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Unit #7 Drugs, Alcohol, and Toxicology “Having sniffed the dead man’s lips, I detected a slightly sour smell, and I came to the conclusion that he had poison forced upon him.” —Sherlock Holmes, in Sir Arthur Conan Doyle’s A Study in Scarlet Unit # 7 - Drugs, Alcohol, and Toxicology 1 Drugs Students will learn: How to apply deductive reasoning to a series of analytical data. The limitations of presumptive (screening) tests. The relationship between the electromagnetic spectrum and spectroscopic analysis. The dangers of using prescription drugs, controlled substances, over-the-counter medications, and illegal drugs. Unit # 7 - Drugs, Alcohol, and Toxicology 2 Drugs Students will be able to: Chemically identify illicit drug types. Classify the types of illicit drugs and their negative effects. Discuss the federal penalties for possession and use of controlled substances. Explain the need for confirmatory tests. Unit # 7 - Drugs, Alcohol, and Toxicology 3 Drugs Describe IR, UV-VIS spectroscopy, and GC-MS Present and interpret data with graphs. Use the Physicians’ Desk Reference (PDR) to identify pills. Use technology and mathematics to improve investigations and communications. Unit # 7 - Drugs, Alcohol, and Toxicology 4 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 Controlled Substances Act is a law that was enacted in 1970; it lists illegal drugs, their category and their penalty for possession, sale or use. Unit # 7 - Drugs, Alcohol, and Toxicology 5 Controlled Substances Act Schedule I—high potential for abuse; no currently acceptable medical use in the US; a lack of accepted safety for use under medical supervision Schedule II—high potential for abuse; a currently accepted medical use with severe restrictions; abuse may lead to severe psychological or physical dependence Schedule III—lower potential for abuse than the drugs in I or II; a currently accepted medical use in the US; abuse may lead to moderate physical dependence or high psychological dependence Schedule IV—low potential for abuse relative to drugs in III; a currently accepted medical use in the US; abuse may lead to limited physical or psychological dependence relative to drugs in III Schedule V—low potential for abuse relative to drugs in IV; currently accepted medical use in the US; abuse may lead to limited physical or psychological dependence relative to drugs in IV Unit # 7 - Drugs, Alcohol, and Toxicology 6 Examples of Controlled Substances and Their Schedule Placement Schedule I—heroin (diacetylmorphine), LSD, marijuana, ecstasy (MDMA) Schedule II—cocaine, morphine, amphetamines (including methamphetamines), PCP, Ritalin Schedule III—intermediate acting barbiturates, anabolic steroids, ketamine Schedule IV—other stimulants and depressants including Valium, Xanan, Librium, phenobarbital, Darvon Schedule V—codeine found in low doses in cough medicines Unit # 7 - Drugs, Alcohol, and Toxicology 7 Identification of Drugs PDR—Physicians’ Desk Reference Field Tests—presumptive tests Laboratory Tests—conclusive tests Unit # 7 - Drugs, Alcohol, and Toxicology 8 Human Components Used for Drug Analysis Blood Liver tissue Urine Brain tissue Hair Kidney tissue Gastric Contents Spleen tissue Bile Vitreous Humor of the Eye Unit # 7 - Drugs, Alcohol, and Toxicology 9 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, whether it is a prescription, over the counter, or a controlled substance; as well as more detailed information about the drug. Unit # 7 - Drugs, Alcohol, and Toxicology 10 Drug Identification Confirmatory tests Screening or presumptive tests Spectrophotometry Ultraviolet (UV) Visible Spot or color tests Microcrystalline test— Infrared (IR) a reagent is added Mass spectrometry that produces a crystalline precipitate which is unique for a certain drug. Chromatography Unit # 7 - Drugs, Alcohol, and Toxicology 11 Presumptive Color Tests Marquis—turns purple in the presence of most opium derivatives and orange-brown with amphetamines Dillie-Koppanyi—turns violetblue in the presence of barbiturates Duquenois-Levine—turns a purple color in the presence of marijuana Van Urk—turns a blue-purple in the presence of LSD Scott test—color test for cocaine, blue Unit # 7 - Drugs, Alcohol, and Toxicology 12 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. Unit # 7 - Drugs, Alcohol, and Toxicology 13 Types of Chromatography Paper Thin Layer (TLC) Gas (GC) Pyrolysis Gas (PGC) Liquid (LC) High Pressure Liquid (HPLC) Column Unit # 7 - Drugs, Alcohol, and Toxicology 14 Paper Chromatography Stationary phase—paper Mobile phase—a liquid solvent Capillary action moves the mobile phase through the stationary phase Unit # 7 - Drugs, Alcohol, and Toxicology 15 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 Unit # 7 - Drugs, Alcohol, and Toxicology 16 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). Unit # 7 - Drugs, Alcohol, and Toxicology 17 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 Unit # 7 - Drugs, Alcohol, and Toxicology 18 Uses of Gas Chromatography Not considered a confirmation of a controlled substance Used as a separation tool for mass spectroscopy (MS) and infrared spectroscopy (IR) Used to quantitatively measure the concentration of a sample. (In a courtroom, there is no real requirement to know the concentration of a substance. It does not affect guilt or innocence). Unit # 7 - Drugs, Alcohol, and Toxicology 19 Spectroscopy Spectroscopy—the interaction of electromagnetic radiation with matter. Spectrophotometer—an instrument used to measure and record the absorption spectrum of a chemical substance. Unit # 7 - Drugs, Alcohol, and Toxicology 20 Spectrophotometry Components A radiation source A frequency selector A sample holder A detector to convert electromagnetic radiation into an electrical signal A recorder to produce a record of the signal Types Ultraviolet Visible Infrared Unit # 7 - Drugs, Alcohol, and Toxicology 21 Infrared Spectometry Material absorbs energy in the near-IR region of the electromagnetic spectrum. Compares the IR light beam before and after passing through a transparent sample. Result—an absorption or transmittance spectrum Gives a unique view of the substance; like a fingerprint Unit # 7 - Drugs, Alcohol, and Toxicology 22 Mass Spectrometry Gas chromatography has one major drawback, it does not give a specific identification. Mass spectrometry cannot separate mixtures. By combining the two (GCMS), constituents of mixtures can be specifically identified. Unit # 7 - Drugs, Alcohol, and Toxicology 23 Mass Spectrometry In a mass spectrometer, an electron beam is directed at sample molecules in a vacuum chamber. The electrons break apart the sample molecules into many positive charged fragments. These are sorted and collected according to their mass-to-charge ratio by an oscillating electric or a magnetic field. Unit # 7 - Drugs, Alcohol, and Toxicology 24 Mass Spectra Each molecular species has its own unique mass spectrum. Unit # 7 - Drugs, Alcohol, and Toxicology 25 IR Spectrophotometry and Mass Spectrometry Both work well in identifying pure substances. Mixtures are difficult to identify in both techniques Both are compared to a catalog of knowns Unit # 7 - Drugs, Alcohol, and Toxicology 26 People of Historical Significance Arthur Jeffrey Dempster was born in Canada, but studied and received his PhD from the University of Chicago. He began teaching physics there in 1916. In 1918, Dempster developed the first modern mass spectrometer. His version was over 100 times more accurate than previous ones developed, and established the basic theory and design of mass spectrometers that is still used to this day. Unit # 7 - Drugs, Alcohol, and Toxicology 27 People of Historical Significance Francis William Aston was a British physicist who won the 1922 Nobel Prize in Chemistry for his work in the invention of the mass spectrograph. He used a method of electromagnetic focusing to separate substances. This enabled him to identify no fewer than 212 of the 287 naturally occurring elemental isotopes. Unit # 7 - Drugs, Alcohol, and Toxicology 28 Unit #7 Drugs, Alcohol, and Toxicology “All substances are poisons. There is none which is not. The right dose differentiates a poison and remedy.” —Paracelsus (1495-1541). Swiss physician and chemist Unit # 7 - Drugs, Alcohol, and Toxicology 29 Toxicology and Alcohol Students will learn: • A quantitative approach to toxicology. • The danger of using alcohol. Unit # 7 - Drugs, Alcohol, and Toxicology 30 Toxicology and Alcohol Students will be able to: Discuss the connection of blood alcohol levels to the law, incapacity, and test results. Understand the vocabulary of poisons. Design and conduct scientific investigations. Use technology and mathematics to improve investigations and communications. Identify questions and concepts that guide scientific investigations. Communicate and defend a scientific argument. Unit # 7 - Drugs, Alcohol, and Toxicology 31 Toxicology Definition—the study of the adverse effects of chemicals or physical agents on living organisms. Types: – Environmental—air, water, soil – Consumer—foods, cosmetics, drugs – Medical, clinical, forensic Unit # 7 - Drugs, Alcohol, and Toxicology 32 Forensic Toxicology • Postmortem—medical examiner or coroner • Criminal—motor vehicle accidents (MVA) • Workplace—drug testing • Sports—human and animal • Environment—industrial, catastrophic, terrorism Unit # 7 - Drugs, Alcohol, and Toxicology 33 Toxicology Toxic substances may: – Be a cause of death – Contribute to death – Cause impairment – Explain behavior Unit # 7 - Drugs, Alcohol, and Toxicology 34 Historical Perspective of Poisoners • • • • Olympias—a famous Greek poisoner Locusta—personal poisoner of Emperor Nero Lucretia Borgia—father was Pope Alexander VI Madame Giulia Toffana—committed over 600 successful poisonings, including two Popes. • Hieronyma Spara—formed a society to teach women how to murder their husbands • Madame de Brinvilliers and Catherine Deshayes— French poisoners. AND many others through modern times. Unit # 7 - Drugs, Alcohol, and Toxicology 35 The Severity of the Problem “If all those buried in our cemeteries who were poisoned could raise their hands, we would probably be shocked by the numbers.” —John Harris Trestrail, “Criminal Poisoning” Unit # 7 - Drugs, Alcohol, and Toxicology 36 People of Historical Significance Mathieu Orfila—known as the father of forensic toxicology, published in 1814 “Traite des Poisons” which described the first systematic approach to the study of the chemistry and physiological nature of poisons. Unit # 7 - Drugs, Alcohol, and Toxicology 37 Aspects of Toxicity • • • • Dosage The chemical or physical form of the substance The mode of entry into the body Body weight and physiological conditions of the victim, including age and sex • The time period of exposure • The presence of other chemicals in the body or in the dose Unit # 7 - Drugs, Alcohol, and Toxicology 38 Lethal Dose • LD50—refers to the dose of a substance that kills half the test population, usually within four hours • Expressed in milligrams of substance per kilogram of body weight Unit # 7 - Drugs, Alcohol, and Toxicology 39 Toxicity Classes LD50 (rat,oral) Correlation to Ingestion by 150 lb Adult Human Toxicity <1mg/kg a taste to a drop extremely 1-50 mg/kg to a teaspoon highly 50-500 mg/kg to an ounce moderately 500-5000 mg/kg to a pint slightly 5-15 g/kg to a quart practically non-toxic Over 15g/kg more than 1 quart relatively harmless Unit # 7 - Drugs, Alcohol, and Toxicology 40 Federal Regulatory Agencies • • • • • Food and Drug Administration (FDA) Environmental Protection Agency (EPA) Consumer Product Safety Commission Department of Transportation (DOT) Occupational Safety and Health Administration (OSHA) Unit # 7 - Drugs, Alcohol, and Toxicology 41 Symptoms of Various Types of Poisoning Type of Poison Symptom/Evidence • Caustic Poison (lye) • Carbon Monoxide • • • • • • • Sulfuric acid Hydrochloric acid Nitric acid Phosphorous Cyanide Arsenic, Mercury Methyl (wood) or Isopropyl (rubbing) alcohol Characteristic burns around the lips and mouth of the victim Red or pink patches on the chest and thighs, unusually bright red lividity Black vomit Greenish-brown vomit Yellow vomit Coffee brown vomit. Onion or garlic odor Burnt almond odor Pronounced diarrhea Nausea and vomiting, unconsciousness, possibly blindness Unit # 7 - Drugs, Alcohol, and Toxicology 42 Critical Information on Poisons • • • • • • • • • • Form Common color Characteristic odor Solubility Taste Common sources Lethal dose Mechanism Possible methods of administration Time interval of onset of symptoms. • Symptoms resulting from an acute exposure • Symptoms resulting from chronic exposure • Disease states mimicked by poisoning • Notes relating to the victim • Specimens from victim • Analytical detection methods • Known toxic levels • Notes pertinent to analysis of poison • List of cases in which poison was used —John Trestrail from “Criminal Poisoning” Unit # 7 - Drugs, Alcohol, and Toxicology 43 To Prove a Case • • • • • • • Prove a crime was committed Motive Intent Access to poison Access to victim Death was caused by poison Death was homicidal Unit # 7 - Drugs, Alcohol, and Toxicology 44 Forensic Autopsy Look for: – Irritated tissues – Characteristic odors – Mees lines—single transverse white bands on nails. Order toxicological screens – Postmortem concentrations should be done at the scene for comparison – No realistic calculation of dose can be made from a single measurement Unit # 7 - Drugs, Alcohol, and Toxicology 45 Human Specimens for Analysis • Blood • Urine • Vitreous Humor of Eyes • Bile • Gastric contents • • • • Liver tissue Brain tissue Kidney tissue Hair/nails Unit # 7 - Drugs, Alcohol, and Toxicology 46 Alcohol—Ethyl Alcohol (C2H5OH) • Most abused drug in America • About 40% of all traffic deaths are alcohol-related • Toxic—affecting the central nervous system, especially • • • • • the brain Colorless liquid, generally diluted in water Acts as a depressant Alcohol appears in blood within minutes of consumption; 30-90 minutes for full absorption Detoxification—about 90% in the liver About 5% is excreted unchanged in breath, perspiration and urine Unit # 7 - Drugs, Alcohol, and Toxicology 47 Rate of Absorption Depends on: – amount of alcohol consumed – the alcohol content of the beverage – time taken to consume it – quantity and type of food present in the stomach – physiology of the consumer Unit # 7 - Drugs, Alcohol, and Toxicology 48 BAC Blood Alcohol Content • Expressed as percent weight per volume of blood • Legal limits in all states is 0.08% • Parameters influencing BAC: Body weight Alcoholic content Number of beverages consumed Time between consumption Unit # 7 - Drugs, Alcohol, and Toxicology 49 BAC • Burn off rate of 0.015% per hour but can vary: Male BAC male = 0.071 x (oz) x (% alcohol) body weight Female BAC female = 0.085 x (oz) x (% alcohol) body weight Unit # 7 - Drugs, Alcohol, and Toxicology 50 Henry’s Law • When a volatile chemical is dissolved in a liquid and is brought to equilibrium with air, there is a fixed ratio between the concentration of the volatile compound in the air and its concentration in the liquid; this ratio is constant for a given temperature. THEREFORE, the concentration of alcohol in breath is proportional to that in the blood. • This ratio of alcohol in the blood to alcohol in the alveolar air is approximately 2100 to 1. In other words 1 ml of blood will contain nearly the same amount of alcohol as 2100 ml of breath. Unit # 7 - Drugs, Alcohol, and Toxicology 51 Field Tests • Preliminary tests—used to determine the degree of suspect’s physical impairment and whether or not another test is justified. • Psychophysical tests—3 Basic Tests Horizontal gaze nystagmus (HGN): follow a pen or small flashlight, tracking left to right with one’s eyes. In general, wavering at 45 degrees indicates 0.10 BAC. Nine Step walk and turn (WAT): comprehend and execute two or more simple instructions at one time. One-leg stand (OLS): maintain balance, comprehend and execute two or more simple instructions at one time. Unit # 7 - Drugs, Alcohol, and Toxicology 52 The Breathalyzer • More practical in the field • Collects and measures alcohol content of alveolar breath • Breath sample mixes with 3 ml of 0.025 % K2Cr2O7 in sulfuric acid and water 2K2Cr2O7 + 3C 2H5OH + 8H 2SO4 2Cr2(SO4)3 + 2K2SO4 + 3CH3COOH + 11 H2O • Potassium dichromate is yellow, as concentration decreases its light absorption diminishes so the breathalyzer indirectly measures alcohol concentration by measuring light absorption of potassium dichromate before and after the reaction with alcohol Unit # 7 - Drugs, Alcohol, and Toxicology 53 Generalizations • During absorption, the concentration of alcohol in arterial blood will be higher than in venous blood. • Breath tests reflect alcohol concentration in the pulmonary artery. • The breathalyzer also can react with acetone (as found with diabetics), acetaldehyde, methanol, isopropyl alcohol, and paraldehyde, but these are toxic and their presence means the person is in serious medical condition. • Breathalyzers now use an infrared light absorption device with a digital read-out. Prints out a card for a permanent record. Unit # 7 - Drugs, Alcohol, and Toxicology 54 People in the News John Trestrail is a practicing toxicologist who has consulted on many criminal poisoning cases. He is the founder of the Center for the Study of Criminal Poisoning in Grand Rapids, Michigan which has established an international database to receive and analyze reports of homicidal poisonings from around the world. He is also the director of DeVos Children’s Hospital Regional Poison Center. In addition, he wrote the book, Criminal Poisoning, used as a reference by law enforcement, forensic scientists and lawyers. Unit # 7 - Drugs, Alcohol, and Toxicology 55