[1] Fed Univ Dutsin Ma, Chem Dept, Katsina, Nigeria
[2] Fed Univ Dutsin Ma, Ind Chem, Katsina, Nigeria
[3] Fed Univ Dutsin Ma, Geog Dept, Katsina, Nigeria
[4] Ahmadu Bello Univ, Chem Dept, Zaria, Kaduna, Nigeria
[5] Ahmadu Bello Univ, Geol Dept, Zaria, Kaduna, Nigeria