Separation and preconcentration of rare earth elements in geological materials using used green tea leaves and their determination by ICP-OES

A simple method has been developed for the separation and preconcentration of Rare Earth Elements (REE's) in different types of geological materials using the sorption property of the used green tea leaves (UGTL's). The elemental determinations have been carried out by Inductively Coupled Plasma-Optical Emission Spectrometer. A number of parameters, like pH, volume, concentration of REE's, sodium fluoride, matrix element effects and amount of the UGTL have been optimised for the quantitative recovery of REE's. Separation of REEs has been achieved by stirring the sample solution (similar to 200 ml at pH 3) with 1 g of the used green tea leaves powder and 0.12 M NaF. After keeping over night, the filtered mass was ignited in a muffle furnace at 600 degrees C and taken in dilute nitric acid for ICP-OES determination. The method was validated by analysing the standard reference materials SY-3 (Syenite, CCRMP) and NCSDC 86318 and the results obtained are in good agreement with the certified values. The accuracy of the method is 5% for most of the elements and the precision is characterised by 2-5% RSD.