Evaluation of lithium separation by dispersive liquid–liquid microextraction using benzo-15-crown-5

In this article a dispersive liquid–liquid microextraction method was applied for evaluation of lithium separation from aqueous solution. Benzo-15-crown-5 (B15C5) was used as a chelating agent prior to extraction. An appropriate mixture of disperser solvent and extraction solvent were added rapidly into the aqueous sample containing lithium ion; as a result, a cloudy solution was formed which consisted of fine droplets of extraction solvent dispersed entirely into aqueous phase. The mixture was centrifuged and the lithium complex with B15C5 was sedimented at the bottom of the conical sample holder. Then, 2.0 mL of enriched phase containing lithium complex was used for determination of lithium ion by flame atomic absorption spectrometry. The conditions for the microextraction performance were investigated. Under the best optimized conditions, the accepted recovery factors for the lithium obtained, ranged from 37.24 to 99.63 %. Furthermore, high preconcentration factors (7.46–19.93) were also achieved. The relative standard deviation for three replicate measurements of 0.127 mg L−1 of lithium was 2.83 %.