1. Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Nigeria
2. Chemical Sciences Department, Olabisi Onabanjo University, Ago-Iwoye, Nigeria
3. Department of Chemistry, University of the Free State, Bloemfontein, South Africa
4. Department of Pure and Industrial Chemistry, University of Nigeria, Nsukka, Nigeria
5. Chemistry Department, Vaal University of Technology, Vanderbijlpark, South Africa