Where to buy aqua regia?

Answer 1

You can't buy aqua regia. It quickly decomposes after mixing, therefore must be made just before use. Aqua regia is highly corrosive, toxic,volatile and explosive when mixed with many common materials. Do not consider making aqua regia unless you know what you are doing, have produced a full risk assessment, and have taken adequate precautions. Note aqua regia must be neutralised before disposal. This is itself a highly exothermic reaction and potentially hazardous unless performed correctly.