GF-AAS Determination of Pico-Trace Amounts of Gold Using Solid State Sample Introduction

It is reported that traces of gold in geochemical samples were preconcentrated by adsorption on tributylphosphate (TBP) coated polyurethane plastic foam (PUPF),and determined by GF-AAS with re-shaped thermal decomposition graphite tube.The PUPF with the adsorbed gold ion was introduced directly into the graphite tube and gold adsorbed was determined by AAS.Application of direct sample introduction of the PUPF with adsorbed auric ion gave specific features in 2 aspects:① loss of gold in the desorption procedure was avoided;and ② the value of detection limit was lowered to pico-trace level.Test for precision was made at 3 concentration levels,giving values of RSD (n=11) ≤3.6%.Results of recovery test obtained were in the range from 102%-107%.Detection limit of this method was found to be 10 pg·g-1.The accuracy of the proposed method was checked by analyzing a CRM (GBW 07242) sample for its gold content,results obtained were in consistency with the certified value.