1. Department of Chemistry, University of Nairobi, Nairobi, Kenya
2. Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Dortmund, Germany
3. School of Pure and Applied Sciences, University of Embu, Embu, Kenya
4. Department of Chemistry, Federal University Lafia, Nasarawa State, Nigeria
5. Department of Pharmaceutical Biology, Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University, Mainz, Germany