Catalytic Kinetic Determination of Silver through its Catalytic Effect on Congo Red-Peroxodisulphate Reaction

Document Type : Research Article

Authors

1 Department of Chemistry, Malek-e-Ashtar University of Technology, Shahinshahr, I. R. Iran

2 Department of Chemistry, Lorestan University, Khorramabad, I. R. Iran

10.30492/ijcce.2003.8184

Abstract

A kinetic-spectrophotometric procedure is reported for determination of trace amounts of Ag(I). This method is based on catalytic effect of silver ion on the oxidation of congo red by potassium peroxodisulphate at pH=3.4 and 30 oC in the presence of 1,10-phenanthroline as an activator. The reaction was followed spectrophotometrically by measuring the rate of change in absorbance of congo red at 510 nm in the range of 30-330 seconds after initiation of the reaction. Silver can be determined in the range 2-100 and 100-1100 ng/ml with detection limit 1 ng/ml. Ten replicate analysis of a sample solution containing 8 ng/ml silver gave a relative standard deviation of 1.0%. This method was used for determination of silver in water and photographic plate samples.

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[1] Kiker, R. E. and Othmer, D. F, "Encyclopedia of Chemical Technology", John Wiely and Sons (1980).
[2] U. Eisner, U. and Mark, H. B., J. Electro Anal. Chem, 24, 345 (1970).
[3] Wang, J. and Martinz, T., Anal. Chim. Acta, 207, 95(1988).
[4] Howlett, C. and Taylor, A., Analyst, 103, 916(1978).
[5] Cordoba, H. and Pedreno, S, Quim, Anal., 9(2), 159(1985).
[6] Agrawal, G. L. and Chourasia, R., Asian J. of Chemistry, 12, Iss 3, 857(2000).
[7] Safavi, A. and Haghighi, B., Fresenius J. Anal. Chem., 357, 870(1997).
[8] Zhu, H.,  Peng, A. and Yang, X., Fenxi Huaxue, 20, 742(1992).
[9] Egorova, M. B. and Drobachenko, A. V., Probl. Sovren. Anal. Khim., 4, 172(1983).
[10] Zhang, Z. and Ling, L., Gaodeng Xueniao Huaxue Xuebao, 12, 462(1991).
[11] Ensafi, A. A. and  Abbasi, A., Anal. Lett., 30(2), 327(1997).
[12] Ensafi, A. A. and Zarei, K., Fresenius J. Anal. Chem., 358, 475(1997).
[13] Ingels, J. D. and Crouch, S. R.,  "Spectrochemical Analysis", Prentic-Hall  (1988).