Abstract: Using aqua regia as the medium, trace gold was separated from ores by a self-designed micro chromatographic column online separation and enrichment system, and measured by flame atomic absorption spectrometry. The condition of the gold and enrichment with the P₃₅₀ micro chromatographic column in the process of atomic absorption spectrometry absorbing and effusing solution were optimized. The fast adsorption and elution technology was taken with HCl solution as leacheate and Na₂SO₃ solution as the eluent. The quantification of a sample, including separation and measurement, only took one minute and overcame the defect of low sensitivity of the flame atomic absorption spectrometry. Relative standard deviation (RSD) of the method was less than 3.2% and the detection limit was 0.078 μg/g. Compared with the method of existing off-line separation and enrichment, this method shows the advantages of higher efficiency, decreased time, and lower cost. Results for the practical sample test are satisfactory.