Chemical Treatment Unit 0.0 / 5 ? CriminologyForensic StudiesUniversityOther Created by: AshleeCreated on: 01-05-15 18:18 What are the two exhibit types? Porous and non-porous 1 of 17 Name some porous materials commonly treated? Letters, clothes, newspapers, money, paper 2 of 17 Name some non-porous materials commonly treated? Credit cards, weapons, guns, plastic bags 3 of 17 What is the ISO standard for lab work? ISO 17025 4 of 17 What are ISO standards? Nationally recognised; recognition of competence; quality management system; transparent system of work; everyone follows same standards; policies and procedures 5 of 17 Name some light sources used to recover evidence? Crime lite; schott light; laser; coloured light; fluorescence 6 of 17 Why is fluorescence used? Materials absorb light on certain wavelengths/ colours and re-emit them at a lower intensity so they become visible 7 of 17 What are the 2 types of different treatment? Destructive and non-destructive 8 of 17 What is looked for when examining an exhibit at CTU? Constituents of sweat - amino acid, salt, water, fats/lipids - and other contaminants like drugs, food and paint 9 of 17 Name the different treatments used. Superfume; ninhydrin; DFO; ethylcyanoacrylate/superglue; fluorescent dyes; vacuum metal deposition/VMD; physical developer/VD; document analysis; protein stains; powder suspension 10 of 17 What is ninhydrin? Chemical used which makes marks visible - high contrast purple 11 of 17 What is DFO? Makes fingerprints glow bright yellow when lit with a blue/green light 12 of 17 What is ethylcyanoacrylate? Superglue - reacts with traces of lipids, fatty acids and proteins to leave sticky white material that forms along ridges of fingerprints 13 of 17 What is vaccum metal deposition or VMD? Thin film coatings of zinc and gold evaporate onto non-porous substrates making them visible 14 of 17 What are 2 protein stains used? Coomassie blue and Crowle's double stain 15 of 17 How do protein stains work? Reacts with proteins in fingerprints/skin etc.. 16 of 17 Name some powder suspensions. Aluminium powder; black or jet black magnetic powder and black granular powder 17 of 17
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