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 AJAC  Vol.2 No.1 , February 2011
Elucidation of Abnormal Potential Responses of Cation-Selective Electrodes with Solid-State Membranes to Aqueous Solutions of CuCl2 and CdI2
Abstract: An empirical solution to abnormal potential responses, showing peaks of emf, of commercial Cu2+- and Cd2+-selective electrodes with solid-state membranes was proposed for aqueous solutions of CuCl2 and CdI2. The two-step processes of Mn+ + Yn? (s: solid phase) MY(s) and MY(s) + 2X? X2MY2?(s) (n = 1, 2) at a test solution/electrode-interface were considered as a model. Here, Mn+, Yn?, and X? refer to a divalent or univalent cation, functional groups of electrode materials, and a halide ion (X? = Cl?, Br?, I?), respectively. By applying electrochemical potentials to these processes at n = 2, we derived an equation. Regression analyses based on the equation reproduced well the plots of emf versus log 2(*[M]t) for the Cd(II) and Cu(II) systems: *[M]t denotes a total concentration of species relevant to M2+ in a bulk of the aqueous solution. Also, we obtained log Ks(CdBr2) = 4.28 ? 0.22, log Ks(CdI2) = 6.98 ? 0.05, log Ks(CuCl2) = 3.96 ? 0.09, and log Ks(CuBr2) = 11.4 at 25?C. The magnitude in ?log Ks reflected that in the logarithmic solubility product, log {*[M2+](*[X?])2}, for bulk water, where *[M2+] or *[X?] denotes a molar concentration of the bulk solu-tion of M2+ or X? at equilibrium, respectively. Moreover, a mixture of CuSO4 with NaCl at the molar ratio of 1:1 yielded a plot similar to that of CuCl2.
Cite this paper: nullY. Kudo, D. Todoroki, N. Suzuki, N. Horiuchi, S. Katsuta and Y. Takeda, "Elucidation of Abnormal Potential Responses of Cation-Selective Electrodes with Solid-State Membranes to Aqueous Solutions of CuCl2 and CdI2," American Journal of Analytical Chemistry, Vol. 2 No. 1, 2011, pp. 9-17. doi: 10.4236/ajac.2011.21002.
References

[1]   D. N. Hume, D. D. DeFord and G. C. B. Cave, “A Polarographic Study of the Cadmium Thiocyanate Complexes,” Journal of American Chemical Society, Vol. 73, 1951, pp. 5323-5325. doi:10.1021/ja01155a094

[2]   C. E. Vanderzee and H. J. Dawson Jr., “The Stability Constants of Cadmium Chloride Complexes: Variation with Temperature and Ionic Strength,” Journal of American Chemical Society, Vol. 75, 1953, pp. 5659- 5663. doi:10.1021/ja01118a056

[3]   P. Gerding, “Thermochemical Studies on Metal Complexes I. Free Energy, Enthalpy, and Entropy Changes for Stepwise Formation of Cadmium(II) Halide Complexes in Aqueous Solution at 25?C,” Acta Chimca Scandinavica, Vol. 20, No. 1, 1966, pp. 79-94. doi:10.3891/acta.chem.scand.20-0079

[4]   Y. Kudo, D. Todoroki, N. Horiuchi, S. Katsuta and Y. Takeda, “Ion-Pair Formation of Sodium Salts of Several Oxo Anions and Cadmium Halides in Water and the Distribution of Monovalent Sulfate Ion Pairs in Nitrobenzene,” Journal of Chemical and Engineering Data, Vol. 55, No. 7, 2010, pp. 2463-2469. doi:10.1021/je900861h

[5]   W. E. Morf and W. Simon, “Cation-Response Mechanism of Neutral Carrier Based Ion-Selective Electrode Membranes,” Helvetica Chimica Acta, Vol. 69, 1986, pp. 1120-1131. doi:10.1002/hlca.19860690520

[6]   E. Lindner, E. Gráf, Z. Niegreisz, K. Tóth, E. Pungor and R. P. Buck, “Responses of Site-Controlled, Plasticized Membrane Electrodes,” Analytical Chemistry, Vol. 60, No. 4, 1988, pp. 295-301. doi:10.1021/ac00155a004

[7]   V. V. Egorov and Y. F. Lushchik, “H+-Selective Electrodes Based on Neutral Carriers: Specific Features in Behaviour and Quantitative Description of the Electrode Response,” Talanta, Vol. 37, No. 5, 1990, pp. 461-469. doi:10.1016/0039-9140(90)80071-M

[8]   Y. Kudo, Y. Kobayashi, S. Katsuta and Y. Takeda, “Ion- pair Formation of Cadmium-18-Crown-6 Ethers Complex Ions with Picrate and Chloride Ions in Water and Distribution of Its Picrate Ion-pair Complexes into Benzene,” Journal of Molecular Liquids, Vol. 146, 2009, pp. 60-65. doi:10.1016/j.molliq.2009.02.004

[9]   T. Kakiuchi and M. Senda, “The Theory of Liquid Ion Exchange Membrane Ion-Selective Electrodes Based on the Concept of the Mixed Ion-Transfer Potential,” Bulletin of the Chemical Society of Japan, Vol. 57, No. 7, 1984, pp. 1801-1808. doi:10.1246/bcsj.57.1801

[10]   A. Jyo, K. Fukamachi, W. Koga and N. Ishibashi, “The Influence of a Co-ion on the Potential of a Liquid -Exchanger Membrane Electrode,” Bulletin of the Chemical Society of Japan, Vol. 50, No. 3, 1977, pp. 670-672. doi:10.1246/bcsj.50.670

[11]   P. Bühlmann and Y. Umezawa, “Apparently ‘Non-Nern- stian’ Equilibrium Responses Based on Complexation Between the Primary Ion and a Secondary Ion in the Liquid ISE Membrane,” Electroanalysis, Vol. 11, No. 10-11, 1999, pp. 687-693. doi:10.1002/(SICI)1521-4109(199907) 11:10/11<687::AID-ELAN687>3.0.CO;2-C

[12]   S. Amemiya, P. Bühlmann and K. Odashima, “A Generalized Model for Apparently “Non-Nernstian” Equilibrium Responses of Ionophore-Based Ion-Selective Electrodes. 1. Independent Complexation of the Ionophore with Primary and Secondary Ions,” Analytical Chemistry, Vol. 75, No. 14, 2003, pp. 3329-3339. doi:10.1021/ac026471g

[13]   G. D. Christian, “Analytical Chemistry,” 5th Edition, John Wiley & Sons, New York, 1994, p. 335.

[14]   Y. Kudo, R. Fujihara, T. Ohtake, S. Katsuta and Y. Takeda, “Evaluation of the Hydrophilic Property of Sodium Ion-Pair Complexes with 3m-Crown-m Ethers (m = 5, 6) and Their Benzo-Derivatives by Solvent Extraction,” Analytical Sciences, Vol. 24, 2008, pp. 999-1003. doi:10.2116/analsci.24.999

[15]   Y. Kudo, S. Takeuchi, Y. Kobayashi, S. Katsuta and Y. Takeda, “Potentiometric Determination of Ion-Pair Formation Constants for Cadmium, Calcium Salts, and Cadmium-18-Crown-6 Ether Derivative Complexes with a Sulfate Ion in Water,” Journal of Chemical and Engineering Data, Vol. 52, No. 5, 2007, pp. 1747-1752. doi:10.1021/je700135j

[16]   S. Wasylkiewicz, “Ion Association in Aqueous Solutions of Electrolytes. II. Mathematical Model for Sulphates of Bivalent Metals,” Fluid Phase Equilibria, Vol. 57, 1990, pp. 277-296. doi:10.1016/0378-3812(90)85127-V

[17]   T. Kakiuchi, “Limiting Behanior in Equilibrium Partitioning of Ionic Components in Liquid-Liquid Two-Phase Systems,” Analytical Chemistry, Vol. 68, No. 20, 1996, pp. 3658-3664. doi:10.1021/ac960032y

[18]   Internet Available: http://www.horiba.com/us/en/applica- tion/material-property-characterization/water-analysis/wa- ter-quality-electrochemistry-instrumentation/electrodes/ion-electrodes/details/copper-ion-electrode-8006-10c-9511/

[19]   Internet Available: http://www.horiba.com/us/en/applica- tion/material-property-characterization/water-analysis/wa- ter-quality-electrochemistry-instrumentation/electrodes/ion-electrodes/details/cadmium-ion-electrode-8007-10c-9515/

[20]   Internet Available: http://www.horiba.com/us/en/applica- tion/material-property-characterization/water-analysis/wa- ter-quality-electrochemistry-instrumentation/electrodes/ion-electrodes/details/calcium-ion-electrode-8203-10c-9587/

[21]   A. J. Bird and L. R. Faulkner, “Electrochemical Methods: Fundamentals and Applications,” 2nd Edition, John Wiley & Sons, New York, 2001, pp. 60-62; 74-81.

[22]   K. A. Inaba, S. Takagi, K. Tajima, H. Tohara, K. Nakatsuka, K. Nakanishi, H. Nakayama, T. Makita and M. Muramatsu, “Handbook of Chemistry, Fundamentals II”, In: H. Chihara, Ed., 3rd Edition, The Chemical Society of Japan, Maruzen, Tokyo, 1984, pp. II-166; II-177.

 
 
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