Extraction of Trace Amount of Lithium from Natural Brines and Determination by Flame Photometric Method

Document Type : Research Article

Authors

Department of Chemistry, Payame Noor University, PO Box 3697 19395 Tehran, I.R. IRAN

Abstract

In this research, the formation constant (Kf) of some metallic ions complexes with 2,2- pyridine 2,6- diyil bis(nitrilo (E) methyliden Schiff base ligand in ethanol at 25°C have determined coductometrically, and the data showed good complex formation with Li+ ion. Thus this is used for modification of C18 disk for solid phase extraction (SPE) of Li+ from waters and brines samples and determination by flame photometer. Since the direct determination of lithium in brines by flame photometry is difficult, because of a large amount of interferences ions and high viscosity of the sample, thus the samples were diluted extremely. Then lithium has extracted by ligand modified C18 disk and determination by flame photometer. In the optimum condition, pH = 8, 4.0 mg of ligand, 5.0 mL 0.3M perchloric acid as an elution buffer, the detection limit of the method was 0.74 µg/L. The method has used for determination of trace amount of lithium ion in natural brines successfully.

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