Determination of trace gold in geological samples by Z-2000 polarized Zeeman graphite furnace atomic absorption spectrometry

Trace gold was determined by means of atomic absorption spectrometer with Z-2000 polarized Zeeman graphite furnace after the samples have been burned,dissolved by aqua regia,collected by polyurethane foam materials and desorbed by thiourea. The choice of graphite tube,drying,atomization,gray,and purification of temperature and time were discussed,as well as the factors that affected the efficiency of gold's release and the conditions that was compared with emission spectroscopy mothod were studied. The detecting limit of which was 0.17ng / g,the precision was less than 8.0%.This method has been verified by the analysis of the nationa standard samples ,and the results were in line with the standard value.