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Environmental problems - Chemical approaches
RESEARCH ARTICLE

Palladium(II) sequestration by phytate in aqueous solution – speciation analysis and ionic medium effectsA

Antonio Gianguzza A , Demetrio Milea B , Alberto Pettignano A and Silvio Sammartano B C
+ Author Affiliations
- Author Affiliations

A Dipartimento di Chimica Inorganica e Analitica ‘Stanislao Cannizzaro’, Università di Palermo, Viale delle Scienze, I-90128 Palermo, Italy.

B Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, Salita Sperone, 31, I-98166 Messina (Vill. S. Agata), Italy.

C Corresponding author. Email: ssammartano@unime.it

Environmental Chemistry 7(3) 259-267 https://doi.org/10.1071/EN10008
Submitted: 25 January 2010  Accepted: 24 March 2010   Published: 22 June 2010

Environmental context. In the last 20 years, the demand for palladium and other platinum-group elements has intensified, causing a significant increase in their concentration in the environment, with particular accumulation in urban areas. Knowledge about Pd2+ speciation in aqueous media is fundamental for the understanding of its biological and environmental activity in contaminated areas. Phytic acid appears to be a good sequestering agent towards Pd2+ under various conditions, indicating its potential use in the remediation of contaminated sites.

Abstract.  Palladium(II) speciation in the presence of phytate (Phy12–) was studied by H+ ion selective electrode (ISE) potentiometry at 25°C in NaNO3(aq) and in NaCl(aq) at ionic strength I = 0.1 mol L–1, in order to evaluate the effect of the ionic medium on the sequestering ability of phytate towards palladium(II). Owing to the discrepancies found in the literature on both the nature and the stability of hydrolytic species formed by this cation, Pd2+ hydrolysis was studied under the same experimental conditions as phytate/PdII measurements. As palladium(II) forms stable complex species with the chloride ion, the stability constants of various Pd2+–Cl species were also calculated, as well as those of weak species formed with nitrate. The stability constants of six palladium(II)–phytate species, namely PdPhyOH11–, PdPhy10–, PdPhyH9–, PdPhyH28–, PdPhyH37– and PdPhyH46–, were determined. The sequestering ability of this ligand towards Pd2+ was evaluated by the calculation of various pL50 values (total ligand concentrations, as antilogarithm, necessary to bind the 50% of the metal ion as a trace present in the solution) under different conditions. Phytate sequestering ability towards palladium(II) was then compared with that towards other divalent cations under various conditions. Finally, the dependence of pL50 on pH was modelled by a simple empirical relationship.

Additional keywords: complexes, stability constants.


Acknowledgements

A. Gianguzza and A. Pettignano thank the University of Palermo for financial support; D. Milea and S. Sammartano thank the University of Messina for financial support.


References


[1]   C. De Stefano , G. Lando , D. Milea , A. Pettignano , S. Sammartano , Formation and stability of cadmium(II)/phytate complexes by different electrochemical techniques. Critical analysis of results. J. Solution Chem. 2010 , 39,  179.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[2]   F. Crea , C. De Stefano , D. Milea , S. Sammartano , Formation and stability of phytate complexes in solution. Coord. Chem. Rev. 2008 , 252,  1108.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[3]   Essington M. E., Soil and Water Chemistry: an Integrative Approach 2004 (CRC Press, Inc.: Boca Raton, FL).

[4]   B. F. Harland , E. R. Morris , Phytate: a good or a bad food component? Nutr. Res. 1995 , 15,  733.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[5]   J. C. Seaman , J. M. Hutchison , B. P. Jackson , V. M. Vulava , In situ treatment of metals in contaminated soils with phytate. J. Environ. Qual. 2003 , 32,  153.
        |  CAS | | Crossref | PubMed |  open url image1

[6]   K. L. Nash , M. P. Jensen , M. A. Schmidt , Actinide immobilization in the subsurface environment by in-situ treatment with a hydrolytically anstable organophosphorus complexant: uranyl uptake by calcium phytate. J. Alloy. Comp. 1998 , 271–273,  257.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[7]   A. S. Knox , R. L. Brigmon , D. I. Kaplan , M. H. Paller , Interactions among phosphate amendments, microbes and uranium mobility in contaminated sediments. Sci. Total Environ. 2008 , 395,  63.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  open url image1

[8]   Renner H., Schmuckler G., Platinum-group metals, in Metals and Their Compounds in the Environment: Occurrence, Analysis, and Biological Relevance (Ed. E. Merian) 1991, pp. 893–908 (VCH: Weinheim, Germany).

[9]   K. H. Ek , G. M. Morrison , S. Rauch , Environmental routes for platinum group elements to biological materials – a review. Sci. Total Environ. 2004 , 334–335,  21.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[10]   Zereini F., Alt F., Palladium Emissions in the Environment 2006 (Springer-Verlag: Berlin).

[11]   C. Colombo , A. J. Monhemius , J. A. Plant , The estimation of the bioavailabilities of platinum, palladium and rhodium in vehicle exhaust catalysts and road dusts using a physiologically based extraction test. Sci. Total Environ. 2008 , 389,  46.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  open url image1

[12]   B. Sures , S. Zimmerman , J. Messerschmidt , A. Von Bohlen , Relevance and analysis of traffic-related platinum group metals (Pt, Pd, Rh) in the aquatic biosphere, with emphasis on palladium. Ecotoxicology 2002 , 11,  385.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  open url image1

[13]   Baes C. F., Mesmer R. E., The Hydrolysis of Cations 1976 (Wiley: New York).

[14]   H. A. Droll , B. P. Block , W. C. Fernelius , Studies on coordination compounds. XV. Formation constants for chloride and acetylacetonate complexes of palladium(II). J. Phys. Chem. 1957 , 61,  1000.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[15]   L. I. Elding , Palladium(II) halide complexes. I. Stabilities and spectra of palladium(II) chloro and bromo aqua complexes. Inorg. Chim. Acta 1972 , 6,  647.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[16]   N. B. Milić , Ž. D. Bugarčić , Hydrolysis of the palladium(II) ion in a sodium chloride medium. Trans. Met. Chem. 1984 , 9,  173.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[17]   C. D. Tait , D. R. Janecky , P. S. Z. Rogers , Speciation of aqueous palladium(II) chloride solutions using optical spectroscopies. Geochim. Cosmochim. Acta 1991 , 55,  1253.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[18]   R. H. Byrne , L. R. Kump , Comment on ‘Speciation of aqueous palladium(II) chloride solutions using optical spectroscopies’ by C. D. Tait, D. R. Janecky, and P. S. Z. Rogers. Geochim. Cosmochim. Acta 1993 , 57,  1151.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[19]   J. M. van Middlesworth , S. A. Wood , The stability of palladium(II) hydroxide and hydroxyl-chloride complexes: an experimental solubility study at 25–85°C and 1 bar. Geochim. Cosmochim. Acta 1999 , 63,  1751.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[20]   R. H. Byrne , W. Yao , Formation of palladium(II) hydroxychloride complexes and precipitates in sodium chloride solutions and seawater. Geochim. Cosmochim. Acta 2000 , 64,  4153.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[21]   J. F. Boily , T. M. Seward , Palladium(II) chloride complexation: spectrophotometric investigation in aqueous solutions from 5 to 125°C and theoretical insight into Pd–Cl and Pd–OH2 interactions. Geochim. Cosmochim. Acta 2005 , 69,  3773.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[22]   J. F. Boily , T. M. Seward , J. M. Charnock , The hydrolysis and precipitation of Pd(II) in 0.6 mol kg–1 NaCl: a potentiometric, spectrophotometric, and EXAFS study. Geochim. Cosmochim. Acta 2007 , 71,  4834.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[23]   K. Burger , D. Dyrssen , On the complex formation of palladium with dimethylglyoxime. Acta Chem. Scand. 1963 , 17,  1489.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[24]   R. M. Izatt , D. Eatough , J. J. Christensen , A study of Pd2+(aq) hydrolysis. Hydrolysis constants and the standard potential for the Pd, Pd2+ couple. J. Chem. Soc. A 1967 , 6,  1301.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[25]   B. I. Nabivanets , L. V. Kalabina , State of palladium(II) in perchlorate solutions. Russ. J. Inorg. Chem. 1970 , 15,  818.
         open url image1

[26]   C. K. Jørgensen , V. Parthasarathy , The influence of nitrate and other anions on the absorption spectra of palladium(II). Acta Chem. Scand. A 1978 , 32a,  957.
        | Crossref | GoogleScholarGoogle Scholar |  open url image1

[27]   E. C. Frias , H. Pitsch , J. Li , C. Poitrenaud , Palladium complexes in concentrated nitrate and acid solutions. Talanta 1995 , 42,  1675.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  open url image1

[28]   T. Shi , L. I. Elding , Equilibria, kinetics and mechanism for complex formation between hydrogen sulphate/sulphate and palladium(II). Hydrolysis of tetraaquapalladium(II). Acta Chem. Scand. 1998 , 52,  897.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[29]   J. M. Cosden , R. H. Byrne , Comparative geochemistries of PdII and PtII: formation of mixed hydroxychloro and chlorocarbonato-complexes in seawater. Geochim. Cosmochim. Acta 2003 , 67,  1331.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[30]   Martell A. E., Smith R. M., Motekaitis R. J., NIST Standard Reference Database 46, Vers. 8 2004 (Gaithersburg, MD).

[31]   J. Purans , B. Fourest , C. Cannes , V. Sladkov , F. David , L. Venault , M. Lecomte , Structural investigation of Pd(II) in concentrated nitric and perchloric acid solutions by XAFS. J. Phys. Chem. 2005 , 109,  11074.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[32]   A. B. Venediktov , S. V. Korenev , S. P. Khranenko , S. V. Tkachev , P. E. Plyusnin , S. N. Mamonov , L. V. Ivanova , V. A. Vostrikov , Properties of nitric acid palladium solutions with a high metal concentration. Russ. J. Appl. Chem. 2007 , 80,  695.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[33]   De Stefano C., Sammartano S., Mineo P., Rigano C., Computer tools for the speciation of natural fluids, in Marine Chemistry – An Environmental Analytical Chemistry Approach (Eds A. Gianguzza, E. Pelizzetti, S. Sammartano) 1997, pp. 71–83 (Kluwer Academic Publishers: Amsterdam).

[34]   Daniele P. G., De Robertis A., De Stefano C., Sammartano S., Ionic strength dependence of formation constants. XIII. A critical examination of preceding results, in Miscellany of Scientific Papers Offered to Enric Casassas (Eds S. Alegret, J. J. Arias, D. Barcelò, J. Casal, G. Router) 1991, pp. 121–126 (Universitata Autonoma: Barcelona, Spain).

[35]   P. Crea , C. De Stefano , D. Milea , N. Porcino , S. Sammartano , Speciation of phytate ion in aqueous solution. Protonation constants and copper(II) interactions in NaNO3aq at different ionic strengths. Biophys. Chem. 2007 , 128,  176.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  open url image1

[36]   C. De Stefano , D. Milea , S. Sammartano , Speciation of phytate ion in aqueous solution. Protonation constants in tetraethylammonium iodide and sodium chloride. J. Chem. Eng. Data 2003 , 48,  114.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[37]   F. Crea , D. Milea , S. Sammartano , Enhancement of hydrolysis through the formation of mixed hetero-metal species. Talanta 2005 , 65,  229.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  open url image1

[38]   F. Crea , C. De Stefano , D. Milea , S. Sammartano , Speciation of phytate ion in aqueous solution. Thermodynamic parameters for zinc(II) sequestration at different ionic strengths and temperatures. J. Solution Chem. 2009 , 38,  115.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[39]   Z. Fan , Z. Jiang , F. Yang , B. Hu , Determination of platinum, palladium and rhodium in biological and environmental samples by low temperature electrothermal vaporization inductively coupled plasma atomic emission spectrometry with diethyldithiocarbamate as chemical modifier. Anal. Chim. Acta 2004 , 510,  45.
        | Crossref | GoogleScholarGoogle Scholar | CAS |  open url image1

[40]   Vogel A. I., Bassett J., Vogel’s Textbook of Quantitative Inorganic Analysis: Including Elementary Instrumental Analysis 1987 (Wiley: New York).

[41]   De Carli L., Rosso N. D., Schnitzler E., Carneir P. I. B., Study of stability of phytic acid with Ni(II) complex. [Estudo da estabilidade do complexo acido fitico e o ion Ni(II)]. Ciencia e Tecnologia de Alimentos 2006, 26, 19. [in Portuguese]

[42]   C. De Stefano , D. Milea , N. Porcino , S. Sammartano , Speciation of phytate ion in aqueous solution. Sequestering ability towards mercury(II) cation in NaClaq at different ionic strengths. J. Agric. Food Chem. 2006 , 54,  1459.
        | Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |  open url image1

[43]   C. De Stefano , D. Milea , N. Porcino , S. Sammartano , Speciation of phytate ion in aqueous solution. Cadmium(II) interactions in NaClaq at different ionic strengths. Anal. Bioanal. Chem. 2006 , 386,  346.
        | Crossref | GoogleScholarGoogle Scholar | PubMed |  open url image1




A This paper is the last contribution of the series on phytate speciation (see C. De Stefano, G. Lando, D. Milea, A. Pettignano, S. Sammartano, Formation and stability of cadmium(II)/phytate complexes by different electrochemical techniques. Critical analysis of results. J. Solution Chem. 2010, 39(2), 179).