impact of trace elements in soils and sediments on the environment depends on their speciation, mobility, and bioavailability. Over the past decades, the term “heavy metals” has increasingly been used, without any consistency to denote trace element contamination of environmental media. An overview of the use of the term “heavy metals” in scientific dictionaries and relevant literature can be found in Duffus [1]. Since “heavy metals” is a poor scientific term and many alternatives exit [2], we will use the term “trace elements” in the present study to refer to As, Cd, Cu, Cr, Ni, Pb, and Zn. Talking about trace metals would be incorrect because arsenic is actually a metalloid. Before discussing the different methods for determination of “trace element” availability in soils and/or sediments and before addressing the pros and cons of single and sequential extraction procedures, the difference between soils and sediments will be clarified, as well as the terminology used throughout this paper. 1.1. Soils versus Sediments Soils and sediments are different matrixes from many viewpoints, especially under the environmental context. “Soil” can be defined as a “three-dimensional body with properties that reflect the impact of climate, vegetation, fauna, and topography on soils parent material over a variable time span. Soils are still in a process of change. As a result of “soil formation” or “pedogenesis,” soil profiles show
References
[1]
J. H. Duffus, “Heavy metals—a meaningless term?” Pure and Applied Chemistry, vol. 74, no. 5, pp. 793–807, 2002.
[2]
M. E. Hodson, “Heavy metals—geochemical bogey men?” Environmental Pollution, vol. 129, no. 3, pp. 341–343, 2004.
[3]
P. M. Driessen and R. Dudal, The Major Soils of the World, Lecture Notes on Their Geography, Formation, Proiperties and Use, Agricultural University of Wageningen and Katholieke Universiteit Leuven, 1991.
IUSS Working Group WRB, “World reference base for soil resources A framework for international classification, correlation and communication,” World Soil Resources Reports 103, FAO, Rome, Italy, 2006.
[6]
A. C. Scheinost, R. Kretzschmar, S. Pfister, and D. R. Roberts, “Combining selective sequential extractions, X-ray absorption spectroscopy, and principal component analysis for quantitative zinc speciation in soil,” Environmental Science and Technology, vol. 36, no. 23, pp. 5021–5028, 2002.
[7]
W. J. G. M. Peijnenburg, M. Zablotskaja, and M. G. Vijver, “Monitoring metals in terrestrial environments within a bioavailability framework and a focus on soil extraction,” Ecotoxicology and Environmental Safety, vol. 67, no. 2, pp. 163–179, 2007.
[8]
A. L. Nolan, M. J. McLaughlin, and S. D. Mason, “Chemical speciation of Zn, Cd, Cu, and Pb in pore waters of agricultural and contaminated soils using donnan dialysis,” Environmental Science and Technology, vol. 37, no. 1, pp. 90–98, 2003.
[9]
J. L. Roulier, S. Belaud, and M. Coquery, “Comparison of dynamic mobilization of Co, Cd and Pb in sediments using DGT and metal mobility assessed by sequential extraction,” Chemosphere, vol. 79, no. 8, pp. 839–843, 2010.
[10]
M. Koster, L. Reijnders, N. R. Van Oost, and W. J. G. M. Peijnenburg, “Comparison of the method of diffusive gels in thin films with conventional extraction techniques for evaluating zinc accumulation in plants and isopods,” Environmental Pollution, vol. 133, no. 1, pp. 103–116, 2005.
[11]
H. Vandenhove, K. Antunes, J. Wannijn, L. Duquène, and M. Van Hees, “Method of diffusive gradients in thin films (DGT) compared with other soil testing methods to predict uranium phytoavailability,” Science of the Total Environment, vol. 373, no. 2-3, pp. 542–555, 2007.
[12]
O. Mojsilovic, R. G. McLaren, and L. M. Condron, “Modelling arsenic toxicity in wheat: simultaneous application of diffusive gradients in thin films to arsenic and phosphorus in soil,” Environmental Pollution, vol. 159, no. 10, pp. 2996–3002, 2011.
[13]
P. M. V. Nirel and F. M. M. Morel, “Pitfalls of sequential extractions,” Water Research, vol. 24, no. 8, pp. 1055–1056, 1990.
[14]
I. Maiz, M. V. Esnaola, and E. Millán, “Evaluation of heavy metal availability in contaminated soils by a short sequential extraction procedure,” Science of the Total Environment, vol. 206, no. 2-3, pp. 107–115, 1997.
[15]
J. L. Gómez Ariza, I. Giráldez, D. Sánchez-Rodas, and E. Morales, “Comparison of the feasibility of three extraction procedures for trace metal partitioning in sediments from south-west Spain,” Science of the Total Environment, vol. 246, no. 2-3, pp. 271–283, 2000.
[16]
P. S. Rendell, G. E. Batley, and A. J. Cameron, “Adsorption as a control of metal concentrations in sediment extracts,” Environmental Science and Technology, vol. 14, no. 3, pp. 314–318, 1980.
[17]
J. L. Howard and W. J. Vandenbrink, “Sequential extraction analysis of heavy metals in sediments of variable composition using nitrilotriacetic acid to counteract resorption,” Environmental Pollution, vol. 106, no. 3, pp. 285–292, 1999.
[18]
A. Tessier and P. G. C. Campbell, “Comments on the testing of the accuracy of an extraction procedure for determining the partitioning of trace metals in sediments,” Analytical Chemistry, vol. 60, no. 14, pp. 1475–1476, 1988.
[19]
A. Tessier and P. G. C. Campbell, “Comment on 'Pitfalls of sequential extractions' by P.M.V. Nirel and F.M.M. Morel,” Water Research, vol. 24, pp. 1055–1056, 1991.
[20]
E. Tipping, N. B. Hetherington, J. Hilton, D. W. Thompson, E. Bowles, and J. Hamilton-Taylor, “Arrtifacts in the use of chemical extraction to determine distributions of metals between oxides of manganese and iron,” Analytical Chemistry, vol. 57, pp. 1944–1946, 1985.
[21]
K. A. Gruebel, J. A. Davis, and J. O. Leckie, “The feasibility of using sequential extraction techniques for arsenic and selenium in soils and sediments,” Soil Science Society of America Journal, vol. 52, no. 2, pp. 390–397, 1988.
[22]
R. T. Dhoum and G. J. Evans, “Evaluation of uranium and arsenic retention by soil from a low level radioactive waste management site using sequential extraction,” Applied Geochemistry, vol. 13, no. 4, pp. 415–420, 1998.
[23]
M. J. La Force and S. Fendorf, “Solid-phase iron characterization during common selective sequential extractions,” Soil Science Society of America Journal, vol. 64, no. 5, pp. 1608–1615, 2000.
[24]
X.-Q. Shan and B. Chen, “Evaluation of sequential extraction for speciation of trace metals in model soil containing natural minerals and humic acid,” Analytical Chemistry, vol. 65, no. 6, pp. 802–807, 1993.
[25]
J. L. Gómez Ariza, I. Giráldez, D. Sánchez-Rodas, and E. Morales, “Selectivity assessment of a sequential extraction procedure for metal mobility characterization using model phases,” Talanta, vol. 52, no. 3, pp. 545–554, 2000.
[26]
S. Van Herreweghe, R. Swennen, C. Vandecasteele, and V. Cappuyns, “Solid phase speciation of arsenic by sequential extraction in standard reference materials and industrially contaminated soil samples,” Environmental Pollution, vol. 122, no. 3, pp. 323–342, 2003.
[27]
P. Quevauviller, “Operationally defined extraction procedures for soil and sediment analysis I. Standardization,” Trends in Analytical Chemistry, vol. 17, no. 5, pp. 289–298, 1998.
[28]
A. Ure, P. Quevauviller, H. Munteau, and B. Griepink, “Improvements in the determination of extractable contents of trace metals in soils and sediments prior to certification,” Tech. Rep., Community Bureau of reference, Commission of the European Communities, 1993.
[29]
G. Rauret, J. F. López-Sánchez, A. Sahuquillo et al., “Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials,” Journal of Environmental Monitoring, vol. 1, no. 1, pp. 57–61, 1999.
[30]
A. Sahuquillo, J. F. López-Sánchez, R. Rubio et al., “Use of a certified reference material for extractable trace metals to assess sources of uncertainty in the BCR three-stage sequential extraction procedure,” Analytica Chimica Acta, vol. 382, no. 3, pp. 317–327, 1999.
[31]
S. K. Gupta, M. K. Vollmer, and R. Krebs, “The importance of mobile, mobilisable and pseudo total heavy metal fractions in soil for three-level risk assessment and risk management,” Science of the Total Environment, vol. 178, pp. 11–20, 1996.
[32]
W. P. Miller, D. C. Martens, L. W. Zelazny, and E. T. Kornegay, “Forms of solid phase copper in copper-enriched swine manure,” Journal of Environmental Quality, vol. 15, no. 1, pp. 69–72, 1986.
[33]
O. K. Borggaard, “Selective extraction of amorphous iron oxides by EDTA from a Danish sandy loam,” Journal of Soil Science, vol. 30, pp. 727–734, 1979.
[34]
B. Nowack and L. Sigg, “Dissolution of Fe(III)(hydr) oxides by metal-EDTA complexes,” Geochimica et Cosmochimica Acta, vol. 61, no. 5, pp. 951–963, 1997.
[35]
M. A. M. Kedziorek and A. C. M. Bourg, “Solubilization of lead and cadmium during the percolation of EDTA through a soil polluted by smelting activities,” Journal of Contaminant Hydrology, vol. 40, no. 4, pp. 381–392, 2000.
[36]
L. Madrid and E. Díaz-Barrientos, “Release of metals from homogeneous soil columns by wastewater from an agricultural industry,” Environmental Pollution, vol. 101, no. 1, pp. 43–48, 1998.
[37]
B. Sun, F. J. Zhao, E. Lombi, and S. P. McGrath, “Leaching of heavy metals from contaminated soils using EDTA,” Environmental Pollution, vol. 113, no. 2, pp. 111–120, 2001.
[38]
Z. Zou, R. Qiu, W. Zhang et al., “The study of operating variables in soil washing with EDTA,” Environmental Pollution, vol. 157, no. 1, pp. 229–236, 2009.
[39]
N. Papassiopi, S. Tambouris, and A. Kontopoulos, “Removal of heavy metals from calcareous contaminated soils by EDTA leaching,” Water, Air, and Soil Pollution, vol. 109, no. 1–4, pp. 1–15, 1999.
[40]
N. Fin？gar and D. Le？tan, “Multi-step leaching of Pb and Zn contaminated soils with EDTA,” Chemosphere, vol. 66, no. 5, pp. 824–832, 2007.
[41]
R. S. Tejowulan and W. H. Hendershot, “Removal of trace metals from contaminated soils using EDTA incorporating resin trapping techniques,” Environmental Pollution, vol. 103, no. 1, pp. 135–142, 1998.
[42]
P. Theodoratos, N. Papassiopi, T. Georgoudis, and A. Kontopoulos, “Selective removal of lead from calcareous polluted soils using the Ca-EDTA salt,” Water, Air, and Soil Pollution, vol. 122, no. 3-4, pp. 351–368, 2000.
[43]
A. Bermond and J. P. Ghestem, “Kinetic study of trace metal EDTA-desorption from contaminated soils,” in Heavy Metals Release in Soils, H. M. Selim and D. L. Sparks, Eds., pp. 131–147, Lewis, 2001.
[44]
A. Bermond, “Limits of sequential extraction procedures re-examined with emphasis on the role of H+ ion reactivity,” Analytica Chimica Acta, vol. 445, no. 1, pp. 79–88, 2001.
[45]
A. Polettini, R. Pomi, E. Rolle et al., “A kinetic study of chelant-assisted remediation of contaminated dredged sediment,” Journal of Hazardous Materials, vol. 137, no. 3, pp. 1458–1465, 2006.
[46]
D. F. Kalf, M. A. G. T. Hoop van den, J. P. Rila, C. Posthuma, and T. P. Traas, “Environmental Risk Limits for Ethylene Diamine Tetra Acetic acid (EDTA). Rijksinstituut voor Volksgezondheid en Milieu RIVM (Ed.),” RIVM Report 601501010/2003, Bilthoven, The Netherlands, 2003.
[47]
D. Jiraroj, F. Unob, and A. Hagège, “Degradation of Pb-EDTA complex by a H2O2/UV process,” Water Research, vol. 40, no. 1, pp. 107–112, 2006.
[48]
M. Pociecha and D. Lestan, “EDTA leaching of Cu contaminated soil using electrochemical treatment of the washing solution,” Journal of Hazardous Materials, vol. 165, no. 1–3, pp. 533–539, 2009.
[49]
A. Tessier, P. G. C. Campbell, and M. Blsson, “Sequential extraction procedure for the speciation of particulate trace metals,” Analytical Chemistry, vol. 51, no. 7, pp. 844–851, 1979.
[50]
A. M. Ure, “Single extraction schemes for soil analysis and related applications,” Science of the Total Environment, vol. 178, pp. 3–10, 1996.
[51]
H. A. van der Sloot, R. N. J. Comans, and O. Hjelmar, “Similarities in the leaching behaviour of trace contaminants from waste, stabilized waste, construction materials and soils,” Science of the Total Environment, vol. 178, pp. 111–126, 1996.
[52]
D. W. Nelson and L. E. Sommers, “Total carbon, organic carbon and organic matter,” in Methods of Soil Analysis, part 2: Chemical and Biological Properties, pp. 516–593, 2nd edition, 198.
[53]
R. Chhabra, J. Pleysier, and A. Cremers, “The measurement of the cation exchange capacity and exchangeable cations in soils: a new method,” in Proceedings of the International Clay Conference, S. W. Bailey, Ed., pp. 439–449, Applied Publishing Ltd, Wilmette, Ill, USA, 1975.
[54]
L. P. van Reeuwijk, Procedures for Soil Analysis, ISRIC, Wageningen, The Netherlands, 3rd edition, 1992.
[55]
C. A. Brockhoff, J. T. Creed, T. D. Martin, E. R. Martin, and S. E. Long, “EPA Method 200.8, Revision 5.5: determination of trace metals in waters and wastes by inductively coupled plasma-mass spectrometry,” EPA-821R-99-017, p. 61 , October 1999.
[56]
R. Webster, “Regression and functional relations,” European Journal of Soil Science, vol. 48, no. 3, pp. 557–566, 1997.
[57]
R. Webster, “Statistics to support soil research and their presentation,” European Journal of Soil Science, vol. 52, no. 2, pp. 331–340, 2001.
[58]
P. Quevauviller, E. A. Maier, B. Griepink, U. Fortunati, K. Vercoutere, and H. Muntau, “Certified reference materials of soils and sewage sludges for the quality control of trade element environmental monitoring,” Trends in Analytical Chemistry, vol. 15, no. 10, pp. 504–513, 1996.
[59]
M. Pueyo, G. Rauret, D. Lück et al., “Certification of the extractable contents of Cd, Cr, Cu, Ni, Pb and Zn in a freshwater sediment following a collaboratively tested and optimised three-step sequential extraction procedure,” Journal of Environmental Monitoring, vol. 3, no. 2, pp. 243–250, 2001.
[60]
P. Quevauviller, G. Rauret, A. Ure, J. Bacon, and H. Muntau, “The certification of the EDTA and acetic acid-extractable contents (mass fractions) of Cd, Cr, Cu, Pb and Zn in sewage sludge amended soils CRMs 484 and 484,” European Commision, BCR information, Reference materials. EUR 17127 EN, p. 99, 1997.
[61]
A. E. Martell and R. M. Smith, Critical Stability Constants. Other Organic Ligands, vol. 3, Plenum Press, New York, NY, USA, 1977.
[62]
A. E. Martell and R. M. Smith, Critical Stability Constants. First Supplement, vol. 5, Plenum Press, New York, NY, USA, 1982.
[63]
W. A. Norvell, “Reactions of metal chelates in soil and nutrient solutions,” in Microelements in Agriculture, J. J. Mortvedt, F. R. Cox, L. M. Shuman, and R. M. Welch, Eds., pp. 187–227, Soil Science Society of America, Madison, Wis, USA, 2nd edition, 1991.
[64]
T. E. Furia, “Chapter 6—sequestrants in foods,” in CRC Handbook of Food Additives, pp. 271–294, CRC Press, West Palm Beach, Fla, USA, 2nd edition, 1972.
[65]
J. W. Buthing and K. M. Thong, “Stability constants for some 1 : 1 metal-carboxylate complexes,” Canadian Journal of Chemistry, vol. 48, pp. 1654–1656, 1970.
[66]
C. Kim, Y. Lee, and S. K. Ong, “Factors affecting EDTA extraction of lead from lead-contaminated soils,” Chemosphere, vol. 51, no. 9, pp. 845–853, 2003.
[67]
W. W. Wenzel, N. Kirchbaumer, T. Prohaska, G. Stingeder, E. Lombi, and D. C. Adriano, “Arsenic fractionation in soils using an improved sequential extraction procedure,” Analytica Chimica Acta, vol. 436, no. 2, pp. 309–323, 2001.
[68]
S. Tokunaga and T. Hakuta, “Acid washing and stabilization of an artificial arsenic-contaminated soil,” Chemosphere, vol. 46, no. 1, pp. 31–38, 2002.
[69]
V. Cappuyns, Heavy metal behaviour in overbank sediments and associated soils, Ph.D. thesis, Katholieke Universiteit Leuven, 2004.
[70]
S. M. Rodrigues, B. Henriques, E. F. da Silva et al., “Evaluation of an approach for the characterization of reactive and available pools of 20 potentially toxic elements in soils: part II—Solid-solution partition relationships and ion activity in soil solutions,” Chemosphere, vol. 81, no. 11, pp. 1560–1570, 2010.
[71]
S. P. Singh, F. M. G. Tack, and M. G. Verloo, “Solid-phase distribution of heavy metals as affected by single reagent extraction in dredged sediment derived surface soils,” Chemical Speciation and Bioavailability, vol. 8, no. 1-2, pp. 37–43, 1996.
[72]
G. Du Laing, N. Bogaert, F. M. G. Tack, M. G. Verloo, and F. Hendrickx, “Heavy metal contents (Cd, Cu, Zn) in spiders (Pirata piraticus) living in intertidal sediments of the river Scheldt estuary (Belgium) as affected by substrate characteristics,” Science of the Total Environment, vol. 289, no. 1–3, pp. 71–81, 2002.
[73]
D. McGrath, “Application of single and sequential extraction procedures to polluted and unpolluted soils,” Science of the Total Environment, vol. 178, pp. 37–44, 1996.
[74]
T. Filipek and L. Pawlowski, “Total and extractable heavy metal content of some soils of the Lublin coal mining region,” Science of the Total Environment, vol. 96, no. 1-2, pp. 131–137, 1990.
[75]
S. Sauvé, W. Hendershot, and H. E. Allen, “Solid-solution partitioning of metals in contaminated soils: dependence on pH, total metal burden, and organic matter,” Environmental Science and Technology, vol. 34, no. 7, pp. 1125–1131, 2000.
[76]
P. F. R？mkens, H. Y. Guo, C. L. Chu, T. S. Liu, C. F. Chiang, and G. F. Koopmans, “Characterization of soil heavy metal pools in paddy fields in Taiwan: chemical extraction and solid-solution partitioning,” Journal of Soils and Sediments, vol. 9, no. 3, pp. 216–228, 2009.
[77]
T. J. Schr？der, T. Hiemstra, J. P. M. Vink, and S. E. A. T. M. Van Der Zee, “Modeling of the solid-solution partitioning of heavy metals and arsenic in embanked flood plain soils of the rivers rhine and meuse,” Environmental Science and Technology, vol. 39, no. 18, pp. 7176–7184, 2005.
[78]
V. Cappuyns, R. Swennen, and J. Verhulst, “Assessment of heavy metal mobility in dredged sediments: porewater analysis, single and sequential extractions,” Soil and Sediment Contamination, vol. 15, no. 2, pp. 169–186, 2006.
[79]
S. M. Rodrigues, B. Henriques, E. F. da Silva, M. E. Pereira, A. C. Duarte, and P. F. A. M. R？mkens, “Evaluation of an approach for the characterization of reactive and available pools of twenty potentially toxic elements in soils: part I—The role of key soil properties in the variation of contaminants' reactivity,” Chemosphere, vol. 81, no. 11, pp. 1549–1559, 2010.
[80]
J. E. Groenenberg, Evaluation of models for metal partitioning and speciation in soils and their use in risk assessment Thesis, Ph.D. thesis, Wageningen University, 2011.
[81]
D. Bakircioglu, Y. Bakircioglu-Kurtulus, and H. Ibar, “Comparison of extraction procedures for assessing soil metal bioavailability of to wheat grains,” Clean, vol. 39, no. 8, pp. 728–734, 2011.
[82]
E. C. Anyanwu, K. Ijeoma, J. E. Ehiri, and M. A. Saleh, “Bioavailable” Lead Concentration in Vegetable Plants grown in Soil from a reclaimed industrial site: health implications,” Internet Journal of Food Safety, vol. 6, pp. 31–34, 2005.
[83]
A. K. Gupta and S. Sinha, “Assessment of single extraction methods for the prediction of bioavailability of metals to Brassica juncea L. Czern. (var. Vaibhav) grown on tannery waste contaminated soil,” Journal of Hazardous Materials, vol. 149, no. 1, pp. 144–150, 2007.
[84]
J. M. Soriano-Disla, I. Gómez, J. Navarro-Pedre？o, and A. Lag-Brotons, “Evaluation of single chemical extractants for the prediction of heavy metal uptake by barley in soils amended with polluted sewage sludge,” Plant and Soil, vol. 327, no. 1, pp. 303–314, 2010.
[85]
W. J. G. M. Peijnenburg, M. Zablotskaja, and M. G. Vijver, “Monitoring metals in terrestrial environments within a bioavailability framework and a focus on soil extraction,” Ecotoxicology and Environmental Safety, vol. 67, no. 2, pp. 163–179, 2007.
[86]
J. Pettersen and E. G. Hertwich, “Critical review: life-cycle inventory procedures for long-term release of metals,” Environmental Science and Technology, vol. 42, no. 13, pp. 4639–4647, 2008.
