Determination of Apparent Formation Constants of Eu(III) with Humic Substances by Ion Selective Liquid Membrane Electrode

Takayuki Sasaki, Hatsumi Yoshida, Taishi Kobayashi, Ikuji Takagi, Hirotake Moriyama

Department of Nuclear Engineering, Kyoto University, Kyoto, Japan.
Research Reactor Institute, Kyoto University, Osaka, Japan.

DOI: 10.4236/ajac.2012.37061                

Abstract

This is the novel measurement of the apparent formation constants of trivalent lanthanide with humic substances by potentiometric titration using an ion selective electrode (ISE) consisting of bis(diphenylphosphoryl)methane as an ionophore. The ISE prepared exhibited a Nernstian response to the Eu3+ concentration in the test solutions in the presence of humic acid and fulvic acid. The effect of the solution conditions, including the pH, initial metal and humic substance concentrations, and ionic strength, on the formation constants was examined. The present formation constants were compared with the reported data using solvent extraction method.

Keywords

Apparent Formation Constant; Humic Substance; Eu(III); Ion Selective Electrode; Titration

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	J. I. Kim and T. Sekine, “Complexation of Neptunium(V) with Humic-Acid,” Radiochimica Acta, Vol. 55, No. 4, 1991, pp. 187-192.
[2]	V. Moulin, J. Tits and G. Ouzounian, “Actinide Speciation in the Presence of Humic Substances in Natural-Water Conditions,” Radiochimica Acta, Vol. 58, 1992, pp. 179-190.
[3]	Y. Takahashi, Y. Minai, S. Ambe, Y. Makide, F. Ambe and T. Tominaga, “Simultaneous Determination of Sta-bility Constants of Humate Complexes with Various Metal Ions Using Multitracer Technique,” Science of the Total Environment, Vol. 198, No. 1, 1997, pp. 61-71. doi:10.1016/S0048-9697(97)05442-9
[4]	D. Wenming, Z. Hongxia, H. Meide and T. Zuyi, “Use of the Ion Exchange Method for the Determination of Stability Constants of Trivalent Metal Complexes with Humic and Fulvic Acids—Part I: Eu3+ and Am3+ Complexes in Weakly Acidic Conditions,” Applied Radiation and Isotopes, Vol. 56, No. 6, 2002, pp. 959-965. doi:10.1016/S0969-8043(01)00055-0
[5]	M. Schnitzer and S. I. M. Skinner, “Organo-Metallic Interactions in Soils: 7. Stability Constants of Pb++-, Ni++-, Mn++-, Co++-, Ca++-, and Mg++-Fulvic Acid Complexes,” Soil Science, Vol. 103, No. 4, 1967, pp. 247-252. doi:10.1097/00010694-196704000-00004
[6]	M. Schnitzer and S. I. M. Skinner, “Organo-Metallic Interactions in Soils: 5. Stability Constants of Cu++-, Fe++-, and Zn++-Fulvic Acid Complexes,” Soil Science, Vol. 102, No. 6, 1966, pp. 361-365. doi:10.1097/00010694-196612000-00002
[7]	M. Caceci, “The Interaction of Humic-Acid with Europium(III) Complexation Strength as a Function of Load and pH,” Radiochimica Acta, Vol. 39, 1985, pp. 51-56.
[8]	J. H. Ephraim, “Heterogeneity as a Concept in the Interpretation of MetalIon Binding by Humic Substances - The Binding of Zinc by an Aquatic Fulvic Acid,” Analytica Chimica Acta, Vol. 267, No. 1, 1992, pp. 39-45. doi:10.1016/0003-2670(92)85004-P
[9]	M. A. Glaus, W. Hummel and L. R. Van Loon, “Equilibrium Dialysis-Ligand Exchange: Adaptation of the Method for Determination of Conditional Stability Constants of Radionuclide-Fulvic Acid Complexes,” Analytica Chimica Acta, Vol. 303, No. 2-3, 1995, pp. 321- 331. doi:10.1016/0003-2670(94)00534-S
[10]	A. Kirishima, T. Ohnishi, N. Sato and O. Tochiyama, “Simplified Modeling of the Complexation of Humic Substance for Equilibrium Calculations,” Journal of Nuclear Science and Technology, Vol. 47, No. 11, 2010, pp. 1044-1054. doi:10.1080/18811248.2010.9711669
[11]	J. G. Hering and F. M. M. Morel, “Humic Acid Complexation Calcium and Copper,” Environmental Science and Technology, Vol. 22, No. 10, 1988, pp. 1234-1237. doi:10.1021/es00175a018
[12]	J. P. Pinheiro, A. M. Mota and M. F. Benedetti, “Lead and Calcium Binding to Fulvic Acids: Salt Effect and Competition,” Environmental Science and Technology, Vol. 33, No. 19, 1999, pp. 3398-3404. doi:10.1021/es990210f
[13]	T. Ito, C. Goto and K. Noguchi, “Lanthanoid Ion-Selective Solvent Polymeric Membrane Electrode Based on 1-Phenyl-3-Methyl-4-Octadecanoyl-5-Pyrazolone,” Analytica Chimica Acta, Vol. 443, No. 1, 2001, pp. 41-51. doi:10.1016/S0003-2670(01)01192-8
[14]	M. R. Ganjali, N. Davarkhah, H. Ganjali, B. Larijani, P. Norouzi and M. Hossieni, “A Novel Europium(III) Sensor Based on 4E-4-(2-phenylviazenyl)-2-((E)-(2-aminoethyli - mino)methyl)phenol,” International Journal of Electrochemical Science, Vol. 4, No. 6, 2009, pp. 762-771.
[15]	J. B. Harrell, A. D. Jones and G. R. Choppin, “A Liquid Ion-Exchange Mem-brane Electrode for Polyvalent Cations,” Analytical Chemistry, Vol. 41, No. 11, 1969, pp. 1459-1462. doi:10.1021/ac60280a026
[16]	D. A. Chowdhury, T. Ogata, S. Kamata and K. Ohashi, “Samarium(III)-Selective Electrode Using Neutral Bis (thiaalkylxanthato)alkanes,” Analytical Chemistry, Vol. 68, No. 2, 1996, pp. 366-370. doi:10.1021/ac950814b
[17]	Y. Kitatsuji, H. Aoyagi, Z. Yoshida and S. Kihara, “Plutonium(III)-Ion Selective Electrode of Liquid Membrane Type Using Multidentate Phosphine Oxide Ionophore,” Analytica Chimica Acta, Vol. 387, No. 2, 1999, pp. 181- 187. doi:10.1016/S0003-2670(99)00121-X
[18]	T. Sasaki, H. Yoshida, Y. Kitatsuji, I. Takagi and H. Moriyama, “Formation Constants of Eu(III)-Carboxylates Determined by Ion Selective Liquid Membrane Electrode,” Chemistry Letters, Vol. 40, 2011, pp. 870-871. doi:10.1246/cl.2011.870
[19]	J. I. Kim, G. Buckau, G. H. Li, H. Duschner and N. Psarros, “Characterization of Humic and Fulvic Acids from Gorleben Groundwater,” Fresenius Journal of Analytical Chemistry, Vol. 338, No. 3, 1990, pp. 245-252. doi:10.1007/BF00323017
[20]	A. Kirishima, T. Ohnishi, N. Sato and O. Tochiyama, “Determination of the Phenolic-Group Capacities of Humic Substances by Non-Aqueous Titration Technique,” Talanta, Vol. 79, No. 2, 2009, pp. 446-453. doi:10.1016/j.talanta.2009.04.008
[21]	T. Sasaki, S. Aoyama, H. Yoshida, Y. Kulyako, M. Samsonov, T. Kobayashi, I. Takagi, B. Miyasoedov and H. Moriyama, “Apparent Formation Constants of Pu(IV) and Th(IV) with Humic Acids Determined by Solvent Extraction Method,” Radiochimica Acta, 2012, in press.
[22]	“International Humic Substances Society,” 2012. http://www.humicsubstances.org
[23]	G. Gran, “Determination of the Equivalence Point in Potentiometric Titrations. Part II,” Analyst, Vol. 77, No. 920, 1952, pp. 661-671. doi:10.1039/an9527700661
[24]	K. Fujiwara, H. Yamana, T. Fujii, K. Kawamoto, T. Sasaki and H. Moriyama, “Solubility of Uranium(IV) Hydrous Oxide in High pH Solution Under Reducing Condition,” Radiochimica Acta, Vol. 93, No. 6, 2005, pp. 347- 350. doi:10.1524/ract.93.6.347.65643
[25]	T. Sasaki, S. Kubo, T. Kubota, I. Takagi and H. Moriyama, “Complex Formation of Lanthanides(III) and Actinides(III) with Dicarboxylates Containing Soft Donor Groups,” Journal of Alloys and Compounds, Vol. 408- 412, 2006, pp. 1283-1286. doi:10.1016/j.jallcom.2005.04.130
[26]	C. F. Baes and R. E. Mesmer, “The Hydrolysis of Cations,” John Wiley & Sons, New York, 1976.
[27]	J. Du, N. Sato and O. Tochiyama, “Potentiometric Study on the Proton Binding of Humic Substances,” Journal of Nuclear and Radiochemical Sciences, Vol. 6, No. 1, 2005, pp. 25-29.
[28]	O. Tochiyama, Y. Nibbori, K. Tanaka, H. Yoshino, T. Kubota, A. Kirishima and B. Setiawan, “Modeling of the Complex Formation of Metal Ions with Humic Acids,” Radiochimica Acta, Vol. 92, No. 9-11, 2004, pp. 559-565. doi:10.1524/ract.92.9.559.54996
[29]	K. Müller and T. Sasaki, “Complex Formation of Np(V) with Fulvic Acid at Tracer Metal Concentration,” Radiochimica Acta, 2012, in press.
[30]	T. Sasaki, T. Kobayashi, I. Takagi and H. Moriyama, “Discrete Fragment Model for Complex Formation of Europium(III) with Humic Acid,” Journal of Nuclear Science and Technology, Vol. 45, No. 8, 2008, pp. 718- 724. doi:10.3327/jnst.45.718
[31]	W. Hummel, M. A. Glaus and L. R. Van Loon, “Trace Metal-Humate Interactions. II. The ‘Conservative Roof” Model and Its Application,” Applied Geochemistry, Vol. 15, 2000, pp. 975-1001. doi:10.1016/S0883-2927(99)00100-6