In the analysis of solids, often the first step is to get the analyte into solution in some form. Sometimes, solids are heated in the presence of acids (acid digestion) or molten salts (sample decomposition through fusion according to this source). These methods combined are call "Aufschluss" in German (roughly translated unlocking). There is a joke in the qualitative analysis teaching lab that for particularly difficult samples, you use the "Assistenten Aufschluss", i.e. you have to cheat and beg the T.A. to tell you what is in your sample.
Is there a technical term in English or in other languages?