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DRUGS

Chapter 5

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Introduction• Drug - a natural or synthetic substance that

produces physiological or psychological effects in humans or other animals.

• 75% of all evidence being processed in crime labs is related to illegal drugs

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DEA – NJ Drug StatisticsNJ State Facts (http://www.justice.gov/dea/pubs/state_factsheets/newjersey.html)

• Population: 8,717,925• State Prison Population: 26,757• Probation Population: 143,315 • Violent Crime Rate National Ranking: 26

2010 Federal Drug Seizures• Cocaine: 900.78 kg• Heroin: 140.21 kg• Methamphetamine: 47.94 kg/26 DU• Marijuana: 2,887.80kg• Hashish: 57.55 kg.• MDMA: 3,790 DU• Meth Lab Incidents: 3 (DEA, state, and local)

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Narcotics• Narcotics - drugs that

induce sleep and relieve pain

Lowers blood pressure and slows breathing rate

Examples:- Heroin- Morphine - Codeine

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Hallucinogens• Hallucinogens include marijuana, LSD,

PCP, and MDMA (Ecstasy)• PCP is often mixed with other drugs, such as

LSD, or amphetamine, and is sold as a powder (“angel dust”), capsule, or tablet.

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Depressants• Depressants - are substances

used to slow down the functions of the central nervous system.

• Depressants calm irritability and anxiety and may induce sleep.

• Examples: - alcohol - Xanax

-Rohypnol - Barbiturates

“Roofies”-tranquilizers

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Stimulants• Stimulants – substance that speeds up, or

stimulates, the central nervous system• Stimulants give the user an adrenaline rush often

followed by a crash. • Heavy use of stimulants result in paranoia,

restlessness, irritability, and depression.

• The most frequently used stimulant is coffee with caffeine.

• The most common illegal stimulants are cocaine and amphetamines.

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Amphetamines• A group of synthetic stimulants that

are usually called UPPERS or SPEED.

• Used in diet pills• Hydroxycut with Ephedra

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COCAINE• Erythroxoylon coca – the plant• Increases alertness and energy• Suppression of hunger, fatigue, and

boredom

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Drug-Control Laws• The U.S. federal law known as the Controlled

Substances Act will serve to illustrate a legal drug-classification system created to prevent and control drug abuse.

• This federal law establishes five schedules of classification for controlled dangerous substances based on the drug’s– potential for abuse– potential for physical and psychological dependence– medical use/value

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Your Brain on Drugs• Youtube - https://www.youtube.com/

watch?v=N6NL41bREHo

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• A forensic chemist will determine if a unknown substance is a drug by performing a series of tests

• The results will have a direct bearing on the process of determining the guilt or innocence of a defendant.

Forensic Drug Analysis

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Drug Identification

2-step procedure:

1) Use screening tests to reduce the number of possibilities to a small and manageable number.

2) Use more sophisticated tests to pinpoint and confirm the identity of the drug.

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Drug Identification

Screening tests

• Color tests

• Microcrystalline test

• Chromatography

Confirmatory tests

• Spectrophotometry

Ultraviolet (UV) Visible Infrared (IR)

• Mass spectrometry

Screening tests only tells what drug is possibly present. (Screening tests are easier, cheaper, and quicker to use.)

Confirmatory tests tell that the drug is definitely present.

Video – Drug Analysis

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Screening tests• Color Tests (5 tests) - Suspect material is

subjected to a series of different color tests that will produce characteristic colors for the more common illicit drugs.

• Microcrystalline Test

Forensic Drug Analysis

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5 Color Tests1. Marquis

– turns purple when positive for heroin and morphine

– turns orange-brown when positive for amphetamines and methamphetamines.

2. Dille-Koppanyi – tests for barbiturates

3. Duqenois-Levine – series of chemicals to test for marijuana

4. Van Urk –tests for LSD

5. Scott – three solution test for the presence of cocaine. Positive color sequence is blue-pink-blue.

Video - https://www.youtube.com/watch?v=ue9zp5P2Mxo

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Microcrystalline Tests

• Microcrystalline tests - used to identify specific drug substances by studying the size and shape of crystals formed

Cocaine crystal – “K” shaped methamphetamine crystal

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Confirmation Determination• Forensic chemists will employ a specific test to

identify a drug substance to the exclusion of all other known chemical substances.

• Typically infrared spectrophotometry or gas chromatography-mass spectrometry (GCMS) is used to specifically identify a drug substance.

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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.

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Types of Chromatography

Paper Thin Layer (TLC) Gas (GC) Pyrolysis Gas (PGC) Liquid (LC) High Pressure Liquid (HPLC) Column

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Paper Chromatography

Stationary phase—paper Mobile phase—a liquid solvent

Capillary action moves the mobile phase through the stationary phase

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Calculating Rf Values• The distance moved by a pigment is

compared to the distance moved by the solvent front. We call this relationship the retention time or Rf value and define it as follows:

 Rf = Distance moved by the pigment

Distance from pigment origin to solvent front

 • Paper chromatography can be used to

identify substances both qualitatively (by color) and quantitatively by its characteristic Rf value.

 

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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

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Gas ChromatographyIn GC, the moving phase is actually a gas called the carrier gas, which flows through a column.

Phases Stationary —liquid that lines a

tube or column Mobile — a gas like nitrogen or

helium

• After a mixture passes through the length of the column, it will become separated into its components.

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Gas Chromatography Results• Chromatogram: The printed record of the separation. • Retention Time: The time required for a component to

come out of a GC column.

Analysis Shows a peak that

is proportional to the quantity of the substance present

Uses retention time instead of Rf for the qualitative analysis

https://www.youtube.com/watch?v=4Xaa9WdXVTM

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Uses of Gas Chromatography

Not considered a confirmation of a controlled substance

For more accurate results – Used in conjunction with mass spectroscopy (MS) and infrared spectroscopy (IR) a separation tool for MS and IR

Used to quantitatively measure the concentration of a sample.

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Marijuana Testing The U.S. Drug Enforcement

Administration (DEA) regulates

marijuana under the Controlled

Substances Act (CSA).

substances. Within this CSA

framework, marijuana is placed

into Schedule 1. Many testing

methods are used for detecting

THC in saliva: radio

immunoassay (RIA) method, gas

chromatography with electron

capture detection (GC-ECD),

and liquid chromatography with

electrochemical detection.

Gas chromatography-mass spectrometry (GC-MS) is the preferred method for analysis - screening and confirmation in one step.3 GC/MS is extremely selective and sensitive, enabling routine analysis of THC in saliva at the low levels required by most regulatory bodies.Testing for prosecution is actively pursued EVERYDAY.REMEMBER: Marijuana is still considered a Schedule I drug by the U.S. Government - federal laws trump state or local laws.Source: Forensic Magazine 23-29 10-17-2010

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Spectrophotometry Spectrophotometry - measures the quantity of

radiation that a particular material (i.e. drug) absorbs

Spectrophotometer—an instrument used to measure the quantity of radiation absorbed by material

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Infrared Spectrophotometry

Mass Spectrometry

Types

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Infrared (IR) Spectrometry

Material absorbs energy in the near-Infrared (IR) region of the electromagnetic spectrum.

Result—an absorption spectrum Gives a unique view of the substance; like a

fingerprint used to determine the identify of an unknown substance

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Mass Spectrometry• In the mass spectrometer, a beam

of high-energy electrons collide with a sample, producing positively charged ions.

• These positive ions almost instantaneously decompose into numerous fragments

Fragments of sample are separated according to their masses.

• The unique feature of mass spectrometry is that under carefully controlled conditions, no two substances produce the same fragment pattern.

Video

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Do Now• How does Infrared spectrophotometry

identify a specific drug?• What technique measures the amount of a

drug?

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Mass Spectrometry• Gas chromatography (GC) and mass spec have

major drawbacks, GC does not give a specific identification. Mass spectrometry cannot separate mixtures or provide specific identification.

• By combining gas chromatography and mass spectrometry, constituents of mixtures can be specifically identified.

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GC and Mass• The GC column and the mass spectrometer

can be connected to one another.

• The separation of a mixture’s components is first accomplished by the GC.

• Then, fragmentation of each separated component by high-energy electrons in the mass spectrometer, will produce a distinct pattern, or a “fingerprint” of the sample being examined.

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Collection and Preservation• The evidence must be properly packaged and

labeled for the laboratory.• The original container in which the drug was

seized will be sufficient.• All samples must be marked with information

that will ensure identification in the future and establish the chain of custody.

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ChromatographyChromatography is a means of separating and identifying the components of a mixture. • Theory of chromatography is

that chemical substances partially escape into the surrounding environment when dissolved in a liquid or when absorbed on a solid surface.

• Materials that have a preference for the moving phase will slowly pull ahead and separate from those substances that prefer to remain in the stationary phase.

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Qualitative vs. Quantitative• Analytical techniques must give either a

qualitative or a quantitative result.

Qualitative gives only the identity of the suspect material.

Quantitative gives the percent composition of the different elements in a mixture.

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ChromatographyChromatography is a means of separating and identifying the components of a mixture. • Theory of chromatography is

that chemical substances partially escape into the surrounding environment when dissolved in a liquid or when absorbed on a solid surface.

• Materials that have a preference for the moving phase will slowly pull ahead and separate from those substances that prefer to remain in the stationary phase.

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TLCSolid stationary phase (usually coated onto a glass plate) and amobile liquid phase to separate the components of the mixture. • The liquid will move up the

plate by capillary action. • The sample travels between

the stationary phase (plate) and the moving liquid phase.

• Most compounds are colorless so results must be viewed by placing the plates under UV light or spraying the plate with a chemical reagent.

• The distance a spot travels up a thin-layer plate can be measured as a numerical value or the Rf value.

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SpectrophotometrySpectrophotometry measures the quantity of radiation that a particular material absorbs as a function of wavelength and frequency.

• Beer’s Law:The quantity of light absorbed at any frequency is directly proportional to the concentration of the absorbing substance.

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UVand IR Spectrophotometry• Most forensic laboratories use

UV and IR spectrophotometers to identify chemical compounds.

• The UV spectrum is simple enough to determine the general identity of an unknown substance.

• The IR spectrum is much more exact; each IR spectrum is equivalent to a “fingerprint” of that substance.

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The Spectrophotometer• Measures the light absorption

spectrum of a chemical substance.

• The components of a spectrophotometer are:– A radiation source– A monochromator or

frequency selector– A sample holder– A detector to convert

electromagnetic radiation into an electrical signal

– A recorder to produce a record of the signal

• The light source can be the visible, ultraviolet (UV) or infrared (IR)

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GC and Mass• The GC column and the mass

spectrometer can be connected. • The separation of a mixture’s components

is first accomplished by the GC.• Then, fragmentation of each separated

component by high-energy electrons in the mass spectrometer, will produce a distinct pattern, or a “fingerprint” of the sample being examined.

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Collection and Preservation• The evidence must be properly packaged and

labeled for the laboratory.• Common sense is the best guide, the package

must prevent the loss of the sample contents and/or cross-contamination with another sample.

• The original container in which the drug was seized will be suffcient.

• All samples must be marked with information that will ensure identification in the future and establish the chain of custody.