Abstract
Eriochrome Black T and its magnesium complex is extracted into various organic solvents, i.e. benzene, chloroform, 1, 2-dichloroethane etc., in the presence of tetradecyl-dimethyl-benzyl-ammonium chloride. The sensitivity increases several times as much as that of aqueous phase by this extraction and calcium ion does not interfere with the determination of magnesium. The magnesium complex and ligand extracted into 1, 2-dichloroethane have absorption maxima at 560, 658 and 690 mμ with constant absorbance in the pH range from 11.2 to 12.2. The difference of absorbance at 690 mμ between the blank and sample gives the highest sensitivity for determination of magnesium. Under optimum conditions, Beer's law is obeyed at least up to 5×10-6 M magnesium in 1, 2-dichloroethane.
