1. Department of Pure and Industrial Chemistry, University of Nigeria, Nsukka 410105, Enugu State, Nigeria
2. Central Science Laboratory, University of Nigeria, Nsukka 410105, Enugu State, Nigeria
3. Department of Geology, Chukwuemeka Odumegwu Ojukwu University, Awka 432107, Uli Anambra State, Nigeria
4. Faculty of Engineering and Built Environment, University of Johannesburg, Johannesburg 2092, South Africa
5. Department of Chemistry, University of Free State, Bloemfontein 9301, South Africa