Forensic Toxicology

Definition• The science of detecting and

identifying the presence of drugs and poisons in body fluids, tissues and organs

Controlled Substances Act

Federal Law established 5 schedules of classification of controlled substances based on: • Drug’s potential for abuse• Potential for physical and psychological dependence• Medical valueNote: Federal law also controls materials that are used in making drugs that are manufactured to resemble drugs

Drug Schedules

• Schedule I: Drugs with high potential for abuse and addiction, no medical value (i.e.: heroin, LSD, Ecstasy, Marijuana)

• Schedule II: Drugs with high potential for abuse and addiction, have some medical value with restrictions (i.e.: PCP, cocaine, amphetamines, most opiates, some barbiturates)

Drug Schedules

• Schedule III: Drugs with less potential for abuse and addiction, currently acceptable for medical use (i.e.: Some barbiturates, codeine, steroids)

• Schedule IV: Drugs with low potential for abuse and addiction, currently acceptable for medical use (i.e.: tranquilizers like valium, Xanax, Librium)

• Schedule V: Drugs with lowest potential for abuse, currently acceptable for medical use use, lowest potential dependency (i.e.: some opiates with non-narcotic ingredients)

Role of the Toxicologist

• Must identify one of thousands of drugs and poisons

• Must find nanogram to microgram quantities dissipated throughout the entire body

• Not always looking for exact chemicals , but metabolites for desired chemicals)

Toxicology Procedures

Screening: • quick test to narrow down the procedures• color tests, TLC (thin layer chromatography), GC,

immunoassayConfirmation: • Determines the exacy identity• GC?Mass Spec

Color Tests

Marquis Test• Turns purple in presence of heroin, morphine, opium • Turns orange brown in the presence of amphetaminesCobalt Thiocyanate Test (AKA Scott Test) • Three solutions• Blue then pink, then blue in the presence of cocaineDuquenois-Levine:• Test for Marijuana- turns purple

Analytical Tests

Microcrystalline Tests• Identifies drug by using chemicals that react to produce

characteristic crystals Chromatography• (TLC)Thin Layer Chromatography• (HPLC)High Performance Liquid Chromatography• Gas Chromatography

• Separate drugs for tentative identificationMass Spectrometry• Chemical fingerprint, not two drugs fragment the same way

Why?

• Think of all the people that you have heard of the “do” drugs

• US drug manufacturers produce enough barbiturates and tranquilizers each year to give each person in the US 40 pills (about 12 billion pills)

• 18,000-44,000 annual traffic deaths are alcohol related and over 2 million people sent to the hospital because of such an accident