jimtrue.com : school : CJT2141 : 10: Toxicology
Posted by Jim True on March 5, 2003 7:00 AM. Last Updated October 22, 2006 9:23 PM
Disclaimer for all material noted here is at the bottom of this web page.
Basically another form of drug analysis (still looking for controlled substances or poisons, or regular drugs), except in body fluids.
Urine, Blood, Organs, Vitreous fluid (eye fluid)
Qualitative - determining what is there
Quantitative - need to determine if overdose
Breakdown - Metabolites - drugs don't stay in there parent or regular form they change once it gets in the body.
(Heroin - Morphine [acetylization]
(Cocaine -
(Marijuana -
Acid - Base (pH Scale)
Acidic - < 7
Basic - > 7
Neutral - 7
Certain drugs prefer one pH over the other. To get to the confirmation, drugs have to be extracted from the medium they are in.
BASE - Cocaine, Opiates
ACID - Barbiturates, Tricylics
NEUT - Acetaminophen
Urine, add hydrochloric acid (wash with organic solvent), evaporate organic solvent and run GC/MS against residue for the Acid Drugs
Sodium hydroxide (basic mixture) wash with organic solvent, dry residue, run against GC/MS for Base Drugs
Quantitative: Overdose or therapeutic amount
Toxicologists - Crime Lab, ME's office, and Hospital
In auto accidents, victim gives clinical sample for treatment, but police will also want
Heavy Metals - Inorganic Analysis
Carbon Monoxide Levels (Blood)
Biological samples - refrigerated to slow down deteriation
Body decomposition can increase alcohol level (deceased sample show higher blood alcohol level)
Primary Drug looked for in Toxicology: alcohol (most abused drug in the western world)
Tools to determine presence and amount of alcohol in the blood stream
0.08% EtoH ml Blood (Alochol blood level) [Etoh - Ethyl Alcohol
Oxidation to metabolize the alcohol in the blood
Live person: urine not good for alcohol screening; Blood - Breathalyzer or Blood Draw
Pay to have the blood drawn
Primary BREATHALYZER -
Breath - easy to get, Henry's Law (Fixed Ratio between liquid and air)
Fixed Ratio Breath/Blood (2100 ml air = 1 ml blood) - Alcohol Ratio
Beer's Law - Absorption is equal to a K times Concentration
Breathalyzer - Henry's Law & Beer's law p.268 Chemical reaction being measured in the Breathalyzer
KNOW Chemical Reaction of the Breathalyzer: Potassium dichromide (color reaction with Ethyl Alcohol) + sulfuric acid (catalyst: catalytic reaction) react with ethyl alcohol to give absorption reading of the ethyl alcohol.
Breathalyzer: blow into it three times, average the three readings. minimum of 2 readings. Must be calibrated routinely.
Beat the Breathalyzer - Bianca spray or listerine, methyl alcohol, render invalid.
New Breathalyzers use IR can determine difference between methyl and ethyl alcohol.
Disclaimer: These are MY notes taken from classroom lectures while I'm in the classroom. While I'm perfectly happy to share my notes with my classmates and I know I take very good notes, you should still make every effort to attend the class and TAKE YOUR OWN NOTES. I will not transcribe everything the instructor says in the classroom, and I will NEVER post pre-exam reviews. My notes will not replace the value of actually attending class and taking your own class notes.I also cannot attest to their accuracy, other than they are what was provided in the lecture; you should not reference my notes as "expert opionion" by any means, and if you notice an error or omission, please do me the favor of e-mailing me with the correction and I will re-post my notes. End of Disclaimer.