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FORENSIC SCIENCE Toxicology. Today is the last day for drug assignments. You need to turn in today: All drug notes (3- Intro, Drugs, Testing) 3 drug labs ( Urine analysis- table 1, Drugs & Money- table 3, Spot test- table 2) Spectrograph review. Project. Two people per group
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Today is the last day for drug assignments • You need to turn in today: • All drug notes (3- Intro, Drugs, Testing) • 3 drug labs ( Urine analysis- table 1, Drugs & Money- table 3, Spot test- table 2) • Spectrograph review
Project • Two people per group • Case must involve DRUGS, POISONS, ARSON
Forensic File #3 • You have been asked to determine the difference between aspirin (salicylic acid) and tylenol, both of which are white powders. • What would you use to tell the difference? Think back to the lab from yesterday (HCl, water, FeCl, Universal indicator). What would this tell you?
Forensic File #3 • What would you use to tell the difference? Think back to the lab from yesterday (HCl, water, FeCl, Universal indicator). What would this tell you? • Use Universal Indicator- this will tell you the difference between acids and bases… aspirin is an ACID
Today’s assignments • Pretest 0-30: You do the webquest on computer cart • Pretest 40-60: You do the narc lab on table 1 • Pretest 70-100: You do drug residue lab on table 2
Drug-Control Laws • Controlled substance act, Title II or the Comprehensive Drug Abuse Prevention and Control Act of 1970 • Legal foundation of the Government’s fight against abuse of drugs and other substances • A consolidation of numerous laws regulating the manufacture and distribution of narcotics, stimulants, depressants, & hallucinogens
Drug Identification • The challenge is that the unknown substance may have one of a thousand or more commonly encountered drugs and the investigator may have only a limited supply of the evidence to test
Screening tests • Primary function is to eliminate some drugs from consideration • Also referred to as PRESUMPTIVE tests since they don’t actually identify the substance • These include spot tests (color change test) and microcrystalline test
Screening tests or presumptive tests Color tests Microcrystalline test--a reagent is added that produces a crystalline precipitate which are unique for certain drugs. Confirmation tests Chromatography Spectrophotometry Mass spectrometry DRUG IDENTIFICATION
Presumptive Color Tests: Spot tests • Often done on a spot plate or in a test tube • Normally destroys the sample • No spot test is specific for a particular drug, so a negative test is a good indicator for ruling something out
Microscopic tests • Morphology- most commonly used with plant matter such as marijuana • Look for botanical features associated with plant
Microcrystalline test • Involves dissolving the sample in a suitable solvent, filtering and adding a precipitating agent to promote crystallization • The size and shape of the crystals are highly characteristic of the drug
Chromatography • Thin layer or gas chromatography used • Comparison of the Rf or retention-time values between questioned and known drugs
Probable or conclusive identification tests • Spectrophometry or mass spectroscopy • Data can separate a complex mixture and then unequivocally identify each substance in the mixture • Match the spikes to known substances to identify
Blood Urine Vitreous Bile Liver tissue Brain tissue Kidney tissue Spleen tissue Human Analysisfor Drugs