Drugs

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You will understand:

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.

Objectives

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You 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.

Objectives, continued

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You will be able to:

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.

Objectives, continued

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Drugs and CrimeA drug is a natural or synthetic substance designed to affect the subject

psychologically or physiologically.

A poison is a drug that shows toxic effects.

“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.

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Why do we care?

The Office of National Drug Control Policy estimates that illegal drug use costs society $110 billion a year. Drug-related violence and crime also pose a grave and much more direct threat to the United States. According to the 1999 Arrestee Drug Abuse Monitoring Program, 75% of the male adults arrested in NYC for committing a violent crime tested positive for drug use. The report also showed that even in smaller cities, these figures ranged as high as 65%.

The drug epidemic is also taking a toll on the very core of American society -- the family. Drug use causes violence and abuse within families: One-quarter to one-half of all incidents of domestic violence are drug related. A survey of state child-welfare agencies found substance abuse to be one of the key problems exhibited by 81% of the families reported for child neglect and abuse. Additionally, 3.2% of pregnant women -- nearly 80,000 mothers -- use drugs regularly, which will affect their babies.

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Controlled Substances ActSchedule I—high potential for abuse; no currently

accepted medical use in the U.S.; a lack of accepted safety for use under medical supervision

Examples: heroin (diacetylmorphine), LSD, marijuana, ecstasy (MDMA)

Schedule II—high potential for abuse; a currently accepted medical use with severe restrictions; abuse may lead to severe psychological or physical dependence

Examples: cocaine, morphine, amphetamines (including methamphetamines), PCP, Ritalin

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Controlled Substances Act, continued

Schedule III—lower potential for abuse than the drugs in I or II; a currently accepted medical use in the U.S.; abuse may lead to moderate physical dependence or high psychological dependence

Examples: intermediate-acting barbiturates, anabolic steroids, ketamine

Schedule IV—low potential for abuse relative to drugs in III; a currently accepted medical use in the U.S.; abuse may lead to limited physical or psychological dependence relative to drugs in IIIExamples: stimulants and depressants including Valium, Xanax, Librium, phenobarbital, Darvon

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Controlled Substances Act, continuedSchedule V—low potential for abuse relative to drugs in IV; currently

accepted medical use in the U.S.; abuse may lead to limited physical or psychological dependence relative to drugs in IV

Examples: codeine found in low doses in cough medicines

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Illegal or Illicit?An illegal drug is a drug that is against the law to have, use, or distribute.

An illicit drug is a legal drug used in an inappropriate or illegal way.

Cocaine Crack

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Classification of Illicit Drugs Hallucinogens—induces changes in normal thought processes, perceptions, and moods (marijuana, LSD, PCP, MDMA/ecstasy, Ketamine)

Stimulants—speeds up the CNS (speed, cocaine, club drugs, anabolic steroids); includes caffeine and nicotine

Narcotics—a drug that induces sleep and depresses vital body functions such as blood pressure, pulse rate, and breathing rate (morphine, heroin, methadone, codeine); analgesics, affect CNS to relieve pain (aspirin, acetaminophen, ibuprofen)

Depressants—slows the CNS (alcohol, barbiturates, Valium), often prescribed to reduce anxiety or as a sleep aid; huffing propellants and solvents

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Identification of Drugs

PDR—Physicians’ Desk Reference

Field Tests—presumptive tests

Laboratory Tests—conclusive tests

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Physicians’ Desk ReferencePDR—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.

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Human Components Used for Drug AnalysisBlood

Urine

Hair

Gastric contents

Bile

Liver tissue

Brain tissue

Kidney tissue

Spleen tissue

Vitreous humor of the eye

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Forensic Drug Analysis and Identification

Forensic Chemist must have a plan of action

1. Screening or presumptive tests (used to reduce the number of

possible identities of an unknown substance) Spot or color tests Microcrystalline test—

a reagent is added that produces a crystalline precipitate which is unique for a certain drug.

Chromatography

2. Confirmatory tests (test that specifically identifies a substance)

Spectrophotometry Ultraviolet (UV) Visible Infrared (IR)

Mass spectrometry

Qualitative determine what is in a mixture

Quantitative determine the % combination of components in the mixture

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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.)

Drug Identification, continued

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Presumptive Color TestsMarquis—turns purple in the presence of

most opium derivatives and orange-brown with amphetamines

Dille-Koppanyi—turns violet-blue 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

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Presumptive Color TestsDrug Reagent Color Marijuana Duquenois-Levine (D-L) Blue-violet LSD Erlich/Van Urk (ERL) Blue-violet Amphetamines Marquis (MARQ) Red-orange brown Cocaine Cobalt thiocyanate (CO) Blue flaky precipitate Heroin Marquis (MARQ) Purple Barbiturates Dille-Kopanyi (D-K) Violet

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ChromatographyA 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

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Types of ChromatographyPaper

Thin-layer (TLC)

Gas (GC)

Pyrolysis gas (PGC)

Liquid (LC)

High-performance liquid (HPLC)

Column

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Paper ChromatographyStationary phase—paper

Mobile phase—a liquid solvent

Capillary action moves the mobile

phase through the stationary phase.

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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).

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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

Watch animated depictions of Thin-Layer Chromatography and Gas Chromatography at www.prenhall.com/hsforensics

Click on Chapter 5 Drugs, and go to Web Extras

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Gas ChromatographyPhases

Stationary—a solid or a viscous liquid that lines a tube or column

Mobile—an inert gas like nitrogen or helium

AnalysisShows a peak that is proportional to the quantity of the substance present

Uses retention time instead of Rf

for the qualitative analysis

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Uses of Gas ChromatographyNot 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.)

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Confirmatory Tests: SpectroscopySpectroscopy—the interaction of electromagnetic radiation with

matter

Spectrophotometer—an instrument used to measure and record the absorption spectrum of a chemical substance

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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

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Infrared Spectrometry

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 See how a spectrophotometer works www.prenhall.com/hsforensics

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Mass SpectrometryGas 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.

Watch the GC/MS at work www.prenhall.com/hsforensics

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Mass Spectrometry, continuedIn 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 magnetic field.

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Mass Spectra

Each molecular species has its own unique mass spectrum.

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IR Spectrophotometry and Mass SpectrometryBoth work well in identifying pure substances.

Mixtures are difficult to identify in both techniques.

Both are compared to a catalog of knowns.

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People of Historical SignificanceArthur Jeffrey Dempster was born in Canada, but studied at 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 and established the basic theory and design of mass spectrometers that is still used to this day.

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People of Historical Significance, continuedFrancis 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.

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Forensic toxicology helps determine (a) the cause-and-effect relationships between exposure to a drug or other substance and (b) the toxic or lethal effects from that exposure.

People can be exposed to toxic substances: ® intentionally—by treating illness or

relieving pain ® accidentally—by harmful

combinations or overdoses ® deliberately—by harming or killing

others or by committing suicide

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Poison—Murder, Accidental Overdoses, and Drug Offenses

® Less than ½ of 1% of all homicides results from poisoning.

® Accidental drug overdoses are more common.

® More than 50% of the federal prison population and about 20% of the population in state prisons consist of drug offenders.

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Controlled SubstancesHallucinogens

® The effect and intensity of response to these drugs varies from person to person.

® Often derived from plants, hallucinogens affect the user’s perceptions, thinking, self-awareness, and emotions.

® Affects of an overdose include an increased heart rate, often increased blood pressure, and sometimes panic attacks, anxiety, or psychosis.

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Controlled SubstancesNarcotics

Narcotics reduce pain and can be very habit forming.

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Controlled SubstancesStimulants

® Stimulants increase feelings of energy and alertness while suppressing appetite.

® As the drug wears off, however, depression often results.

® Affects of an overdose can include high blood pressure, agitation, confusion, or seizures.

® Stimulants tend to be highly addictive.

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Controlled SubstancesAnabolic Steroids

® These drugs are produced in a laboratory and have a chemical structure similar to testosterone.

® Anabolic steroids promote cell and tissue growth increasing bone mass and body muscle.

® Because of this they are popular with weightlifters, bodybuilders, and other athletes.

® What are some of the negative side effects that are possible?

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Controlled SubstancesDepressants

® Depressants act on the central nervous system and increase the activity of a neurotransmitter called GABA.

® Increased GABA production results in drowsiness and slowed brain activity.

® These drugs, consequently, relieve anxiety and produce sleep.

® Mixing depressants with alcohol and other drugs increases their effects and health risks, possibly leading to coma and death.

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Controlled SubstancesAlcohols

® In what way are alcohols toxic?

® How is grain alcohol produced?

® What are the classic symptoms of a hangover?

® What is the effect of alcohol on the central nervous system?

® What can chronic abuse of alcohol cause?

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Controlled SubstancesBacterial Toxins

Tetanus ® Lockjaw, as it is sometimes called, is produced by the

Clostridium tetani bacteria. ® Its poison can cause violent muscle spasms.

Botulism ® Produced by the bacteria Clostridium botulinum,

botulism paralyzes muscles. ® It causes irreversible damage to nerve endings. ® Very small amounts are extremely deadly. ® Botulism is the most poisonous biological substance.

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Controlled SubstancesPesticides and Heavy Metals

Pesticides mostly are used to protect plants or food crops. Metal compounds are very poisonous.

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Controlled SubstancesPesticides and Heavy Metals Metal compounds can damage many organs in the body.

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Controlled SubstancesBioterrorism Agents

Ricin ® is a poisonous protein in the castor bean. ® is lethal in extremely small amounts. ® can enter the body in various ways:

® inhaled as a mist or a powder. ® ingested as food or drink. ® injected into the body.

® can cause death within a few hours.

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Controlled SubstancesBioterrorism Agents

Anthrax ® is caused by the bacteria Bacillus anthracis, which forms

spores. ® can be spread to humans from infected animals. ® can enter the human body through:

® inhalation; causing breathing problems that usually result in death.

® ingestion; becoming fatal in 25% to 60% of cases. ® absorption via the skin; leading to death in about 20%

of untreated cases.

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. . . . . . . . . . . . . . . . . Summary. . . . . . . . . . . . . . . . . Summary

® Forensic toxicology seeks to identify poisons or drugs in criminals and victims.

® Toxicology is important in studying cases of drug overdose and sporting violations.

® Controlled substances fall into five main groups. ® Poisons can be produced by living organisms. ® Pesticides and heavy metals are common poisons. ® Bioterrorism agents include ricin and anthrax.