1. Forensic Toxicology

2. Forensic Toxicology
Definition:

3. Controlled Substances Act
Federal Law established 5 schedules of classification of controlled substances based on
Drug’s potential for abuse
Potential to physical and psychological dependence
Medical Value
Also controls materials that used in making drugs and those that are manufactured to resemble drugs

4. Drug Schedules Schedule I:
Drugs with high potential for abuse and addiction, NO medical value
Ex:
Schedule II:
Drugs with high potential for abuse and addiction, have some medical value with restrictions

5. Drug Schedules Schedule III:
Drugs with less potential for abuse and addiction, currently acceptable for medical use
Ex:
Schedule IV:
Drugs with low potential for abuse and addiction, currently acceptable for medical use

6. Drug Schedules Schedule V:
Drugs with low potential abuse, medical use, lowest potential dependency
Ex:

7. Role of the Toxicologist
Must identify one of thousands of drugs and poisons
Must find milligram to gram quantities dissipated throughout the entire body
Not always looking for exact chemicals, but metabolites of desired chemicals (ex. heroin  morphine within seconds)

8. Toxicology Procedures
10mL of
Add
2 consecutive
Some drugs take a while to show up (1-3 days)

9. Toxicology Procedures
color tests, TLC, GC, immunoassay
GC-Mass Spec

10. Color Tests Marquis Test: Scott Test: Three solutions
Turns purple in the presence of Heroin, morphine, opium
Turns orange-brown in presence of Amphetamines
Scott Test: Three solutions
Blue then pink then back to blue in the presence of Cocaine
Duquenois-Levine:
Test for marijuana –turns purple

11. More Analytical Tests
Microcrystalline Tests: Identifies drug by using chemicals that reacts to produce characteristic crystals
Chromatography: TLC, HPLC and gas – separate drugs/tentative ID
Mass Spectrometry: chemical “fingerprint” no two drugs fragment the same

12. Why? Think of all the people that you have “heard” do drugs.
US drug manufacturers produce enough barbiturates and tranquilizers each year to give every person in the US 40 pills
(that’s about 12 billion pills)
18,000 out of 44,000 annual traffic deaths are alcohol related and send over 2 million people to the hospital

13. Toxicology of Alcohol
Alcohol is absorbed through the stomach and intestine
Once absorbed, alcohol is:

14. Factors that Affect Alcohol Absorption

15. Toxicology of Alcohol
Alcohol intoxication depends on

16. Toxicology of Alcohol
Alcohol 1st affects the forebrain and moves backward
Last affected is medulla oblongata

17. Analysis of BAC
Field Sobriety Tests
Breath Tests
Blood Tests

18. Field Sobriety Tests Horizontal Gaze Nystagmus Walk and Turn
Involuntary eye jerk when moving horizontally
Walk and Turn
One-Leg Stand

19. Why Breath Tests?
The ratio of alcohol in blood to alveolar air is

20. The Breathalyzer Invented in 1954 by an Indiana state trooper
Spectrophotometer designed to measure the absorption of light passing through potassium dichromate

21. The Breathalyzer
2K2Cr2O7 + 3C2H5OH + 8H2SO4  2Cr2(SO4)3 + 2K2SO4 + 3CH3COOH + 11H2O
Indirectly measures alcohol quantity by measuring amount of potassium dichromate
Potassium dichromate
Ethyl alcohol
Sulfuric acid
Chromium sulfate
Potassium sulfate
Acetic acid
Dihydrogen oxide 

22. Infrared and Fuel Cell Breath Tests
Infrared Breath Test uses infrared wavelengths to test for acetone or other interferences in the breath
Fuel Cell Test converts fuel (alcohol) and oxygen into a measurable electric current

23. Alcohol and the Law 1939-1964: intoxicated = 1965: intoxicated =

24. Alcohol and the Law
Try the drink wheel:

25. The End