Transcript unit 2: forensic chemistry

UNIT 2: FORENSIC
CHEMISTRY:
INTRODUCTION:
Science is the careful observation of nature. By
making careful observations scientists can develop
guesses (called hypotheses) about why things occur
the way they do. Carrying out experiments further
tests these hypotheses..
If any of the experiments do not support the
hypothesis, it is discarded and a new one is
proposed, but if all the experimentation supports
the hypothesis, it is accepted by the scientific
community and called a theory. Science is therefore
testable, tentative, and explanatory.
Physical sciences
 include those sciences that study
nonliving systems. Of particular
importance to the field of forensic science
are chemistry, physics, and geology.
 The physical sciences unit is the largest
unit of the crime lab, and the largest part
of this unit is the chemistry
Chemistry
 is the science that studies matter and the changes it can
undergo.
 The reason for a large proportion of the crime lab
being devoted to chemistry is the need for the
analysis of drug evidence.
 The U.S. Constitution guarantees a defendant the
right to a speed} trial, and this requires a chemical
analysis of drug evidence before the case can go to
trial. The bulk of the physical evidence analyzed by
crime labs today is drug-related.
MATTER AND ATOMS:
 Matter is defined as anything that has
mass.
 Matter can be divided into pure
substances and mixtures.
 Pure substances: , like water and gold, have
a definite composition. Mixtures, such as
saltwater and coffee, have a composition
that can vary.
 Mixtures can further be classified as
homogeneous or heterogeneous. A
homogeneous mixture, such as a glass of
homogenized milk, has the same
composition throughout the mixture. A
heterogeneous mixture, such as oil mixed
with water, has a composition that varies
throughout the mixture.
 Pure substances can be further classified as
elements or compounds.
 Elements are the basic building blocks of
matter
 compounds are chemical combinations of
two or more different elements. Gold is an
example of an element, and water is an
example of a compound (water is a chemical
combination of the elements hydrogen and
oxygen).
 There are presently 115 different known
elements, but all the elements after uranium
(number 92) do not exist in nature.
Elements
 have one- or two-letter abbreviations called
chemical symbols. Hydrogen, for example, has the
symbol H, while helium has the symbol He.
 Two-letter symbols are needed since there are only
26 letters in the alphabet.
 When two letters are used to designate an element,
the first is always capitalized and the second is
always lowercase.
 Thus Co is the symbol for the element cobalt, while
CO stands for the compound carbon monoxide,
which is composed of the elements carbon and
oxygen.
ATOMS:
 The Greek philosopher Democritus (ca. 450
B.C.) believed that if an element was cut up
into smaller and smaller pieces, eventually
there would come a point where the matter
could no longer be divided.
 He called this ultimately tiny particle
atomos from the Greek meaning "cannot be
cut." From this, the present-day word atom
originates.
 All matter is composed of atoms. Elements
are the different types of atoms that exist.
 Atoms themselves are composed of three particles,
proton neutrons, and electrons.
 A proton has a relative charge of+1, and an
electron has a relative charge of-1 (a neutron has
no charge).
 Since all atoms charge of zero, the number of
protons must equal the number electrons.
 Neutrons and protons are located in a region at the
center of atom called the nucleus. Electrons orbit
the space surrounding the nucleus called the
electron cloud.
 The number of protons in the nucleus
defines what element an atom is.
 The atomic number is the number of
protons in the nucleus of an atom.
 The periodic table of the elements
arranges all the elements by atomic
number
ORGANIC CHEMISTRY
 There are many branches of chemistry, but
the three most important to forensic
science are organic, inorganic, and
analytical.
 Organic chemistry is the study of matter
that contains the element carbon.
 Inorganic chemistry is the study of matter
that does not contain the element carbon.
Of the compounds listed in the table below, the
first three are inorganic and the second three
are organic.
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Arsenic trioxide As203 Inorganic
Silver nitrate AgN03 Inorganic
Table salt NaCl Inorganic
Curare (curine) C18H19N3 Organic
Strychnine C21H22N202 Organic
Sarin C4H10F02P Organic
 From a forensic point of view it is important
to be able to distinguish between organic
and inorganic compounds.
 Organic samples often contain a complicated
mixture of compounds.
 Not only does this require extra steps in the
laboratory analysis, but organic compounds are
also more susceptible to degradation due to heat,
temperature, humidity, and microorganisms.
 Curare can break down hi body tissue in a matter
of days.
 Therefore, the investigator has much less time to
collect organic samples and submit them to the
crime lab.
 Once at the crime lab, organic samples are
normally kept in a walk-in refrigerator at 4°C
to ensure preservation.
 Organic chemicals offer the greatest
diversity of any type of compound.
 Of the more than 20 million known
compounds, about 95% are organic.
 Many poisons, such as, curare and
strychnine isolated from living systems
such as plants.
 Two of the most toxic compounds known
are tetrodotoxin (from the puffer fish) and
botulinum toxin (from the bacterium
Clostridium botulinum).
 The botulinum toxin is so lethal that 1 g
(about one-fifth of a teaspoon) could kill 1
million people.
ORGANIC COMPOUNDS:
 Forensic often analyze stomach
content during an autopsy by
weighing the contents of the stomach
for the presence of poisons.
 The type and amount of the drug can
be critical information for a forensics
investigator.
 As can the contents of the stomach.
Listed below are the 4 basic organic classes (
digested food can be tested for these classes to
confirm or deny suspect statements) .
 1. carbohydrates; used by the body as
source of energy. 3major groups:
 a. monosaccharide: simple sugar
containing 3-7 carbon atoms. Ex glucose,
fructose, galactose ( all with a C6H12O6
formula) Test reagent that is used for
identification for monosaccharides is
 Benedicts solution: Positive test is a green
color in the presence of a small amounts of
the simple sugar, orange with medium
amounts and finally brick red in the
presence of a large amount of the simple
sugar.
 b. disaccharide: Double sugar composed of
2 monosaccharides joined together
 Ex glucose + fructose---- sucrose,
 glucose + galactose ----lactose
glucose + glucose -----maltose
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 No TEST FOR DISSACHARIDE
2. Polysaccharide: starch—3 or more
monosaccharides joined together. Test reagent
is using Iodine and a positive test is a black-blue
color.
3. lipids; Includes fats and steroids, fat is used as
an energy source. Test is by using unglazed
paper and looking for a translucent spot upon
drying.
4. Proteins; Major molecule for the formation of
amino acids, enzymes, hormones, clotting
factors. And vitamins. Test is Biuret with a
positive test turning purple or violet in color
4. Nucleic Acids-Composed of carbon, hydrogen,
oxygen, nitrogen and phosphorus
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Two Types:
a. Deoxyribonucleic acid - DNA
1.) has 4 nitrogen bases - adenine, thymine, cytosine, guanine
2.) contains sugar deoxyribose
3.) contains phosphate group
4.) is double helix with shape Like twisted ladder.
Sides of ladder composed of sugar & phosphate with
nitrogen
bases making rungs of ladder.
b. Ribonucleic acid - RNA
1.) has 4 nitrogen bases - adenine, uracil, cytosine, guanine
2.) contains sugar ribose
3.) contains phosphate group
4.) is a single strand
ENZYMES – organic catalyst
that speed up reaction without
taking part in the reaction.
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Enzymes serve as catalyst by:
1. increasing frequency of
collisions
2. lowering activation energy
3. properly orienting colliding
molecules
Characteristics of
enzymes
1.
2.
3.
4.
5.
6.
7.
enzymes are proteins
have molecular weight of 10,000 to millions
enzymes are substrate specific (the substrate is
the molecule on which
the enzyme acts.)
enzymes are controlled by genes
enzymes are grouped according to the reaction
catalyzed
enzymes require co-enzymes
enzymes are affected by environmental factors,
temperature, pH, etc.
 Most enzymes contain a protein
part called an apoenzyme and a
non-protein part called a coenzyme.
 Co-enzymes are usually
vitamins or minerals.
Definitions
 Metabolism - the total of all
chemical reaction taking place in
the body.
 Anabolism -synthesis reactions in
the body.
 Catabolism - decomposition
reactions in the body. EX.
digestion
When food is broken down during
digestion, the base units must be
absorbed through the lining of the small
intestine:
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1. Amino acids pass directly into the
bloodstream
2. Monosaccharides pass directly into the
blood stream
3. Nucleotides pass directly into
bloodstream.
4. Fats-are broken into fatty acids and
glycerol. Since fats are not water soluble
they must be dissolved in micelles
(aggregates of bile salts) to be absorbed.
 The reactant in an enzyme reaction is
a substrate.
 Every enzyme is specific in its
actions and catalyzes only one
reaction or one type of reaction
 EX : Peroxidase is an enzyme found in the
liver. Peroxidase speeds up the breakdown
of hydrogen peroxide, a waste product of
cell metabolism that can be toxic in high
concentrations. The breakdown that occurs
is as follows:
 2H2O2 -*- 2H20 + 02
 Hydrogen Peroxide
Water
 Peroxidase, or catalase, is an enzyme found in
animals and plants, and in high concentration in
the cells of the liver. Peroxidase has an active site
that fits perfectly, like a lock and key, with
hydrogen peroxide.
 Other examples of enzymes would be lipase, which
only breaks down lipids; amylase, which only
breaks down amylose; and lactase, which only
breaks down lactose.
 When peroxidase, found in the liver, is
exposed to hydrogen peroxide, large
numbers of oxygen bubbles are
produced, as well as water; therefore,
a positive test for liver peroxidase will
produce large numbers of oxygen
bubbles when the liver is exposed to
hydrogen peroxide.
INORGANIC CHEMISTRY
 Inorganic compounds do not contain the
element carbon.
 Metal salts, and pure elements are
normally associated with inorganic
analysis.
 As opposed to organic compounds,
inorganic samples tend to be more
persistent.
 That is, they are more stable and
normally can be analyzed long after
exposure.
 Napoleon Bonaparte died in 1821 in exile on the
remote island of Saint Helena.
 Locks of his hair collected at the time of his death
and handed down through generations of families
as treasured heirlooms.
 Almost 140 years Napoleon's hair was analyzed
and found to contain traces of the metal arsenic.
 This has led to speculation that he was poisoned in
his last years.
 Thus inorganic compounds can be detected k after
organic compounds have broken down.
Napoleon Bonaparte
 Did forensic
evidence prove that
he was poisoned 140
yrs after his
death???
 Metals can be made up of pure samples of
an element, or thev can be mixtures known
as alloys.
 Even in the case of pure samples other
elements are present in trace amounts.
These trace elements often referred to as
"invisible markers" since they can be used
associate various fragments of metal with
a single source.
 Bullets are made of the element lead;
however, trace quantities of other
metals such as silver can also be
found in lead bullets.
 Antimony-also added in small
amounts to the lead to make the bullet
harder
In the case of the assassination
of President John F.
 Kennedy, the bullet fragments recovered from the
president, Governor John Connally, and the
presidential limousine were analyzed for the
invisibility markers silver and antimony.
 Since the amounts of silver and antimony vary
from bullet to bullet, this method could be used to
determine how many bullets were involved.
 In this case the silver antimony concentrations
were consistent with all the fragments coming from
two bullets, which supported the findings of the
Warren Commission.
 Did forensics
prove there was
not a second
gunman on the
grassy null??
Gunshot Residue
 Gunshot Residue (GSR) is expected to
be found on the shooters hands and
consists of Barium, Antimony and lead
Classes of Inorganic
Compounds:
 1. Water-Most important and
abundant inorganic compound
 a. Excellent solvent
 b. Participates in chemical reactions
 c. Absorbs and releases heat slowly
 d. Requires large amount of heat to
change from a liquid to a gas.
 e. Serves as a lubricant
 2. Acids-Compounds with one or more
hydrogen (H ) ions and one or more
anions(negative ions). , Their
characteristics include: sour taste, they
react with bases to form salts and water,
and they turn litmus paper red. EX
 a. H2PO4 - phosphoric acid
 b. HNO3 - nitric acid
 c. H2SO4 - sulfuric acid
 d. H2CO3 - carbonic acid
 3. Bases-Compounds with one or more
cations (positive ions) and one or more
hydroxyl ions (OH). They are characterized
by having a bitter taste, being corrosive and
turning litmus paper blue
 a. KOH - potassium hydroxide
 Read acid bath story pg 47 forensic CSI
book
ANALYTICAL vs
QUALITATIVE CHEMISTRY:
 Analytical chemistry is the branch of
chemistry involved in qualitatative and
quantitative analysis.
 Qualitative analysis involves the
identification of a compound.
Quantitative analysis
 Quantitative analysis involves the
determination of the amount of a substance
present. The identity of a compound]
sometimes used to establish whether a law
has been broken white powder sent to the
crime lab may contain cocaine, or it may
contain pancake flour. It is up to the crime
lab to determine the identity of the unknown
chemical. The quantity also determines the
crime.
Gas Chromatography:
 The identification of chemicals is normally carried out by
spectroscopy, which is the study of spectra (plural of
spectrum).
 A spectrum is the orderly arrangement of a more
complex phenomenon such as light, sound, or mass.
White light is the combination of all the colors in the
spectrum. It can be separated into its component colors
by passing it through a prisms
 For forensic science, light and mass are the most
important spectra because they can be used to identify
chemicals.
 These spectra act as fingerprints and can be used in a
court to prove the true identity of a material.
Gas Chromatography:
 The problem with
spectroscopy is that
the sample must be a
pure compound or else
a positive identification
cannot be made.
spectra from a mixture
of compounds is
useless to a forensic
investigator.
Gas Chromatography:
 The problem of separating
complicated mixtures of organic com1 pounds was simplified by the
discovery of chromatography in 1903
by Mikhail Tswett.
 Tswett used a glass column filled with
calcium carbonate (chalk) to separate
the pigments in a leaf.
Tswett called this process
chromatography, which
means color writing.
 Liquid chromatography (LC) is more
difficult to set up but has advantage of
operating at room temperature. Its use
is normally restricted to compounds
that decompose at the temperatures
required for gas chromatography.
Spectroscopy:
 For organic compounds the two most
commonly used forms of identification
are mass spectroscopy (MS) and
infrared (IR) spectroscopy.
 Mass spectroscopy is the preferred
method of analysis for organic
samples
 A mass spectrometer smashes a
compound into fragments and
produces a mass spectrum of the
compound and its fragments.
 This spectrum is unique for each
compound and can be used to identify
a chemical in court.
 An infrared spectrometer works by
measuring the infrared light absorbed
by a sample.
 Infrared light is lower in energy than
visible light and allows infrared
spectra to be used as fingerprints to
identify chemical, but is very time
consuming.
Summary of Techniques
 The method of choice for the analysis
of organic compounds is a gas
chromatograph-mass spectrometer
(GC/MS).
 The preferred method of analyzing
inorganic samples or elements is
atomic spectroscopy, which includes
atomic absorption and atomic
emission spectroscopy.
TOXICOLOGY:
 The word
toxicology comes
from the Greek
term toxon, which
means "bow."
 The tips of bows
were sometimes
dipped in poison to
make them more
deadly.
Forensic Toxicology
 Postmortem—medical examiner or coroner
 Criminal—motor vehicle accidents (MVA)
 Workplace—drug testing
 Sports—human and animal
 Environment—industrial, catastrophic,
terrorism
Chapter 8
Toxicology
Toxic substances may:
 Be a cause of death
 Contribute to death
 Cause impairment
 Explain behavior
Chapter 8
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”
Chapter 8
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.
Chapter 8
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
Chapter 8
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
Chapter 8
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
Chapter 8
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)
Chapter 8
Symptoms of Various Types
of Poisoning
Type of Poison
 Caustic Poison (lye)
 Carbon Monoxide
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Sulfuric acid
Hydrochloric acid
Nitric acid
Phosphorous
Cyanide
Arsenic, Mercury
Methyl (wood) or
Isopropyl (rubbing) alcohol
Chapter 8
Symptom/Evidence
Characteristic burns around the lips and
mouth of the victim
Red or pink patches on the chest and thighs,
unusually bright red lividity remain in body . .
Up to 6wks
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
 There is a suggestion that this mental affliction was
attributable to mercury poisoning from his chemical
experiments.
 Indeed, Newton was known to experiment widely in
his laboratory with mercury.
 Mercury poisoning is associated with ‘. . . morbid
irritability, insomnia, and mental hyperactivity’, all the
features that Newton displayed throughout his life.
 Modern studies of Newton’s hair at Cambridge
University showed high levels of mercury.
Chapter 8
Beethoven
 Even if Beethoven was deaf, he 'listened' to his doctor.
 But this proved even worse, as his doctor poisoned him. With
lead. A Viennese forensic expert shows that the composer's
physician unwittingly overdosed the genius with the toxic
metal.
 It was clear that the master had been very ill years before his
death in 1827, at the age of 57.
 Previous analyses showed that Beethoven had experienced lead
poisoning, with high levels of the toxin in his hair and bones.
Chapter 8
Erratic behaviour
 A new study suggests that
Lincoln's erratic behaviour may
have been linked to the pills he
took to treat his persistent
"melancholia".
 The pills, known as blue mass,
contained the metal mercury in
potentially toxic doses that
exceeded modern day safety
limits by nearly 9,000 times.
 The researchers believe that this
toxic effect may have had a
profound impact on Lincoln's
Chapter 8
mood.
 The former US president
was famous for his patience.
 But earlier in life he was
also prone to outbursts of
uncontrollable rage.
 Carbon dioxide remains in the blood for up to 6
months after a person dies.
 Hydrogen sulfide smells like rotten eggs at low
levels but at higher concentration, cannot be
detected by smell and is quite lethal.
 Arsine is the hydride of arsenic and forms a
colorless gas with an odor of garlic.
 Chlorine gas can also be very poisonous, but it is
usually formed by accident when household
chemicals such as bleach (sodium hypochlorite)
and toilet bowl cleaner (hydrochloric acid) are
mixed
 Hydrogen cyanide is formed when an acid reacts
with a salt of cyanide. The resulting gas is very
poisonous and smells of bitter almonds.
 Some pathologists can detect cyanide poisoning
from the odor during the autopsy.
 About 50 mg of cyanide is considered a lethal
dose.
 Cyanide works by inactivating the enzyme
cytochrome oxidase and blocking the oxidation of
glucose inside cells. The person dies in a matter of
minutes.
Critical Information
on Poisons
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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”
Chapter 8
To Prove a Case
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Prove a crime was committed
Motive
Intent
Access to poison
Access to victim
Death was caused by poison
Death was homicidal
Chapter 8
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
Chapter 8
Human Specimens for Analysis
 Blood
 Urine
 Vitreous Humor of Eyes
 Bile
 Gastric contents
Chapter 8
 Liver tissue
 Brain tissue
 Kidney tissue
 Hair/nails
TOXICOLOGY:
 This is also where the tradition of toasting and
touching wine goblets together to prove not
deadlysubstance was present.
 Toxicology is the study of body fluids, tissue,
and organs for the presence of drugs or
poisons. A toxicologist must have a minimum of
a baccalaureate degree, a master's degree, or a
Ph.D. in the physical or biological sciences. At
least 2 years of work in toxicology is normally
required after graduation
 The time required to detect drugs using
blood urine, saliva, or sweat varies from
about 1 to 5 days.
 In the case of hair testing it takes about 5
days for a drug or its metabolites to appear
in the hair, but its presence can be detected
for 6 months or more.
 Many types of poisons can be present in a
victim.
There are many organic poisons, both
naturally occurring (produced in nature)
and synthetic (made in a laboratory).
 Organic poisons include alkaloids, barbiturates,
glycosides, ricin, botulin, curare, and various
venoms. Alkaloids are mtrogen-contammg
coYcipoxx-n&s extracted from plants.
 Curare, an extract from the bark of the tree
Strychnos toxifera, is an example of an alkaloid.
 Certain South American tribes prepared the poison
by boiling the bark and a mixture of other
ingredients for about 2 days. The solution was then
strained and used in darts for blowguns to bring
down birds or mammals.
 Curare causes the paralysis of skeletal muscles,
which can lead to death by suffocation. The
person is awake and aware of the paralysis until
unconsciousness sets in.
 Strychnine is another related alkaloid that can be
extracted from the tree Strychnos nux-vomica.
 Strychnine is a convulsive and causes the victim
to suffer convulsions of all their voluntary
muscles before death by asphyxia sets in.
 . Botulinal toxin, produced by the bacterium
Clostridium botulinum, is the most toxic poison
known. As little as 1 g of this toxin could kill 1
million people.
Inorganic and metallic
poisons
 include antimony, arsenic, barium, lead,
mercury, phosphorus, and thallium.
 Poisoning by the heavy metals mercury
and lead occurs when these metals react
with enzymes in the body and inactivate
them.
 Symptoms of heavy metal poisoning often
include stomach pains, coma, and then
death
 Lead poisoning: brain damage, found in
paint, x-ray shielding old water pipes, lead
gas
factors that influence effects
of poisoning in the body:
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1. dose
2. form of entry
3. duration of exposure
4. weight
 LD50: kills at least 50% test population
exposed to substance
Drugs
“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
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.
Chapter 7
ILLEGAL DRUGS
 Illegal drugs and related materials are the
largest class of physical evidence received by
crime labs.
 The abuse of drugs can result in tolerance and
dependency.
 The federal government keeps track of illegal
drugs that are showing up in arrests on the
street.
 The most used illegal drugs are listed in a
threat matrix published by the National Drug
Intelligence Center of the U.S. Department of
Justice
 Nationally 37% of state and local police
agencies identify cocaine as the major drug
threat. Next are methamphetamine at 36%,
marijuana at 13%, heroin at 9%
 State and local police agencies estimate
that cocaine abuse contributes the most of
violent crime, about 50% and to property
crime about 42%
 The leaves of the coca plant are used to
extract cocaine.
Sigmund Freud
 Sigmund Freud
considered cocaine
a wonder drug an
prescribed it to his
patients.
 1886 Coca Cola
Company marketed its
new soft drink, made
from the same coca
leaves ( it contained 60
mg of cocaine.
 In 1903 the company
was forced to remove
cocaine from its
beverage, but it uses
the leaves ( cocainefree) for flavor to this
day.
 Cocaine mixed with an aqueous solution of
baking soda and heated is called crack
 Methamphetamine in the powdered form is
called crystal or crank, ice methamphetamine
looks like tiny pieces of ice.
 Marijuana is the most commonly used illegal
drug in the United States.
 Heroin is a narcotic ( meaning it reduces pain
and causes sleep) and
 Morphine is the active ingredient of opium, the
juice of the unripe poppy plant
Wizard of Oz
 There is a famous
scene in the Wizard
of Oz where the
witch says, Poppies
will make them
sleep referring to
opium.
Bayer
 In 1898 Bayer marketed a
new wonder drug
designed to cure all sorts
of ailments.
 This wonder drug could
be purchased at the local
drug store by the name of
Bayer Heroin.
 After heroin became illegal
the Bayer switched to its
next miracle drug, aspirin.
 Ecstasy is a hallucinogen that is synthetic and is in a
group of club drugs.
 Pharmaceuticals are the class of abused substances that
are available legally by prescription. Ex valium, Ritalin
ect…
 Club drugs include GHB and Rohpnol which are tasteless
and odorless, and can be slipped into a persons drink
without their knowledge. Rohypnol can cause amnesia so
the person may not remember the events that occurred
when they were incapacitated.
 The first synthesized LSD was in 1943 from ergot fungus
 PCP can cause a feeling of invincibility to the user and
many individuals find they have broken bones or torn
tendons , muscles and ligaments while on PCP
CONTROL SUBSTANCE
ACT;
 1970 Controlled substance act placed
drugs in schedules and these drugs
are called controlled substances and
cannot be obtained legally without a
prescription
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
Chapter 7
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
Chapter 7
Human Components
Used for Drug Analysis
Chapter 7
® Blood
® Liver tissue
® Urine
® Brain tissue
® Hair
® Kidney tissue
® Gastric Contents
® Spleen tissue
® Bile
® Vitreous Humor of
the Eye
ANALYSIS OF DRUG
EVIDENCE:
 The collection of drug evidence must be done with care.
Many drugs are so potent that they can cause an effect
through inhalation or absorption through the skin. Drug
analysis is done in two steps:
 1. Presumptory test: first quick and easy screening to
determine if a drug is probably present ( color test for
drugs)
 2. Confirmatory test: to positively prove the presence o f
a drug
Drug Identification
Screening or
presumptive tests
® Spot or color tests
® Microcrystalline test—
a reagent is added that
produces a crystalline
precipitate which is
unique for a certain
drug.
® Chromatography
Chapter 7
Confirmatory tests
® Spectrophotometry
® Ultraviolet (UV)
® Visible
® Infrared (IR)
® Mass spectrometry
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
Chapter 7
 Presumptory test can yield false positive
test, for this reason they cannot be used in
court to positively prove the presence of a
drug.
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.
Chapter 7
Types of Chromatography
®Paper
®Thin Layer (TLC)
®Gas (GC)
®Pyrolysis Gas (PGC)
®Liquid (LC)
®High Pressure Liquid (HPLC)
®Column
Chapter 7
Paper Chromatography
® Stationary phase—paper
® Mobile phase—a liquid
solvent
Capillary action moves
the mobile phase
through the stationary
phase
Chapter 7
ALCOHOL:
 Considered a stimulant
 The limit for DWI has been set at the
federal level at 0.08%
 The rate of absorption of alcohol by the
human body is controlled by 4 factors:
 The quantity of alcohol consumption
 The time over which the alcohol was
consumed
 form of the alcohol
 contents of the stomach
 The body eliminates alcohol by excretion
and oxidation. ( about 5% alcohol leaves
body unchanged in breath, sweat and urine)
 Excretion occurs by breathing, sweating,
and urination, and oxidation occurs in the
liver.
 The rate of elimination is constant and can
be calculated by the formula
Rate of elimination = 0.01 + 0.014(weight/300lb
 One drink is defined as:
 10 oz to 12 oz beer at 4to 5% alcohol
 8 to 12 oz wine cooler at 4 to 6 %
alcohol
 4 to 5 oz table wine 9 to 12 % alcohol
 1.25 oz of 80 proof alcohol
 1 oz 100 proof alcohol
)
 In the case of wine and beer: which don’t
use proof the formula for rate of
eleimation is:
 Ma = .23 x ounces of liquor x proof
 When alcohol enter the body, it dissolves in all body fluids,
thus blood alcohol content (BAC) can be calculated with the
following formula
 %BAC(g/100mL) = 0.10 x MA/(VD x MB)
 MA = mass of alcohol ( # grams of alcohol)
= .11 x oz liquor x proof
 MB = body mass ( kg) = body weight/2.2
 VD = volume of distribution (L/Kg) is 0.7 for
men and .6 for women
 EXAMPLE: A 120 lo woman consumes 3 drinks
each containing one shot of 80 proof vodka. What
is her BAC? ( each mixed drink is assumed to
contain 1 jigger of 1.5 oz vodka)
 Three drinks = 3 x 1.5 oz = 4.5 oz
 MA = .011 x oz of liquor x proof

= .011 x 4.5 oz x 80

= 39.6 g
 VD = .6 L/kg ( woman)
 MB= 120 lb/2.2lb/kg = 55 kg
 %BAC(g/100mL) = 0.10 x MA/(VD x MB)

= .10 x 39.6g/(.6L/kg x 55 kg)

= 0.12%
BREATHALYZER:
 The alcohol in a person’s blood is about
2100 times more concentrated than the
alcohol in a person’s breath. This ratio is
controlled by body temperature, so it is the
same for each person.
 A breathalyzer measures the alcohol
content of a person’s breath, multiplied it
by 2100 and calculates the BAC