Solid phase extraction of lithium ions from water samples using K-birnessite with layer-structure material form (KBRLSM)

Abstract

Layer-structure materials have attracted considerable interest for the removal, separation, and preconcentration of trace metals in analytical and environmental chemistry. In the present work, we developed a separation and preconcentration method for lithium ions from water samples using K-birnessite with layer-structure material (KBRLSM) form. The experimental parameters that affected the extraction efficiency of the method such as pH, flow rate and volume of the sample solution, concentration of eluent, amount of adsorbent, effect of common matrix ions, and capacity of adsorbent were investigated and optimized. The adsorbed Li ions on KBRLSM were eluted with 5 mL of 1 mol L−1 HCl solutions and their concentrations were determined by high resolution-continuum source flame atomic absorption spectrometry. The adsorption isotherm studies indicate that the adsorption of Li ions follows both the Langmuir and Freundlich isotherms. The Langmuir monolayer adsorption capacities (qmax) were estimated as 2.77 mg g−1. A constant of the energy (KL) for Li was calculated as 0.35 L g−1. The optimum pH value for quantitative sorption of Li ions was found between 5.0 and 7.0. The preconcentration factor was found as 40 for 200 mL aqueous solution containing 5 μg Li ions. The developed method was successfully applied to some water samples.