forensics unit 11
paper chromatography: what is the mobile phase?
liquid
What organ does most of the breakdown of alcohol in the body?
liver
how does gas chromatography identify compounds
mass
why must a mixture first go through GC before the mass spectrometer
must first be separated from other substances in the mixture
morphine
narcotic
What is a positive control?
a sample prepared by the toxicologist which has a specific chemical present
A person has a blood alcohol concentration of .06%. Approximately, how long will it take the person to have 0% alcohol? Remember: .015/hour is the metabolism rate
.06 divided by .015/hour = 4 hours
if the LD50 for Lead is 20 mg/1 kg, what is the LD50 for a person weighing 70 kgs?
1400 mg
The ratio of alcohol in the blood to alcohol in alveoli air is approximately:
2,100 to 1 (The concentration in blood is MUCH more than the expelled air)
If the LD50 dose of a toxin is 15 mg/kg. What is the LD50 for a 60 kg person?
900 mg
Carbon Monoxide poisoning will cause:
Asphyxia (suffocation) from oxygen being replaced in the hemoglobin in the blood
what is the ATF
Bureau of Alcohol, Tobacco, and Firearms
How does gas chromatography work?
Chromatography separates components based on the strength of their interaction between solid material (stationary phase) and the gas that runs through the unit (the mobile phase).
What is the function of a mass spectrometer?
Determines the mass of a gaseous substance
what does the mass spectrometer do
weighs the substance
How does gas chromatography and mass spectrometry work
GC separates the components and MS will find its unique molar mass -- identifying the substance.)
Which is the standard confirmatory test for drugs and which drugs will it confirm?
GC/MS (Gas Chromatography & Mass Spectrometry) will confirm all drugs
Which technique allows for both separation and specific identification of a questioned mixture of substances?
GC/MS (Gas chromatography with mass spectrometry)
In forensic toxicology, all positive drug findings must be confirmed by a specific chemical test. The confirmation test of choice is:
Gas chromatography-mass spectrometry
A drug with the HIGHEST potential for abuse would be classified as:
I
LSD has no accepted medical use and a high potential for abuse. LSD is in which schedule?
I
How is alcohol eliminated from the body?
In urine, breath and sweat
What is a NEGATIVE control?
It is a substance, that when tested, will NOT yield a positive result.
A drug with a low potential for abuse with acceptable medical uses would most likely be put in federal schedule:
V
cocaine
amphetamines
Which toxin causes aphyxia (suffocation) from oxygen being replaced on the red blood cells?
carbon monoxide (Carbon monoxide will replace oxygen on the Red blood cells. The person will get a headache and fall asleep as he/she dies from lack of oxygen)
alcohol
depressant
barbiturates
depressant
A medication that will enhance the effect of alcohol is: (stimulant, depressant etc)
depressant (A substance in the same category as alcohol will ENHANCE (increase/worsen) the effect)
gas chromatography: what is the mobile phase?
gas
what is the state of matter when the substance goes through the mass spectrometer
gas
ecstasy
hallucinogen
marijuana
hallucinogen/ depressant
Which drugs do not require a confirmatory test:
none. all drugs require a confirmatory test
what is a negative control
nothing will happen (no reaction, no color change): a sample prepared by the toxicologist that does not have any chemicals in it.
most reliable test in a field sobriety test
nystagmus (pencil)
paper chromatography: what is the stationary phase?
paper
is gas chromatography confirmative or presumptive test
presumptive
A test, often done in the field, that involves a simple color change to detect a drug is used for:
presumptive test
A color test for drugs is often used for:
probable cause - it is presumptory test
symptoms to poisons vary according to
quantity
gas chromatography: what is the stationary phase?
solid
caffeine
stimulant
