Determination of gold in geological samples and anode slimes by atomic absorption spectrometry after preconcentration with amberlite XAD-16 resin

A method was developed for the determination of trace levels of gold in geological materials and anode slimes involving the adsorption of gold on Amberlite XAD-16 resin followed by FAAS determination after elution. The adsorption behaviour of the chloro complex of gold from hydrochloric acid solution was also investigated and the recovery of gold was found to be 95.48 +/- 0.04% at the 95% confidence level. The degree of preconcentration ranges from 10- to 75-fold for different sample volumes. The detection limit of gold was 0.046 mg l(-1). The adsorption isotherm and adsorption capacity of XAD-16 resin were investigated for gold. The adsorption isotherm was found to be of the Langmuir type and the adsorption capacity of the resin was 0.55 mmol g(-1) (108 mg g(-1)). The influence of geological matrix elements on the adsorption of gold was also evaluated. The gold contents of anode slime and a reference standard ore were determined by applying the proposed method.