Browsing by Author "Usman, N.L."

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    Aqua regia and ethylenediaminetetracetic acid (EDTA) trace metal levels in agricultural soil
    (Department of Chemistry, Faculty Of Natural And Applied Sciences, Nasarawa State University, Keffi, 2013-09-24) Tukura, Bitrus Wokhe; Usman, N.L.; Mohammed, H.B.
    Soil samples were collected from irrigation farmlands along the bank of Mada River and analysed for aqua regia and ethylenediaminetetracetic acid (EDTA) extractable trace metal (Cd, Cr, Cu, Pb, Zn Ni, Fe and Mn) concentrations. Water samples at source were also collected for analysis. Metal levels were quantified using atomic absorption spectrometry (AAS). Aqua regia and EDTA extractable Fe and Cd concentrations were the highest and lowest, respectively. The highest and lowest aqua regia and EDTA trace metal concentrations were recorded at sites 1 and 3, respectively. Aqua regia trace metal levels were generally higher than that of EDTA, but below the critical values for irrigation soil. Soils were extremely enriched with Cd (153 – 289), and deficient in Fe (0.5 – 1.0) contents. Fe Kd was generally the highest (21.45 – 44.35 kgl-1) and Zn (0.03 – 0.08 kgl-1) the lowest. Higher total metal contents result in a lower proportion of metal being sorbed, because potential absorption sites are filled in decreasing order of affinity. Strong and positive correlations existed for Cr/Zn (0.9879) and Cu/Ni (0.8077) at Site 1, Cu/Ni (0.9229) and Pb/Pb 0.9581) at Site 2, and Ni with Cr (0.9440) and Cu (0.8153) at Site 3. Significant correlations for soil-water indicated contributions of irrigation water to total metal contents in soil.
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    Translocation of Trace Metals in Vegetable Crops Grown on Irrigated Soil along Mada River, Nasarawa State, Nigeria
    (Department of Chemistry, Faculty Of Natural And Applied Sciences, Nasarawa State University, Keffi, 2012-04-16) Tukura, Bitrus Wokhe; Anhawange, B.A.; Mohammed, Y.; Usman, N.L.
    Trace metals play an important role in the metabolic pathways during the growth and development of plants, when available in appreciable concentration. Pepper and okra vegetable crops were collected from irrigated farmlands along Mada River and separated into roots, stems, leaves and fruits. Concentrations of cadmium, copper, chromium, iron, nickel, lead, zinc and manganese were analyzed using atomic absorption spectrometry. Biological concentration factors (BCF), transfer factor (TF) and, biological accumulation coefficient (BAC) were calculated for assessment of mobility of trace metals from soilroot, root-shoot and soil-shoot, respectively. Mobility index (MI) was also calculated for roots-stems, stems-leaves and stems-fruits. The results showed concentration dependent variables of heavy metal levels between vegetables. Accumulation gradient of each crop component varies according to nature of the vegetable. MI of metals among components in okra exceeded in roots-stems and the least in stems-fruits. MI for the stems-leaves and roots-stems in pepper were the highest and lowest, respectively. Cr was the most mobile metal and Ni the least. TF and BAC values for Cd in okra and pepper were high. TF, BAC and BCF values for trace metals in okra at farm B were higher than in pepper.