Method for separating silver in gold-palladium-platinum testing process

The invention relates to a method for separating silver in gold-palladium-platinum testing process. The method comprises the following steps: putting composited silver particles into a flask, adding concentrated nitric acid, heating to dissolve until nitric acid smoke disappears and a solution is colorless, and taking the flask down; adding concentrated hydrochloric acid to generate silver chloride precipitates, further adding the concentrated hydrochloric acid until the silver chloride precipitates are completely dissolved, and heating to evaporate the solution until the solution is dry; and heating 1-3mL of aqua regia until the aqua regia boils, flushing watch glass and the wall of the flask with water, boiling until the solution is clear, cooling, and carrying out solid-liquid separation. As the content of silver contained in the gold-palladium-platinum testing liquid is too high, the blockage of a feeding system as well as the salification of a rectangular tube are caused in the testing process of an ICP-AES or ICP-MS instrument, and the stability of the instrument is influenced. According to the method, by adequately utilizing the properties of silver and silver chloride, gold, palladium and platinum are dissolved in evaporation and concentration processes, and the silver chloride is slowly precipitated, so that the packaging to the gold, the palladium and the platinum is avoided, the separation of the silver in the testing liquid is realized, and the testing requirements of the instrument are met.