Gun powder in hand during gun-shot residue is collected using:-: (A) Paraffin wax, (B) Benzidine, (C) Acid phosphatase, (D) Sulfur
Answer is A. * 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.