Separation and Preconcentration of Trace Amounts of Manganese and Nickel from Natural Water Samples by a Diimine Derivative Schiff Base-Coated Silica-Gel Minicolumn

Figure 3

Effect of amount of diimine derivative Schiff base (ligand) on the recovery of Ni (II) and Mn (II) on column. Concentration of standard solution Ni (II) and Mn (II), 25 μg L⁻¹, pH = 4, sample flow rate, 5 mL min⁻¹. Eluent type, 5 mL mixture of nitric acid 5 mol L⁻¹, and methanol (1 : 1). Elution flow rate, 2 mL min⁻¹.