1. Applied Chemistry Department; S.V. National Institute of Technology; Surat - 395 007, Gujarat India
2. Salt and Marine Chemicals Division; CSIR-Central Salt and Marine Chemicals Research Institute; G. B. Marg Bhavnagar - 364002 India
3. Institute of Chemistry; The University of São Paulo, P. O. Box 26077; 05513-970 São Paulo, SP Brazil