W. Y. MA, Q. HUI, M. XUE, W. X. JI and D. Y. CHEN
A resonance ionization mass spectrometric technique for the ultratrace determination of Au in geogas samples was developed. A three-step excitation scheme leading to an autoionizing state was used for detecting the Au content of 60 geogas samples combined with a graphite furnace electrothermal atomizer. In order to increase the selectivity and detection efficiency, a linear time-of-flight mass spectrometer was built and tested. The experimental results are in good agreement with those obtained by neutron activation analysis. The study of the Au distribution in geogas is of great interest in prospecting for gold deposits.