Sample Preparation
How many layers are formed in a protein precipitation extraction?
One
What is the difference between a coroner and a medical examiner?
Coroners are elected and medical examiners are forensic pathologists who have medical experience and training.
What are the two most common specimens used in human performance testing?
Blood and urine
What population is affected by performance enhancing drug testing?
Athletes
This group of elements such as nickel, chromium, iron and lead can be toxic to humans in low or high doses.
Heavy metals
What is the purpose of an internal standard?
Gives indication of the extraction quality and evaluates technique, aspects of sample preparation, and analytical instruments
What are the most common types of post-Morten toxicology specimens?
Blood, urine, vitreous humor, bile, and liver
What is the “triad” as it relates to alcohol and driving cases?
1) driving behavior
2) law enforcement investigation- signs and symptoms
3) toxicology report
What sets forensic drug testing apart from the other categories of testing?
There must be an indication of prior use
What is keratin and why is it relevant to toxicology?
Keratin is the protein in the nail which the drug is incorporated into.
Confirmatory tests should offer _____ specificity and no _____.
high; false positives
What is the role of the pathologist in death investigation?
Determine the cause and manner of death, give the family answers, review case history and information from scene, perform post-mortem examination, collect specimens, and gather data (including toxicology)
How is DRE different from Standardized Field Sobriety Testing (SFST) for alcohol?
Only 3 test for alcohol, DREs (specialized officers) can administer many more tests/exams
What is a related discipline in forensic drug testing?
Pain management
What characteristics of urine are tested to determine if the sample is “normal”?
Temperature, pH, specific gravity, creatinine, concentration, and oxidizing agents
What characteristics should be considered when selecting a solvent for an extraction?
Polarity, density, and boiling point
What is the role of the forensic toxicologist in post-mortem cases?
To determine the presence or absence of a drug and its metabolites to assist the medical examiner’s investigation.
Why are we able to determine the blood alcohol content through a breath test?
If alcohol is present, it will pass from the blood through the alveoli (gas exchange)
What are three examples of factor that affect drug and drug metabolite concentration?
dosage & frequency of use, health status, metabolic rates, routes of administration, time of sampling vs. routes of administration, and urine pH & volume
What is different about hair as a matrix that can help toxicologists determine a “history” of abuse?
Because of the months-long window of detection, long-term drug abuse and long-term alcohol abuse can be detected. Hair is not a good matrix for one time exposure.
At a pH of 4.5, would an acidic drug with a pKa of 6.5 be in the organic or aqueous layer?
Organic layer - acidic drug in neutral/un-ionized form
What are three ways or test for carbon monoxide poisoning?
Microdiffusion, GC, and spectrophotometry
What is the difference between active and inactive metabolites?
Active metabolites have therapeutic activity which may affect behavior while inactive metabolites do not have therapeutic activity and could help in determining timing of drug use.
What is the job of a medical review officer?
To evaluate and interpret results based on knowledge of substance abuse disorders and to be a liaison between labs, employers, and donors.
What is an exposome?
a measurement of the totality of exposures a person would experience from conception to death along with the associated biological response