This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mechanical injuries, Subject name: Forensic Medicine
Gunshot residue on hands can be detected by - 
Select and explain. 
A. Phenolphthalein test, B. Dermal nitrate test, C. Benzidine test, D. Hydrogen activation analysis
B: Dermal nitrate test
Answer: B: Dermal nitrate test 
Explanation: The synopsis of forensic medicine & toxicology ;Dr k.s narayan reddy ; 28th edition ; pg.no . 136 Paraffin test or dermal nitrate test is done to detect nitrates and nitrites .Melted paraffin is brushed on hand ,the wax is removed & the inner surface of wax cast treated with diphenylamine or diphenylbenzedine reagent ,a blue colour developes where residue is present ,but it is obsolete .