Transcript Forensic toxicology

FORENSIC TOXICOLOGY
Part I – Drugs of Abuse
Drug vs. Poison
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A drug is a natural or synthetic substance
designed to affect humans (or other animals)
psychologically and/or physically.
A drug taken in excess, showing its toxic
effects, causing illness or death is considered
a poison.
Dramamine Overdose:
Drowsiness, Seizures,
Convulsions, Difficulty
Breathing, DEATH
Controlled and Illicit Substances
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Controlled Substances are drugs or chemicals
whose manufacture, possession and use are
regulated by the government.
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Illegal Drugs (Drug Enforcement Agency)
Prescription Drugs (Federal Drug Administration)
Over the Counter Drugs (OTC)
Illicit Substances (aka drugs of abuse) are
drugs taken strictly for pleasure whether
produced legally or illegally.
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Designer Drugs – drugs produced solely for abuse and evasion
of specific drug laws.
Drug Classification According to
Pharmacology (4 Types)
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Pharmacology - The science of drugs, including their
composition, uses, and effects
1. Hallucinogens
(psychedellic drugs)
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Changes normal thought processes, perceptions and moods
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Desired Effects Include:
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Undesirable Side Effects
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Hallucinations (visual or auditory)
Super strength in some cases
Amnesia
Depression
Anxiety
Psychosis
Examples: Marijuana, LSD, PCP, Ecstasy (MDMA), Ketamine
Drug Classification (continued)
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2. Stimulants (Uppers)
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Act on the central nervous system to increase energy
and/or alertness while suppressing appetite and fatigue.
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Desired Effects Include:
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Undesirable Side Effects
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Mental alertness
Increased energy
Restlessness
Anxiety
Sudden Death
Examples: Caffeine, amphetamine, methamphetamines,
cocaine, nicotine
Drug Classification (continued)
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3. Narcotics (analgesics)
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Act on pain centers in the central nervous system
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Desired Effects Include:
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Pain relief
Anxiety relief
Undesirable Side Effects
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Synthetic narcotics are known as opiates
Death
Serum hepatitis
Examples: aspirin, Tylenol, Motrin, opium, heroin, codeine,
methadone, propoxyphene, oxycodon, fentanyl
Drug Classification (continued)
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4. Depressants (Downers)
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sometimes referred to as sedatives and tranquilizers, are
substances that can slow brain activity.
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Desired Effects Include:
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Undesirable Side Effects
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Anxiety relief
Relaxation
Depression
Chronic Fatigue
Anxiety
Examples: alcohol, barbiturates, quaaludes, valium
DEA Schedules of Controlled
Substances
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http://www.dea.gov/druginfo/ds.shtml
http://www.deadiversion.usdoj.gov/schedules/
Schedule I Controlled Substances
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Substances in this schedule have no currently
accepted medical use in the United States, a lack of
accepted safety for use under medical supervision,
and a high potential for abuse.
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Some examples of substances listed in Schedule I
are: heroin, LSD, marijuana, methaqualone, and
ecstasy.
DEA Schedules of Controlled
Substances
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Schedule II Controlled Substances
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Substances in this schedule have a high potential for
abuse which may lead to severe psychological or
physical dependence.
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Examples of Schedule II narcotics include: methadone,
oxycodone, Percocet, morphine, and opium.
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Example of Schedule II stimulants include:
methamphetamine
DEA Schedules of Controlled
Substances
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Schedule III Controlled Substances
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Substances in this schedule have a potential for
abuse less than substances in Schedules I or II and
abuse may lead to moderate or low physical
dependence or high psychological dependence.
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Examples of Schedule III narcotics include: Vicodin and
Codeine
Examples of Schedule III non-narcotics include: ketamine,
and anabolic steroids.
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DEA Schedules of Controlled
Substances
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Schedule IV Controlled Substances
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Substances in this schedule have a low potential for
abuse relative to substances in Schedule III.
Examples: Valium, Xanax, Halcion, Ambian
Schedule V Controlled Substances
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Substances in this schedule have a low potential for
abuse relative to substances listed in Schedule IV and
consist primarily of preparations containing limited
quantities of certain narcotics. Schedule V drugs are
generally used for antidiarrheal, antitussive, and
analgesic purposes
Example: some OTC cough medicines
Basic Laboratory Science
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Standard/reference samples allow the laboratory
to establish the known properties of a material so that
the identity of crime scene evidence can be determined.
Positive test – A test result that indicates the substance
being tested for is present in the sample.
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False positive test – A test result that indicates that the
substance being tested for is present when it is not.
Negative test – A test result that indicates that the
substance being tested for in a sample is absent or in
too small a quantity to be detected.
Basic Laboratory Science
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Qualitative test – A test that determines that a
substance is present.
Quantitative test – A test that determines how much
of a substance is present
Doe, Jane
ID# 1114
DOB 1/1/82
Normal range
Serum HCG
1520 mg/dL
O mg/dL
Screening tests vs.
Confirmatory Tests
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Screening test- a test that is nonspecific and
preliminary in nature.
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May test for a class of substances
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Example: Class: Opiates Drugs: heroin, morphine,
codeine
Often can be performed in the field – field test
Confirmatory test- a single test that specifically
identifies a substance
Principles of Drug Analysis
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Criminal penalties depend on the actual substance present in
a sample and the amount of substance present.
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Drug analysis process
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Step 1: Chemist performs screening tests
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Visual/microscopic
Microcrystalline
Spot test – In the field
Thin-layer chromatography (TLC) – in the lab
Step 2: Chemist performs a quantitative analysis to confirm the sample’s
identity and determine its mass
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Infrared spectroscopy (IR)
Gas Chromatography and mass spectroscopy (GC/Mass Spec)
The Spot Test
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Samples are mixed with chemicals to determine if
drugs are present
A positive test results in a color change.
Standards are always tested along with samples
Thin-layer Chromatography (TLC)
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A Separation technique that takes advantage of the
solubility and physical properties of the controlled
substance to separate and distinguish compounds in a
mixture
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Has solid stationary phase (silica gel plate) and liquid
moving phase (solvent).
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If the sample to be analyzed is solid, it must first be
dissolved in a suitable solvent.
Identifying Drugs by TLC
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Procedure:
A small amount of drug sample is applied to a TLC plate.
 Standards are always tested with samples.
 The plate is placed in a solvent.
 After a period of time, the plate is removed and visualized.
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Plates can either be placed under ultraviolet light revealing those
materials that fluoresce as bright spots on dark background.
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Or, the plate can be sprayed with a chemical reagent that reacts with
the separated substances and causes them to form colored spots.
Identifying Drugs by TLC
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Analysis of a TLC plate
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Rf is a calculated ratio of the distance moved by a drug relative to
the distance moved by the solvent used in developing the plate.
Drugs Crimes and Use Statistics
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Direct drug crimes consist of the possession,
manufacturing, and distribution of illicit
substances.
Indirect drug crimes are those that are
committed to support a person’s drug addiction
or are crimes that are committed while
someone is under the influence of drugs.
2012 Statistics for Illicit Drug Use in the US
12-17 yr.
9.5% 18-25 yr.
21.3% >25 yr.
7%