<prompt> Gun powder in hand during gun-shot residue is collected using:-Paraffin waxBenzidineAcid phosphataseSulfur  <response>: Paraffin test aka dermal nitrate test is an absolete test, uses melted paraffin on the surface of hand. The wax is removed its inner surface is treated with diphenylamine or diphenyl benzidine reagent. A blue color develops when residue is present. 