1. Department of Chemical Sciences, Tezpur University, Tezpur, Assam 784028, India
2. Department of Chemistry, Electrochemistry and Chemistry of Materials, Faculty of Science, University of Dschang, P. O. Box 67, Dschang, Cameroon
3. Department of Chemistry, Higher Teacher Training College, University of Bamenda, Bambili P. O. Box. 39, Cameroon
4. Department of Chemistry, Laboratory of Analytical Chemistry, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon