Study on Solid Phase Extraction and Flame Atomic Absorption Spectrometry for the Determination of Trace Gold

Abstract

A new method was developed for the separation and preconcentration of Au(III) ions based on its complex formation with 2-carboxyl-1- naphthalthiorhodanine (CNTR) loaded on graphitized carbon black as a sorbent in a cartridge. The preconcentrated ions were eluted from the cartridge by passing 2.0 mL 0.1 mol L^-1 Na₂S₂O₃ solution through the solid support and then the Au(III) contents was measured by flame atomic absorption spectrometry. Conditions for preparation of the graphitized carbon black loaded with CNTR, pH and flow rate variables were studied, as well as, the effect of potential interfering ions. A preconcentration factor of 500 was achieved under the optimum conditions. The detection limit of the method was 0.05 μg L^-1 for Au(III). The method was successfully applied to the determination of Au(III) in water and ore samples. The relative standard deviations were below 3.3 % with recoveries of 88-104 %. The determination results were agreed with that of reference method (ICP-MS method).