Chapter 7 Drugs Kendall/Hunt

Chapter 7 Drugs and Crime A drug is a natural or synthetic substance designed to affect the subject psychologically or physiologically. “Controlled substances” are drugs that are restricted by law. The Controlled Substances Act is a law that was enacted in 1970; it lists illegal drugs, their categories, and penalties for possession, sale, or use. Kendall/Hunt

Controlled Substances Act Chapter 7 Controlled Substances Act Schedule I—high potential for abuse; no currently accepted medical use in the U.S. Examples: heroin (diacetylmorphine), LSD, marijuana, ecstasy (MDMA) Schedule II—high potential for abuse; currently accepted medical use with severe restrictions; Examples: cocaine, morphine, amphetamines (including methamphetamines), PCP, Ritalin Schedule III—lower potential for abuse than the drugs in I or II; currently accepted medical use Examples: intermediate-acting barbiturates, anabolic steroids, ketamine, codeine Schedule IV—low potential for abuse relative to drugs in III; currently accepted medical use Examples: stimulants and depressants including Valium, Xanax, Librium, phenobarbital Schedule V—low potential for abuse; currently accepted medical use in the U.S.; Examples: over-the-counter medications Kendall/Hunt

Stimulants: elevate a person’s mood temporarily, relieve some symptoms of depression, usually not physically addictive but can cause psychological dependence. Examples: cocaine, and methamphetamine. Depressants: relieve anxiety, nervousness and restlessness; highly addictives; sudden withdrawal can be fatal. Examples: barbiturates, alcohol, diazepam (valium), quaaludes. Hallucinogens: cause auditory and visual hallucinations. Examples: marijuana, LSD, PCP, mescaline (peyote), psilocybin (mushrooms) Narcotics: sleep-inducing, central nervous system depressants; derived from the opium poppy. Examples: opium, morphine, heroin, methadone, codeine, oxycodone

Human Components Used for Drug Analysis Chapter 7 Human Components Used for Drug Analysis Blood Urine Hair Gastric contents Bile Liver tissue Brain tissue Kidney tissue Spleen tissue Vitreous humor of the eye Kendall/Hunt

Physicians’ Desk Reference Chapter 7 Physicians’ Desk Reference PDR—A Physicians’ Desk Reference is used to identify manufactured pills, tablets, and capsules. It is updated each year. This can sometimes be a quick and easy identifier of the legally made drugs that may be found at a scene. The reference book gives a picture of the drug and states whether it is prescription, over-the-counter, or a controlled substance; it gives more detailed information about the drug as well. Kendall/Hunt

Screening Tests: add one or more chemical reagents to a suspected drug and observe a color change. Ex: marijuana turns purple, cocaine turns turquoise. Screening tests are not used to confirm the presence of a specific drug because there could be many drugs that give similar positive reactions. Separation Tests: Most illicit drugs are diluted with other substances. Gas chromatography can separate the pure drug from the cutting agents (sugars, powders, etc.) Confirmation Tests: Mass spectrometry confirms specific drugs

Drug Identification, continued Chapter 7 Drug Identification, continued Screening or presumptive tests only tell that the drug is possibly present. Confirmatory tests tell that the drug is positively present. (Screening tests are easier, cheaper, and quicker to use.) Kendall/Hunt

Chapter 7 Chromatography A technique for separating mixtures into their components Includes two phases—a mobile one that flows past a stationary one The mixture interacts with the stationary phase and separates Types: Paper Thin-layer (TLC) Gas (GC) Pyrolysis gas (PGC) Liquid (LC) High-performance liquid (HPLC) Column Kendall/Hunt

Paper Chromatography Stationary phase—paper Chapter 7 Paper Chromatography Stationary phase—paper Mobile phase—a liquid solvent Capillary action moves the mobile phase through the stationary phase. Kendall/Hunt

Thin-layer Chromatography Chapter 7 Thin-layer Chromatography Stationary phase—a thin layer of coating (usually alumina or silica) on a sheet of plastic or glass Mobile phase—a liquid solvent Kendall/Hunt

Chapter 7 Retention Factor (Rf) This is a number that represents how far a compound travels in a particular solvent. It is determined by measuring the distance the compound traveled and dividing it by the distance the solvent traveled. If the Rf value for an unknown compound is close to or the same as that for the known compound, the two compounds are likely similar or identical (a match). Kendall/Hunt

Gas Chromatography Phases Stationary—a solid or a Chapter 7 Gas Chromatography Phases Stationary—a solid or a viscous liquid that lines a tube or column Mobile—an inert gas like nitrogen or helium Analysis Shows a peak that is proportional to the quantity of the substance present Uses retention time instead of Rf for the qualitative analysis Kendall/Hunt

Confirmatory Tests: Spectroscopy Chapter 7 Confirmatory Tests: Spectroscopy Spectroscopy—the interaction of electromagnetic radiation with matter Spectrophotometer—an instrument used to measure and record the absorption spectrum of a chemical substance Kendall/Hunt

Infrared Spectrometry Chapter 7 Infrared Spectrometry Material absorbs energy in the near-IR region of the electromagnetic spectrum Compares the IR light beam before and after it passes through a transparent sample Result—an absorption or transmittance spectrum Gives a unique view of the substance; like a fingerprint Kendall/Hunt

Chapter 7 Mass Spectrometry Gas chromatography has one major drawback: It does not give a specific identification. Mass spectrometry cannot separate mixtures. By combining the two (GC-MS), constituents of mixtures can be specifically identified. Kendall/Hunt

Mass Spectra Each molecular species has its own unique mass spectrum. Chapter 7 Mass Spectra Each molecular species has its own unique mass spectrum. Kendall/Hunt