Determination of Micro-amount and Trace Gold in Geological Samples by Chemical Vapor Generation-non-Dispersive Atomic Fluorescence Spectrometry

Samples of gold were dissolved by aqua regia. Volatile substances were produced by using special gold sensitization reagent in boron hydrate-acid system and were loaded into atomic fluorescence spectrometry (AFS) to determine the gold atomic fluorescence signal. Signals were twenty times stronger than other methods after optimized the parameter of instrument and chemical vapor generation. Meanwhile, this method reduced interference of coexistent ions during chemical vapor generation. The method has been applied to the determination of micro-amount and trace of gold in geological samples with high sensitivity, low detection limit (0.23 ng/g), small matrix effect and rapid determination. The accuracy of the method was -0.004-0.02 (ΔlgC, n=12) with precision of 2.62%-8.79% (RSD, n=12). The results are in agreement with certified values of first grade national standard reference materials.