Identification and Determination of Mineral Contents in Gazelle licked soils in northern Darfur by Atomic Absorption Spectroscopy

Abstract

This study aimed to identify the distinctive features of the natural soils licked by Gazelle in Alkuma area (Northern Darfur), and to characterize and determine the type of minerals as the major attractant for Gazelle to visit these sites frequently. Samples were collected from six soil- lick fields, and were analyzed for chemical and physical properties, such as pH values, moisture content, total-water soluble solids and electrical conductivity. The minerals were extracted using the sequential extraction technique and their concentrations were determined using atomic absorption spectroscopy and flame photometry. The soil samples solutions showed high electrical conductivity values (mean 689.441ms), basic pH values (mean 7.449), different moisture content values (mean1.973%) and almost similar total water-soluble solids values (408.82mg/L). mineral content determination showed high concentrations of iron Fe, potassium K, calcium Ca, sodium Na and magnesium Mg. Cobalt was absent in all samples except No.(8 and 9). Lead was not detected in any sample. Chromium, manganese nickel and copper showed considerable concentrations. Cadmium showed the lowest mean concentration. The quantified minerals were extracted in different steps, e.g., sodium, magnesium, Nickel, Manganese, zinc and cadmium showed significant concentrations in all fractions. Potassium and calcium were almost extracted in the first fraction and small amounts in the second fraction. Chromium, iron and cobalt ions were almost extracted in the last fraction. Results of sequential extraction showed that the mobility of elements in the order: K>Ca>Na>Mg>Fe> Mn>Zn? Ni>Cu? Cr>Cd>Co. The orders of elements mobility for the second fractions were found to be: Fe> Ca >K >Mg >Na >Mn >Zn >Ni > Cu > Cd ? Cr. The mobility of elements in third fraction was: Fe? Na> K> Mg> Ca> Ni> Mn> Cr> Zn> Cu> Cd>Co. The order of mobility of the elements in the fourth fraction was: Fe>K>Mg>Mn>Cu>Cr>Zn>Ni >Mg>Co>Cd. Pb is absent in all samples.