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1 FORENSIC SCIENCE Toxicology
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Drug Assignments u Today is the last day for DRUG ASSIGNMENTS 2
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Forensic Files, 4-8 u What is the difference between stimulants and hallucinogens? 3
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Today is the last day to turn in: u All drug notes (3- Intro, Drugs, Testing) u 2 drug labs: Drugs & Money- table 3, Spot test- table 1) u Spectrograph review u Technology assignment: Mouse Party or Drug Dosage Gizmo 4
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Forensic File #2 u You have been asked to determine the difference between aspirin (salicylic acid) and tylenol, both of which are white powders. u 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? 5
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Today’s assignments u Alcohol notes from blog u BAC lab u BAC calculations u Start Crime 360- Gilpin Court 6
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Forensic File #3 u 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? u Use Universal Indicator- this will tell you the difference between acids and bases… aspirin is an ACID 7
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Project u Two or three people per group u Case must involve DRUGS, POISONS, ARSON 8
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Drug-Control Laws u Controlled substance act, Title II or the Comprehensive Drug Abuse Prevention and Control Act of 1970 u Legal foundation of the Government’s fight against abuse of drugs and other substances u A consolidation of numerous laws regulating the manufacture and distribution of narcotics, stimulants, depressants, & hallucinogens 9
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Drug Identification u 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 11
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Screening tests u Primary function is to eliminate some drugs from consideration u Also referred to as PRESUMPTIVE tests since they don’t actually identify the substance u These include spot tests (color change test) and microcrystalline test 12
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13 DRUG IDENTIFICATION Screening tests or presumptive tests u Color tests u Microcrystalline test-- a reagent is added that produces a crystalline precipitate which are unique for certain drugs. Confirmation tests u Chromatography u Spectrophotometry u Mass spectrometry
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14 Presumptive Color Tests: Spot tests u Often done on a spot plate or in a test tube u Normally destroys the sample u No spot test is specific for a particular drug, so a negative test is a good indicator for ruling something out
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Presumptive Tests for drugs 15 TestColor changeIndicates the presence of MarquisPurple Orange-brown In presence of most opium derivatives In presence of amphetamines & methamphetamines Dillie-KoppanyiViolet-blueMost barbituates Duquenois-LevinePurpleMarijuana Van UrkPurplePresence of LSD ScottBluePowdered cocaine
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Microscopic tests u Morphology- most commonly used with plant matter such as marijuana u Look for botanical features associated with plant 16
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Microcrystalline test u Involves dissolving the sample in a suitable solvent, filtering and adding a precipitating agent to promote crystallization u The size and shape of the crystals are highly characteristic of the drug 17
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Chromatography u Thin layer or gas chromatography used u Comparison of the Rf or retention-time values between questioned and known drugs 18
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Probable or conclusive identification tests u Spectrophometry or mass spectroscopy u Data can separate a complex mixture and then unequivocally identify each substance in the mixture u Match the spikes to known substances to identify 19
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21 Human Analysis for Drugs u Blood u Urine u Vitreous u Bile u Liver tissue u Brain tissue u Kidney tissue u Spleen tissue
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