Studies in the polarography of metal-amino acid complexes

Part II. Lead
  • G. Nageswara Rao
  • R. S. Subrahmanya
Article

Summary

1. The polarographic behaviour of glycine,α-alanine,β-alanine, valine, aspartic acid, glutamic acid and asparagine complexes of lead has been studied at various pH values and in presence of (1) NaOH, (2) Na2CO3 and (3) NH4 NO3+NH4OH. All the polarographic waves have been found to be reversible.

2. Experiments conducted on the effect of variation of pH,i.e., 7<pH<9 (varying slightly in different cases), on half-wave potential keeping the total concentration of amino-acid have indicated the formation of Pb A and Pb A2. The data have been analysed employing the equations developed by DeFord and Hume as modified by McKenzie and Mellor.

3. Only pure complexes are produced below pH 11·2 in the case of aspartic acid, glutamic acid and glycine, while mono hydroxy complexes are produced inα-alanine, valine and asparagine systems.

4. It has been found that no mixed hydroxy and mixed ammonia complexes are produced in presence of sodium hydroxide and ammonia-ammonium nitrate, respectively. However evidence is obtained for the formation of mixed carbonate complexes in glycine and aspartic acid systems in presence of sodium carbonate.

5. Thermodynamic data have been calculated from polarographic measurements for 18 complexes.

6. The suitability of incorporating amino acids in base solutions for the polarographic estimation of lead has been tested.

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References

  1. 1.
    McKenzie, H. A. and Mellor, D. P.Aust. J. Chem., 1961,14, 562.Google Scholar
  2. 2.
    Bapna, T. and Karmalkar, H.J. Vikram Univ., 1957,3, 101.Google Scholar
  3. 3.
    Nageswara Rao, G. and Subrahmanya, R. S.J. Sci. industr. res., 1962,21 B, 193.Google Scholar
  4. 4.
    —————..Proc. Ind. Acad. Sci., 1964,60 A, 165.Google Scholar
  5. 5.
    Laitinen, H. A., Onstott, E., Bailar, J. C. (Jr.) and Swann, S.J. Amer. Chem. Soc., 1950,72, 2484.CrossRefGoogle Scholar
  6. 6.
    Subrahmanya, R. S...Proc. Ind. Acad. Sci., 1956,43 A, 383.Google Scholar
  7. 7.
    —————.. Ibid., 1957,46 A, 433.Google Scholar
  8. 8.
    Tsai-Teh and Teh Liang ChangAnal. Chem., 1961,33, 1953.CrossRefGoogle Scholar
  9. 9.
    Keefer, R. M. and Reiber, H. G.J. Amer. Chem. Soc., 1941,63, 689.CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 1964

Authors and Affiliations

  • G. Nageswara Rao
    • 1
  • R. S. Subrahmanya
    • 1
  1. 1.Department of Inorganic and Physical ChemistryIndian Institute of ScienceBangalore-12South India

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