Forensic Analysis of Drugs: Drug Categories

1. Forensic Analysis of Drugs:Drug Categories

2. Drug = a natural or synthetic substance that is used to produce physiological or psychological effects • Why important to forensics? • 75+ % of evidence analyzed in crime labs is drug related • Huge expansion in analytic capabilities of drug labs to process these samples

3. Drug Dependence • Psychological • Emotional need (can be severe) • Craving • Physical • Brought on by regular use • Experience withdrawl symptoms when abruptly stopped (can result in death)

4. Narcotics • Def: analgesic/pain killing substance that depresses vital body funtions (BP, pulse, breathing) • Regular use results in physical dependence • “narcotic” often used incorrectly for any drug that is socially unacceptable • Derivatives of opium

5. Narcotics • Morphine – extracted from opium • Heroin • react morphine with acetyl anhydride • water soluble (IV use), 35% pure (lots of fillers!) • Codeine • In morphine but usually synthesized in lab • 1/6 the strength of morphine • Fentanyl • 100x more potent than morphine

6. Narcotics- not derived from opium but considered opiates • Methadone – related to heroin and used to treat addiction • Prescription pain killers • Percocet • often abused due to addictive nature

7. Hallucinogens • Def: substance that induces changes in mood, attitude, though or perception • Can cause psychological dependence • Many derived from natural substances

8. Hallucinogens • Marijuana • From Cannabis plant • Most widely used illicit drug • Active ingredient THC (2-20%) • Medical uses: glaucoma, muscle relaxant, nausea

9. Hallucinogens • Peyote • From cactus • Used by American Indians to induce religious experience • Magic Mushrooms • Psilocybin = similar to serotonin • High doses can impair cognition

10. Hallucinogens • LSD = lysergic acid diethylamide • From ergot (fungus that attacks grasses) • Very potent • Flashbacks and psychotic episodes even after discontinued use • PCP = phencylidine • Synthetic – made from toxic chemicals • Often mixed with other drugs • LT use can lead to suicide, schizophrenia

11. Hallucinogens • MDMA/Ecstasy • Synthetic • Originally patented as appetite suppressant • Severe adverse reactions = severe anxiety, paranoia, etc

12. Depressants • Def: substance used to depress the functions of the CNS. Calms irritability and may induce sleep. • Most can cause physical dependence

13. Depressants • Alcohol • Most widely used legal drug • High levels can cause fatal depression of circulatory and respiratory functions • Barbiturates • Powerful sedatives • Used in medical profession • Quaaludes have similar effect

14. Depressants • Tranquilizers • Cause relaxation w/o inducing sleep • Valium and other anti-anxiety meds • Glue sniffing, huffing, etc

15. Stimulants • Def: substance taken to increase alertness. Increase BP, breathing, pulse • Some cause psychological dependence

16. Stimulants • Amphetamines • Meth, phen-phen • Increases alertness but over time causes depression, anxiety and paranoia • Cocaine/Crack • Extracted from leaves of coca plant

17. Anabolic Steroids • Chemically related to testosterone • Promote muscle growth • Can cause “roid rage”, depression, infertility, premature stop in bone growth

18. Drug Schedules • 5 schedules based on potential for abuse/dependence and medical value • Schedule I • high potential for abuse/dependence • low medical value • Schedule V • low potential for abuse/dependence • high medical value

19. Forensic Analysis of Drugs:Drug Testing

20. Most drugs are composed of a mixture of the active ingredient and fillers/additives. • This “cutting” is used to stretch the drug so that more money can be made. • Common additives include sugar, starch, and quinine.

21. Scheme of Analysis for Determining the Identity of a Drug • Screening Tests • Used to reduce the number of possibilities to a manageable number • Quick tests but non-specific in nature. Must be followed up with confirmation tests. • Confirmation Tests • Tests used to specifically identify a substance.

22. Screening Tests • Color Tests • Drug turns a characteristic color when brought into contact with certain chemicals.

23. Screening Tests • Microcrystalline Tests • Several crystals of the drug are examined under a microscope and a preliminary identification is made based on the shape and color of the crystals. • Impurities can alter the crystals and throw off results.

24. Screening Tests • Chromatography • Used to separate mixtures based on the preferential affinity (attraction) to the stationary phase or the moving phase. • Used to purify the drug by separating it from the additives/fillers • Compare Rf values to controls to make an ID Formula: Rf = distance individual spot moves distance solvent (moving phase) moves

25. Screening Tests • Chromatography

26. Confirmation Tests Drugs must be PURE in order to perform these tests

27. Confirmation Tests • Infrared (IR) Spectrophotometry • Electromagnetic radiation is absorbed differently by chemical bonds in a substance • Provides a unique chemical fingerprint

28. Confirmation Tests Mass Spectrophotometry • High energy electrons are shot at a substance breaking the bonds and creating smaller fragments. • Provides a unique chemical fingerprint • Often used in combination with gas chromatography (called GS-MS; gas chromatography-mass spectrophotometry) • GC- separates drug from impurities • MS- provides unique chemical ID based on patterns of fragmentation

29. Mass Spectrophotometry

30. Analysis of Marijuana • Different analysis due to botanical nature • Combination of 2 tests provides conclusive results 1) a specific color test 2) microscopic analysis to look for cystolithic hairs (aka “bear claws”) on the leaf