Determination of Trace Thallium by FAAS after Solid Phase Extraction and Preconcentration onto Natural Analcime Zeolite Modified with Neothorin

The Thallium was separated by solid phase extraction on natural Analcime Zeolite modified with Neothorin followed by elution and flame atomic absorption spectrometric detection and applied as a separation and detection method for Thallium in water. Extraction efficiency and the influence of sample matrix, flow rate, pH, and type and minimum amount of stripping acid were investigated. Solution of Thallium passed through a glass column packed with 1g of the sorbent material, at pH 9.0, and Thallium eluted with 2 M HNO3 at a flow rate of 2.0 ml min-1. A 0.5 ppb detection limit for the preconcentration of aqueous solution of Thallium was obtained. The relative standard deviation (RSD) for eight replicate determination at the 2.5 μg/ml Thallium level was 1.2%.The calibration graph using the preconcentration system was linear from 0.2 to50μg /ml in final solution with a correlation coefficient of 0.9994.This method was successfully applied for determination of Thallium in various samples.