Gun powder in hand during gun-shot residue is collected using:-
* 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.
Paraffin wax
Benzidine
Acid phosphatase
Sulfur
Ballistics