Spectrum™ Ammonium Hydroxide, 10 Percent (w/v) NH3 Solution, (U.S.P. Test Solution) is a solution of ammonia in water. Aqueous ammonia, as it′s otherwise known is used as a complexant and base in qualitative inorganic analysis. It becomes a deep blue color with copper solutions. Used to dissolve silver oxide residues, such as the ones formed from Tollens′ reagent, it is also commonly used in numerous cleaning agents, such as window cleaning formulas as well as a complexant that is manufactured to parts-per-billion trace impurities and has been used in the semiconductor industry to dissolve heavy or precious metal components.