The sample solution is turbid and unclear, with precipitation, and should not be placed. It is said to have a pH of 4.4. It is recommended to immediately dilute the sample quantitatively in 10% hydrochloric acid after sampling, as the gold chloride ion is stable. The hydrochloric acid concentration in this experiment is 2%, which may not be optimal. It is best to determine the hydrochloric acid concentration of the test solution through conditional experiments. The diluted test solution should be measured immediately and should not be placed, especially when the concentration of hydrochloric acid is low. The test results of the sensitive line and the sub sensitive line are basically similar, but the results of the sub sensitive line are always lower, which may be due to the interference of Co (242.5 nm) still present in the sensitive line. If a sensitive line test is used, a Co interference concentration test should be conducted. Actually, it can reduce the dilution factor and be tested with a less sensitive line. 5.4 The gold in the sample was tested using ZEEnit 700P, and the linear relationship was good, with a linear fit of 0.9999. The instrument performance was stable, and the results were accurate and reliable.