forensic-Toxicology-Midterm

Toxicology-DEF

The study of chemicals/substances effects on living organisms

Responsibilities of a Toxicologist

• Detect if any substances/chemicals/drugs are present

• Interpret how the drugs work normally outside the scenario

• How does the drug affect the specific person

  • Each person responds different to drugs

• Establish if its a legitimate use or exposure

  • Prescription drugs or workplace exposure

(People)- Marie Larfarge

THE FIRST CRIMINAL who was charged for poisoning her husband with arsenic

Poison- DEF

Any substance/chemical/drug that taken in certain/smaller quantities, can kill or cause major damage to a human

IMPORTANT NOTE: ‘The dosage makes the poison’, meaning that the amount of poison kills you, we have small amounts right now of cyanide and mercury in us, but it doesn’t kill us.

lethality depends on two things?

• How much enters your body?

• How long it takes to enter your body?

NOTE: Anything is harmful to you if you “overdose”

You can drink too much water and breathe too much oxygen

intoxicant-DEF

Something that would need to be ingested in large amount to serve lethal (Opposite to passion)
EX: Alcohol or carbon monoxide

Collection for Drugs done by?

Collect fluids or tissues from
the body to analyze

Metabolism

The conversion of one chemical into
another by the body

The newly made product is: /// metabolites \\\

EX: When Heroin is injected, it metabolizes back into a metabolite: Morphine

Areas-Entrance site

Places where the substance can enter the body
EX: Injection sites, blood, stomach

Areas-Exit site

This is the substance,that exits our body and already metabolized.

Area-Concentration site

When drugs tend to concentrate at in mass

Entrance site- Blood

• Considered an entrance site

• toxicologist’s most useful and
  accurate substance

• Contain the traces of the drugs or metabolites

• Tells the toxicologist what occurred at the time of death

• Concentrations of substances determine levels of intoxication.

Exit site - Urine

Not as accurate as blood,

We have more influence over the concentration of the substance in our urine, given we can drink water to dilute the urine.

Entrance site -Stomach

• remove stomach contents by gastric tube

  • in the contents contain the drugs

• The contents are washed and tested

• Most useful for detecting poisons and overdoes

Concentration site-Liver

• Main organ responsible for metabolizing drugs and toxins

• Traces remain longer then blood

• Depressants, concentrate in the liver

  • opium, heroin,morphine, Oxycontin

  • Drugs that depress or suppress your body

Concentration site- Eyeballs

• Vitreous humor( The liquid inside the eyeball) can have traces of drugs

• The eyeball is very resistant to decay

  • Could be the last liquid thing in the body

• Accurate but delayed

  • Tells the story of what was in the blood only 1-2 hours before the eyeball sets in place, and begins decays

Exit site-Hair

• absorbs everything; drugs, poisons,

  environmental toxins

• Gives a good timeline

• determine whether poisoning was acute or chronic

Outside site- Insects

drugs will concentrate in the tissues of bugs
that feed on corpses.

• known as forensic entomology

Acute poison-Def

Quick intense poisoning

Chronic poison-Def

Small amounts of poison over time

Manner-Accidental

• victim unknowingly ingests a lethal
  amount of poison

• Children: usually happen at home

  • Bleach,

• adults: product is mislabeled or someone has put it in
  the wrong container.

  • Wrong prescription drugs

• Other cases are: drug dose miscalculation or dangerous mixtures of drugs

  • EX: Mixing alcohol and prescription sedatives, casues the lining in a stomach to dissolve

Manner-Succidal

• victim intentionally takes their own life

• MOST COMMON MANNER

  • For methods: Carbon Monoxide is most common method followed by prescription drug overdose.

• EX: Victim/s take multiple drugs at once.

  • makes it very hard for the ME to determine what
    actually caused the death. Multiple tests must be conducted to find exact levels and effect of the drugs

• EX: Carbon monoxide poison

Manner-Homicide

• victim is intentionally killed by someone
  else.

• LEAST COMMON MANNER

• Most commonly occurs at home.

  • victim usually knows the killer

Test- Presumptive test

• A initial screening to check if a suspected drug is present.

• Cheap and easy and less accurate

• Done mainly to give a suspicion, doesn’t 100% confirm
  EX: Breathalyzer

Test- Confirmatory test

• confirms the presence of a drug.

• Done after presumptive test

• More expensive, accurate, and time consuming

• 100% confirms presence
  EX: Blood tests

Vocab-Stimulant

• concentrates in the brain

• Increase alertness, attention, and
  energy,

• elevates blood pressure, heart
  rate, and respiration.

  • EX: cocaine, nicotine, ecstasy,

    adderall, and caffine

Vocab-Stimulant

Vocab-Tachyphylaxis

• Short: the body builds up a
  tolerance to the drug.

• Long: When taking drugs in general, our body becomes accumulated, and the high/feeling decreases. Users tend/have to take more of the substances in order to sustain that high/feeling

Vocab-Depressant

• Slows brain activity and the nervous
  system function.

• Concentrates in liver

• alcohol, opioids

  • Long term alcohol abuse is acute

  • Drinking 50 beers is chronic

• Drug Scheduling

• Schedule 1 – no medical use. Most dangerous.
  (heroin, LSD, marijuana, meth, MDMA)

• Schedule 2 – very rare for medical use, still
  very dangerous (oxycontin, cocaine, ritalin)
  • Schedule 3 – low abuse potential (codine,
  steroids)
  • Schedule 4 – very low abuse (xanax, ambien)
  • Schedule 5 – over the counter drugs

Vocab-Narcotic

• Originally referred to a variety of
  substances that dulled the senses and relieved pain.
  

• Today, it means opioid

Vocab-Benzodiazepines and Barbiturates

• Depressants that relieve anxiety, and prevent seizures (Xanax and valium

Vocab-Sedative

sleep producing substances/drug

Vocab-Analgesic

pain relieving/numbing substance/drug

Levels of drug concentration

• Normal – expected in the general population
  

• Therapeutic – level that brings about the most
  beneficial effect (appropriate use of prescription)
  

• Toxic – 1st level that causes harm: nausea, vomiting,
  or change in heart rate
  

• Lethal – level of drug that causes death

Vocab-LD50

Drug/substance blood concentration/level, at which 50% of population will perish if they ingest it

Chromatography?

• Physical separation of a mixture into its individual
  components.

• A SPIKE ON THE GRAPH, MEANS A HIGH CONCENTRATION

  • A BIG DOT ON THIN LAYER CHROMA, MEANS THE SAME

• ex: Separate the components of inks and dyes or blood and chemicals in said blood

• POSSIBLE TO BE HUNDREDS OF COMPONENTS IN ONE MIXTURE

Vocab-Chromatography-analyte

The substance that is separated during
chromatography ( statistic of blood)
EX: Cyanide,mercury,alcohol,etc separting during the process

Vocab-Chromatography-Stationary phase

when the substance/solute which is fixed in
place for the chromatography procedure

Vocab-Chromatography-solute

• The substance actually being dissolved

  • Think milk powder

• The samples we are testing

Vocab-Chromatography-Solvent

• The substance that does the disolving

  • Think water

• to any substance capable of
  dissolving other substance

Vocab-Chromatography- mobile phase

• The actual process in which the solute, and solvent are moving around

• consists of the sample being separated/analyzed and the solvent that moves the sample through the column.

Vocab-Chromatography- Retention Factor

• The measure of how far the substance it has moved up under certain conditions

  • quick way of identification

• Solvent front: The distance solvent moved up the slide

  • Usually the entire plate/slide

• Solute front: The distance solute moved up the plate

  • How far the solute moved up the slide

  • Possible there are multiple solute depending in the mixture

formula: —————>

Chromatography-Thin-Layer Chromatography

• Uses thin plastic or glass trays to identify
  the composition of a mixture

• cheaper method

• A BIG DOT ON THIN LAYER CHROMA, MEANS THE SAME

  • A SPIKE ON THE GRAPH, MEANS A HIGH CONCENTRATION

• Method: Blood (solute) is placed onto the slide that is coverd in a solvent (usually some form of gel), and overtime the solute moves up the slide

  • The lightest/lowest atomic weight will be at the top of the plate, while the heaviest closest to the blood.

Chromatography- Gas Chromatography

• Uses a specalized oven to evaporate a solute (blood), to get diffrent chemical concentrations, through the evaporated vapors

  • Blood is evaporated, and the vapor that is left over is mercury,cynaide,etc

• The vapor is caught by a carrier gas

  • A very light gas, that is used to hold onto the vapor from the solute

• THE PEAKS ON THE CHART ARE ORGANISED BY ATOMIC WEIGHT, HEAVIEST LAST, SMALLEST FIRST.

  • OPPOSITE TO THIN LAYER,

• 1st peak: The carrier gas

• 2nd Peak: Highest RF value

  • Essentially how far a compound travels

• 3rd: Highest heat vaporization

  • The heaviest atomioc weight

Vocab-Chromatography- chromatogram

results for chromatography, but not the statistics of the blood

People-Matthieu Orfila

founder of toxicology