chapter 7 & 8 drugs and toxicology

Chapter 7 & 8

Drugs 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

Chapter 7

Define

®Drug

®Controlled Substance

®Illicit Drug

®Prescription Drug

®Over the Counter Drug

®Poison

Kendall/Hunt Publishing Company 2

Chapter 7

Drug

®A natural or synthetic substance designed to affect humans or animals psychologically or physiologically.


Chapter 7

Controlled substance

®Identified under the Federal Schedules of the Controlled Substances Act


Chapter 7

Illicit Drug

®An illegal substance used for pleasure but not necessarily defined in the Federal Controlled Substance Act


Chapter 7

Prescription Drug

®A doctor must prescribe a drug for a specific reason.

®Misuse makes it an illicit drug.


Chapter 7

Over the Counter (OTC)

®No restrictions on purchase

®Misuse of these can and does occur

®Pseudoephedrine misuse leads to curtailed access


Chapter 7

Poison

®Almost anything can be a poison if used inappropriately

®Poison Control Center frequent calls®Children’s Tylenol®Children’s Vitamins with iron


Chapter 7 & 8

Drugs 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

Chapter 7 Kendall/Hunt Publishing Company 10

Drugs

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.

Students will learn:


Drugs

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.

Students will be able to:


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.


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.


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


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


Identification of Drugs

PDR—Physicians’ Desk Reference

Field Tests—presumptive tests

Laboratory Tests—conclusive tests


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.

Chapter 7

Product Inserts: use the guide to help you interpret your example. Answer these questions on notebook paper.

® 1. Scan your product insert® A. List the generic name and indications® B. List contraindications (and describe what that

means)® C. List warnings and adverse reactions® D. Describe dosage

® 2. Describe “black box warnings” and give 7 examples…check the handout for these.

® Does your product have a black box warning?

18


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

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 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


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.


Types of Chromatography

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


Paper Chromatography

Stationary phase—paper

Mobile phase—a liquid solvent

Capillary action moves the mobile phase through the stationary phase


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


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).


Gas ChromatographyPhases 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


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).


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.

Chapter 7

Mass Spectrometer

®A machine used to weigh molecules

®A molecular scale


Chapter 7

How is MS used?

®A mass spectrometer helps scientists®ID molecules®Determine how many molecules are

present®Determine what atoms are in a

molecule®Determine how the atoms are arranged


Chapter 7

Pocket change sorted


Chapter 7

Sorting and Counting

POCKET CHANGE

® Penny, nickel, dime, quarter, half dollar, dollar

® Sort change by value or size

® Stack them up to sort them visually

MIXTURE OF MOLECULE AND FRAGMENTS

® Mixture of different molecule fragments

® Sort fragments by mass

® Show amount of each fragment on bar graph


Chapter 7

Molecular fragments sorted


Chapter 7

HOW? Using ions

®An ion is an electrically charged atom or molecule

®Molecules must be charged to be measured by a mass spec

®A mass spec “weighs” molecules by electrically attracting and repelling ions with carefully controlled charges and force fields.


Chapter 7

Let’s get charged up!

®First, the mass spec ionizes (or charges) the molecules

®It also breaks apart the big molecule into pieces…like tearing apart a jigsaw puzzle

®This is called ionization


Chapter 7

Sort it out!

®It sorts all of these charged particles out by size


Chapter 7

®Like a pinball machine…a certain amount of force sends the ball where you want it

®A different size ball requires different force


What do the patterns tell us?MOLECULAR

FINGERPRINTS

MS Fragments...pieces of a puzzle

Scientists recognize the pieces and assemble them to identify the compound.

Each compound produces a unique spectrum.

http://www.chem.arizona.edu/massspec/example_html/examples.html

http://www.chem.arizona.edu/massspec/example_html/examples.html


Mass Spectra

Each molecular species has its own unique mass spectrum.


Spectroscopy Spectroscopy—the interaction of

electromagnetic radiation with matter. Spectrophotometer—an instrument used to

measure and record the absorption spectrum of a chemical substance.


SpectrophotometryComponents

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


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


IR Spectrophotometry andMass Spectrometry

Both work well in identifying pure substances.

Mixtures are difficult to identify in both techniques

Both are compared to a catalog of knowns


Human ComponentsUsed for Drug Analysis Blood

Urine

Hair

Gastric Contents

Bile

Liver tissue

Brain tissue

Kidney tissue

Spleen tissue

Vitreous Humor of the Eye

Chapter 7

Challenges of Tox

®Drugs must be isolated from body components, such as urine, blood, brain vitreous humor, stomach contents, liver, bile, brain


Chapter 7

Challenges of Tox

®Drugs in the body are changed chemically as the body metabolizes the drug. Scientists must understand the process and look for the metabolites.


Chapter 7

Challenges of Tox

®If the patient is alive, testing must be fast to provide medical care.

®The quantity of drug present is often important. Remember, the difference between medicine and poison is often the dose.


Chapter 7

Challenges of Tox

®The time involved is important.

®For example, in DUI cases, the body is breaking down alcohol at a predictable rate…people “sober up”

®If the blood sample is taken hours after an accident, scientists will try to calculate what the level was at the time of the accident.


Chapter 7

ID MJEasy, right?

®It’s a plant

®It’s easy to ID, but difficult for a chemist to defend in court because chemists are not botanists!


Chapter 7

The DUCK TEST

® Does it look like MJ?® Does it smell like MJ?® Pretty good chance it is MJ.

®The Duck Test

won’t fly in court!

We need science to prove it!Kendall/Hunt Publishing Company 53

Chapter 7

QUICK TESTS

®Look for cystolithic hairs

®Do a chemical test for cystolithic hairs® Add HCl® HCl reacts with

CaCO3 in hairs to form bubbles


Chapter 7

GOOD

®First another presumptive test:®Quick, easy, and sensitive®NOT specific

®Add Duquenois-Levine chemical ®MJ will turn purplish in color®The problem is, so will other things


Chapter 7

BETTER®Chromatography, a confirmatory test,

but still only screening®Components of MJ are separated using

chromatography®We see them using D-L, but this test offers

more info due to separation

®Dip strip of paper in D-L solution ®Allow colored components to separate

56


BEST: prove it with MS


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.


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.

chapter 7 & 8 drugs and toxicology

Documents

illegal drugs

prescription drugs

types of illicit drugs

controlled substanceidentified

toxicologyall substances

illicit drug types

synthetic substance

lawcontrolled substances