The invention discloses an analytic method of trace gold contained in composition
brass. The analytic method of the trace gold contained in the composition
brass is characterized by comprising the following steps of:
grinding a sample to be powdery, weighing 1-10 grams, placing into a
beaker, and adding a
nitric acid solution at the volume ratio of 50%; after reaction, heating, and boiling; dissolving during micro-boiling for about 10 minutes, and taking out for cooling; filtering through a quantitative low-speed
filter paper, cleaning the
beaker by using deionized water, and totally transferring cleaning liquid to a
filter funnel; then cleaning depositions for three times by using the deionized water, and transferring the
filter paper and filter residues together into the
beaker used for originally dissolving the sample; adding
aqua regia, and heating; dissolving during micro-boiling till the volume of the solution is about 5-10mL, and taking out for cooling; carrying out dry filtering by using a
volumetric flask with the constant volume of 25-1000mL and a core funnel; measuring the
light absorbance of filter liquor by using an air-
acetylene flame atomic absorption spectrophotometer; and computing the
mass concentration of the gold according to a standard working curve method. The method disclosed by the invention has the advantages of ideal separation effect, accurate analytic result, good reproducibility and easiness and fastness for operation; and compared with the traditional fire
assay, the method has the advantages of cost conservation, equipment, namely a high-temperature furnace, a cupellation furnace, and the like, conservation,
lead pollution prevention and environment friendliness.