Wednesday, July 24, 2019

Drug profiling assignment Essay Example | Topics and Well Written Essays - 2000 words

Drug profiling assignment - Essay Example Forensic scientists employ several tests and techniques to provide evidence needed for the case. Analysis of samples is necessary to identify, quantify and drug profiling. The materials previously collected, 100 grams of white powder, the trace samples from the clothing of the suspects, the cling film and the mirror will all be subjected to analysis. Prior to the presumptive tests, physical description and sampling will be done. The physical characteristics such as texture, powder particle size, color, odor, taste and weight will be physically defined before a sample for analysis will be secured. It will be weighed and thoroughly homogenised, before a sample was taken. Presumptive analysis will provide the identification of the white powder collected from the table. Trace samples from the suspects’ clothing can directly be analyzed using confirmatory tests. Colour test will bring initial data for the powder’s identity. Specific color changes give the positive result for the powder’s identity. An intense blue-violet color when the powder is made to react with 1% cobalt acetate, and 5% isopropylamine in methanol of Dillie-Koppanyi test will identify it as a barbiturate. Marquis test using dilute solution of methanal in sulphuric acid can give two types of results; if the colour changed to purple, the powder is heroin-based, if the test however yields an orange-brown colour, the powder is an amphetamine. Treating it with a Duquenois-Levine test reagent and a purple colour resulted, the powder is positive as marijuana. In Scott test, in which a solution of cobalt chloride is added in a 50:50 mixture of water and glycerol, a blue c olour positively identifies cocaine. This positive result can be confirmed by adding concentrated hydrochloric acid, liquid goes pink and then adding chloroform the blue reappears in the chloroform layer. Blue-purple in reaction with

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