Forensic Chem - Final

Toxicology

study of poisons

Pharmocology

the study of drugs and their interactions with living systems

Forensic Toxicologist tasks

- identify drugs or poisons
- determine quantity
- understanding of metabolism and metabolites
- understanding interaction btw drugs
- grasp tolerance
- study history/patterns of drug use

3 main areas of toxicology

post mortem, human performance, urine testing

below certain dosage

no effect

therapeutic level

useful range of dosage

above therapeutic level

possible death

effective dose

the dose that gives desired effect

lethal dose

dosage that kills 50% of the population

receptor sites

core of drug action is a binding effect btw drug + receptor sites; alters existing biochemical pathways

agonists

mimic behavior of endogenous compounds; causes same effects as natural compound

antagonist

binds to site, blocks across by natural compounds like enzyme inhibitors

pharmacodynamics

the study of how drugs interact in the human body

Synergism

affect of 2+ drugs is greater than each individual drug

pharmokinetics

the study of drug and metabolite movement throughout the body

ingestion

entry of drug into body; method has impact on how + when drug appears in bloodstream

ADME

Absorption
Distribution
Metabolism
Elimination

absorption

by body into bloodstream

a drug must be ________ to be absorbed into blood

polar

drug must pass through ___ membranes

nonpolar

metabolism

to eliminate foreign substance

forensic toxicologist should know

mechanisms
metabolic structures
major/minor metabolites
kinetics

toxicity

unregulated/ unlabeled chemicals that endanger public health

behavioral toxicity

when someone is so disoriented that normal activity is dangerous

physiological toxicity

Danger to the body as a result of taking the drug

acute toxicity

adverse effects occur within a short period

chronic toxicity

adverse effects that occur after a long period

addiction

habit forming

tolerance

repeated exposure to same dose of drug

physical dependence

"needs" drug to maintain balance in body

withdrawal

body rebels when you stop

psychological/physiological

craving

metabolism 2 phase process

- change in functional group
- bind to an endogenous hydrophilic compound

elimination

any H2O soluble products eliminated in urine/ sweat

ethanol

absorbed into blood thru walls of small intestine

clearance rate

0.016% w/v per hour

questioned document

Any document where authenticity is questioned

Handwriting systems

Palmer method, zaner - bolser, D' nealian

12 common handwriting individual characteristics

- space btw letters and words
- height, size of letters
- line quality
- connecting strokes
- pen pressure
- baseline adherence
- slant
- letter formation
- embellishments
- letter characteristics

Individual variations in handwriting

We write different everytime

External Variation

Handwriting may change due to aging, injury, meds

Ideal standard

Without suspects knowledge

non-requested exemplar

already existing documents that are part of the suspect's everyday life

requested exemplar

Suspect is asked to write specific material

types of forgery

Normal hand, simulation, tracing, auto forgery

Normal hand forgery

No attempt to disguise

Simulation forgery

Copy from a model; free hand

Auto forgery

Forge own writing; intent to deny

ESDA

Electrostatic Detection Apparatus; a device that uses static electricity and toner to reveal handwriting impressions on paper

homopolymer

identical monomers

copolymer

a polymer made from two or more different monomers

thermoplastic

a material that softens when heated and hardens again when cooled

thermoset

when formed does not melt or resolidify

chain growth polymerization

'Monomer' unit becomes part of the 'polymer' chain 'one at a time'

step growth polymerization

growing chains react with each other to form even longer chains

Most common matrix

blood and plasma

redox rxn breathalyzer

ethanol is oxidized to acetic acid
potassium dichromate is reduced to chromium sulfate

Where does metabolism occur?

liver

Antemortem

whole blood - intact cells; centrifuge to separate cells from plasma

postmortem

whole blood - cells hemolyze and clot

cocaine metabolite

benzoylecgonine

methamphetamine metabolite

amphetamine

cocaine + alcohol

cocaethylene

Heroin metabolites

6 monoacetyl morphine - morphine

BAC

alcohol content / body weight x r (in grams)

r in males

0.68

r in females

0.55

BAC as a percentage

passed time x 0.016%/hr

Drug

any substance that can produce a physiological change

medicine

combination of drugs and inert ingredients

active ingredient in opium

morphine

hypodermic syringe

Media-effects theory that argues that media messages are like a drug injected directly into the audiences mind in ways that change their behavior

charles wright first synthesized

heroin

patent medicines

snake oil

opium den

Opium Exclusion Act

prohibited importation of opium

Pure Food and Drug Act

any food/drug had to be labelled; through the department of agriculture, created the FDA

harrison tax act

narcotics prescribers & manufactures must pay tax; through the department of treasury

bureau of narcotics

Henry anslinger led a media attack of weed usage

LSD

Hallucinogen; lysergic acid diethylamide

controlled substance act

established five schedules for classifying drugs; DEA was created

schedule I drugs

- High Potential for abuse
- no potential medical use
- most dangerous
- heroin, marijuana, MDMA

schedule II drugs

- High potential for abuse
- Current accepted medical use
- Abuse of drug may lead to severe psychological or physical dependence
- Morphine, cocaine, methamphetamine, PCP

schedule III drugs

- has potential for abuse, but to a lesser degree than schedules I + II
- Accepted medical use
- abuse of drug may lead to moderate or low physical dependency or high psychological dependence
- anabolic steroids, ketamine

Schedule IV drugs

- low potential for abuse
- Currently accepted medical use
- abuse may lead to limited physical or psychological dependence
- diazepam, valium, xanax

schedule V drugs

- low potential for abuse
- currently accepted medical use
- limited dependence
- cough medicine

omnibus drug act

placed chemicals into list I and II; precursor used to make drugs

Methamphetamine anti proliferation act

restrictions on the amount of pseudoephedrine that can be purchased over the counter

opiates

-naturally occurring in opium poppy
- includes morphine and codeine

Opioids

synthetic drugs derived from opiates
heroin, oxycodone

propriety

one company holds the patent

generic

after patent expires, same active ingredient as propriety

drug nomenclature

generic - active ingredient
brand - owned by 1 company

Five p's of drug evidence

powders, plants, pills, precursors, paraphernalia,

precursors

compounds that participate in a chemical rxn that produces another compound

List I precursor

VITAL in the manufacture of a controlled substance

List II precursor

USED in the manufacture of a controlled substance

cutting agents

dilute or add to effect of a drug

excipients

inactive ingredients

diluents

no pharmacological properties, fillers