Criminalistics Exam 4

Human performance toxicology

What type of forensic toxicology measures the amount of alcohol or drugs in a living person's blood or breath, estimates their role in modifying human performance or behavior?

postmortem analysis

What type of forensic toxicology is the presence of drugs, gases, metals, and other toxic chemicals in human fluids and organs and determines their role, if any, in the death?

human performance testing

What type of testing is most commonly performed to determine if someone is driving a car under the influence of alcohol or drugs?

What does BAC express?

Blood Alcohol Concentration

Amount of alcohol in a persons body

What is field sobriety testing?

Assesses a drivers degree of physical impairment

Alcohol is absorbed into the bloodstream largely from the ________ and the ________________

stomach; small intenstine

BAC is produced by __________

absorption

What factors influence the rate at which alcohol enters the bloodstream?

Rate of gastric emptying

Presence of food

Concentration of alcohol taken in

Type of beverage

Rate at which alcohol is consumed

What are the two mechanisms of alcohol elimination?

oxidation; excretion

How is alcohol normally excreted?

sweat

breath

urine

What is the difference between oxidation and excretion in eliminating alcohol?

In oxidation, alcohol is eventually oxidized to carbon dioxide and water

In excretion, elimination of alcohol from the body is in an unchanged state

What type of reaction is the elimination of alcohol?

Oxidation-reduction

How does the process of oxidation to eliminate alcohol work?

Alcohol is transported to the liver, where enzymes catalyze its oxidation.

First acetaldehyde then acetic acid and finally, carbon dioxide, and water

Most alcohol that enters the body is oxidized to acetic acid

What is the process for collection and preservation of blood from a living person?

Clean skin with nonalcoholic disinfectant

Add preservative (anticoagulant) to the sample

Refrigerate the sample

Why are nonalcoholic disinfectants used to clean the skin for a blood sample to obtain BAC?

Alcoholic disinfectant could make the BAC higher due to the alcohol in disinfectant

Anticoagulants keep blood from ____________

clotting

What preservative is used to inhibit microorganisms from growing and contaminating the sample?

potassium oxalate

What color capped tube are BAC blood samples collected in?

gray

How are the BAC results affected when a blood sample is not preserved correctly?

BAC results will be abnormally lower

headspace

What is the empty space above a solid or liquid in an enclosed container?

What is retention time?

the amount of time that a component stays on the column and stationary phase of a gas chromatograph

How does the headspace technique work?

Portion of headspace vapor is injected into GC/FID

Ethanol, methanol, acetone, and isopropanol identified by retention time

Concentration is calculated by calibration curve based on peak area or peak height

Gas chromatography

What technique is used to separate and detect complex mixtures of volatile organic compounds?

How does gas chromatography work?

Distributes compounds of a mixture between inert-gas

Mobile phase and a solid stationary phase

Individual components produce symmetrically shaped peaks

Area under each peak is proportional to the concentrations of that component

The concentration of ethanol and other volatiles in a dilute aqueous biological sample is directly proportional to...

their concentration in the gas phase

In what four categories are posions categorized?

inorganic

organic

biological radiological

corrosive poisons

What type of poisons are substance that destroy tissues on contact (hydrochloric acid and sulfuric acid)?

metabolic poisons

What type of poisons cause harm, and frequently death, with some essential metabolic process in the body? (cyanide and carbon monoxide)

toxic metals

What type of poisons are toxic in very small amounts (lead and mercury)?

organic poisons

What type of poisons are typically administered to incapacitate a victim (laxatives and antidepressants)?

What is pharmacology?

study of the relationship between drugs and living things

What is toxicology?

study of nature, effects, and detection of poisons

What is pharmacokinetics?

study of how drugs moce in and out of the body

What are the tasks in forensic toxicology?

Identity of drugs

Quantity of drugs

Presence of metabolites

Interactions of present drugs

Role of dependance and tolerance

metabolism

What is the process whereby a drug or other substance is chemically changed to a different form?

What are the two types of forensic toxicology?

human performance toxicology and post mortem analysis

What type of tube is used to collect blood for BAC testing?

NaF - gray capped tube

What are the main steps in the pharmacokinetics of a drug?

Absorption

Distribution

Metabolism

Elimination

What are the main steps in forensic toxicology analysis?

Extraction

Screening

Confirmation

Explain the difference between toxicology and pharmacology?

Pharmacology is the study of the relationship between drugs and living things and forensic toxicology is the study of nature, effects, and detection of poisons

Explain distribution in pharmacokinetics.

drugs may have structure to cause them to accumulate in a particular tissue

Explain metabolism in pharmacokinetics.

process whereby a drug or other substance is chemically changed to a different form

What is Rf?

distance component traveled/distance solvent traveled

mobile liquid phase

What is the term to describe capillary action that pulls solvent across plate and separates components based upon their affinity for the mobile and stationary phase?

What does ELISA stand for?

Enzyme Linked Immunosorbent Assay

The micro plates in an ELISA test are coated with _________ ________

polyclonal antibodies

Polyclonal antibodies have _____ ______ for target analytes

high affinity

In ELISA, if an analyte is present in the sample, it will form a _______ with the antibody

complex

Why are the wells washed during ELISA?

to remove unbound sample and reagent

What are the wells in ELISA washed with?

monoclonal antibodies

Monoclonal antibodies are specific to ______ analyte and another area of the _______

one; antigen

What is attached to the second antibody in ELISA?

chromogenic substrate

The intensity of ______ is proportional to the ___________ of the analyte in the sample (ELISA)

color; concentration

What is the most reliable confirmation test for BAC?

GC/MS

What does the interpretation of toxicological information in postmortem toxicology include?

How the poison entered the body

Whether enough poison was ingested to cause death

The highest concentration of poison is usually found where?

where the poison entered the body

Drugs become permanent trapped in the _______ structure of the hair

keratin

1 mL of blood will contain nearly the same amount of alcohol as _____ mL of alveolar breath

2100

What function does low BAC affect?

cerebral

What function does high BAC affect?

medullar

Describe the process of postmortem toxicology.

Case history of the deceased

Analysis for poisons

Collection of postmortem specimens

All body fluids and organs in which chemicals might accumulate

Presumptive testing performed first to detect the presence or absence of drugs

Poisons taken orally, _______ _________ should be analyzed first

gestational contents

narcotics

a substance that numbs the sense, placing the user in a stupor that eventually results in sleep

physical dependance

withdrawal sickness occurs when administration of the drug stops

psychological dependence

drug creates feelings of satisfaction and desire to repeat the experience

What factors risk dependance?

Dose

Route of administration

Frequency of administration

Metabolism

drugs with medicinal values have ______ value on the schedule

lower

Drugs with more potential for abuse have ______ schedule numbers

higher

A drug classification and control system created five schedules based on...

medicinal value

rick of harm

potential for abuse

What are the potential for abuse, medical use, and examples of Schedule I drugs?

high; noHigh potential for abuse

No currently accepted medical use

Heroin, marijuana, LSD

What are the potential for abuse, medical use, and examples of Schedule II drugs?

High potential for abuse

Currently accepted medical use

High risk for psychological or physical dependance

Opium, cocaine, PCP, most amphetamines

What are the potential for abuse, medical use, and examples of Schedule III drugs?

Less potential for abuse

Currently accepted medical use

Low to moderate risk for psychological or physical dependence

What are the potential for abuse and medical uses of Schedule IV drugs?

Low potential for abuse

Currently accepted medical use

What are examples of Schedule V drugs?

inhalers and cough medicines

What does physical dependence act on?

Central Nervous System

lock-and-key model

What is a drug molecule that fits into a receptor site in the body, initiates a particular event, and has a temporary effect?

analgesics

What type of drug lessens or eliminates pain by slowing down central nervous system?

methadone

What is a synthetic narcotic used to treat heroin addiction?

What are three examples of analgesics?

heroin

methadone

oxycontin

heroin

What analgesic has a similar physiological action to morphine because it is derived from natural morphine?

methadone

What analgesic is highly addictive, blocks euphoric rush normally produced from heroin, and reduces addicts desire to use heroin again?

oxycontin

What analgesic is a synthetic narcotic containing oxycodone that is similar to heroin and morphine?

hallucinogens

What type of drugs induce a change in mood, thought, or perception?

What are examples of hallucinogens?

marijuana, LSD, PCP, and ecstasy

What is the most commonly used illicit drug in the U.S?

marijuana

mescaline

What type of hallucinogen is found in peyote cacti and produces distortions of reality and can thrust the user into a deep meditative state?

ecstasy

What type of hallucinogen produces a heightened sense of emotion and awareness and empathy with companions and can lead to more serious effects like depression, aggression, and paranoia?

depressants

What type of drug diminishes a persons functional activity by inhibiting the activity of the nervous system?

What is the most abused drug in Western countries?

ethyl alcohol

barbiturates

What type of depressant slows down may areas of the brain?

tranquilizers

What type of depressant produces relaxed tranquility without impairing thinking or inducing sleep?

stimulants

What type of drug stimulates or speeds the central nervous system and increases alertness and physical activity?

What are examples of stimulants?

amphetamine, cocaine, inhalents

What is a clandestine lab?

hidden or secret labs that produce illicit compounds

rohypnol

Once a legal prescription in the United States, but outlawed in 2000. Date-rape drug/roofie.

ketamine

Used as a veterinary sedative or hospital-grade anesthetic

What do criminal penalties for drugs depend on?

Actual substance present in sample (qualitative)

Amount of substance present (quantitative)

Why is a screening test used in drug analysis?

Confirm samples identity

Determine mass

What are used as presumptive tests for drug analysis?

Color test reagents

Microcrystalline tests

Thin-layer chromatography

What are confirmatory tests for drugs?

IR

GC-MS