forensic toxicology analytical toxicology fall 2007 analytical toxicology fall 2007

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  • Slide 1
  • Forensic Toxicology Analytical Toxicology Fall 2007 Analytical Toxicology Fall 2007
  • Slide 2
  • Forensic Toxicology Toxicology is defined as the study of the adverse effects of chemicals on living organisms. Forensic toxicology is defined as the application of toxicology for the purposes of the law.
  • Slide 3
  • Forensic Toxicology Postmortem forensic toxicology. Human performance toxicology. Forensic drug testing.
  • Slide 4
  • History Ancient Egyptians and Grecians reported poisonings due to herbs, plants and food. Opium, arsenic and hydrocyanic acid were used throughout Europe during the middle ages.
  • Slide 5
  • History Philippus Theophrastus Aureolus Bombastus von Hohenheim (or Paracelsus) observed that any substance could be a poison, depending on its dose What is there that is not poison? All things are poison and nothing without poison. Solely the dose determines that a thing is not a poison
  • Slide 6
  • History In 1814, M.J.B. Orfila, the chairman of the legal medicine department at the Sorbonne in France, published a book entitled Traite des poisons ou Toxicologie Generale.
  • Slide 7
  • History In 1851, Stas developed the first effective method for extracting alkaloids from biological specimens. This was modified several years later by Otto, which enabled the isolation of purer alkaloid substances.
  • Slide 8
  • History In the U.S., forensic toxicology did not develop until the early 20 th century. Dr. Alexander Gettler is considered this countrys first forensic toxicologist.
  • Slide 9
  • Postmortem Forensic Toxicology Suspected drug intoxication cases Homicides Arson fire deaths Motor vehicle fatalities Deaths due to natural causes
  • Slide 10
  • Postmortem Forensic Toxicology Death Investigations Coroner Medical Examiner
  • Slide 11
  • Postmortem Forensic Toxicology Specimens Blood from the heart and from the femoral or jugular veins Vitreous humor Urine Bile Liver Other lung, spleen, stomach contents or brain
  • Slide 12
  • Postmortem Forensic Toxicology Analytical Process Separation Identification Confirmation Quantitation
  • Slide 13
  • Postmortem Forensic Toxicology Analytes Volatiles (Carbon Monoxide, Cyanide, and Alcohols) Drugs Metals
  • Slide 14
  • ACETALDEHYDE (1.414 min.) EHTANOL (1.787 min.) 2-PROPANOL (2.804 min.) MEK(ISTD) (5.584 min.) ACETONE (2.462 min.) 06
  • Slide 15
  • Postmortem Forensic Toxicology Drugs One Comprehensive Approach:
  • Slide 16
  • Postmortem Forensic Toxicology Metals Aluminum Arsenic Iron Mercury Lead Thallium
  • Slide 17
  • Postmortem Forensic Toxicology Metals (continued) Analysis Colorimetric Graphite Furnace Atomic Absorption Spectrometry Inductively Coupled Plasma Mass Spectrometry Neutron Activation Spectrometry
  • Slide 18
  • Human Performance Toxicology Human performance toxicology is also referred to as behavioral toxicology. It is the study of human performance under the influence of drugs.
  • Slide 19
  • Human Performance Toxicology Ethanol and driving History Behavioral effects Specimens
  • Slide 20
  • Ethanol Toxicology Types of alcohol Ethanol (ethyl alcohol) Methanol (methyl alcohol) Isopropanol Ethylene glycol
  • Slide 21
  • Ethanol Toxicology Ethanol production Fermentation of sugar or starch Can only achieve 20% ethanol Distillation Distilled alcoholic beverages are usually 40 to 50% ethanol by volume (80-100 proof)
  • Slide 22
  • Ethanol Pharmacokinetics Absorption Means of absorption Dermal Inhalation IV Oral Gastrointestinal tract Presence of food.
  • Slide 23
  • Ethanol Pharmacokinetics Distribution Gastrointestinal tract Portal vein Liver Heart Lung Heart Body
  • Slide 24
  • Ethanol Pharmacokinetics Elimination 5-10% in the urine Saliva, expired air and sweat Liver (enzymatic oxidation to acetaldehyde, acetic acid and carbon dioxide)
  • Slide 25
  • Ethanol Effects on the Body Cardiovascular system Central nervous system Gastrointestinal tract
  • Slide 26
  • Ethanol Effects on the Body Kidney Liver
  • Slide 27
  • Breath Ethanol Testing Theory Henrys law Ethanol in breath Vs ethanol in blood 2100 to 1 ratio 2300 to 1 ratio
  • Slide 28
  • Breath Ethanol Testing Types of analyzers Chemical Reaction of ethanol with potassium dichromate/sulfuric acid solution Colored solution that results is measured spectrophotometrically IR spectrophotometry Electrochemical oxidation - fuel cell
  • Slide 29
  • Breath Ethanol Testing IR Spectrophotometry Based on absorbance of light by the ethanol molecule Mainstay in evidential breath testing devices Electrochemical Oxidation Oxidation of ethanol to acetic acid Also used in evidential breath testing
  • Slide 30
  • Blood Ethanol Testing Chemical Screening Quantitative Disadvantage - aldehydes and ketones will interfere with the test
  • Slide 31
  • Blood Ethanol Testing Enzymatic Conversion of NAD to NADH by ethanol (serum, urine and whole blood) Measured spectrophotometrically at 340 nm Same reaction with a blue dye (thiazoyl blue) (serum, urine, fresh blood and postmortem blood) Measured with a fluorometer
  • Slide 32
  • Blood Ethanol Testing Gas Chromatography Can measure ethanol in a wide range of specimens Can distinguish ethanol from other alcohols, aldehydes and ketones Two common methods Head space Direct injection ACETALDEHYDE (1.414 min.) EHTANOL (1.787 min.) 2-PROPANOL (2.804 min.) MEK(ISTD) (5.584 min.) ACETONE (2.462 min.) 06
  • Slide 33
  • Assessment of Ethanol Impairment In a British study: Detectable deterioration of drivers at between 30 50 mg/dL Obvious deterioration observed at between 60 100 mg/dL In another British study: Pilots exhibited impairment at 40 mg/dL
  • Slide 34
  • Assessment of Ethanol Impairment Blood alcohol concentration: 10-50 mg/dL: Impairment detectable by special tests 30-120 mg/dL: Beginning of sensory-motor impairment 90-250 mg/dL: Sensory-motor incoordination; impaired balance 180-400 mg/dL: Increased muscular incoordination; apathy; lethargy
  • Slide 35
  • Assessment of Ethanol Impairment Blood alcohol concentration: 250-400 mg/dL: Impaired consciousness; sleep; stupor 350-500 mg/dL: Complete unconsciousness; coma 450 and greater mg/dL: Death from respiratory arrest
  • Slide 36
  • Slide 37
  • Slide 38
  • Human Performance Toxicology Drugs and driving DEC program Drug recognition expert Toxicologist Prosecution
  • Slide 39
  • Human Performance Toxicology Drug Recognition Evaluation - 12 Step Process Breath alcohol test Interview of the arresting officer. Preliminary examination of the suspect. Examination of the eyes. Divided attention psychophysical tests. Vital signs examination.
  • Slide 40
  • Human Performance Toxicology Drug Recognition Evaluation (continued) Dark room examination. Examination of muscle tone. Examination for injection sites. Suspects statements and other observations. Opinion of the evaluator. Toxicological examination.
  • Slide 41
  • Human Performance Toxicology Drug Recognition Evaluation
  • Slide 42
  • Human Performance Toxicology Drug Recognition Evaluation
  • Slide 43
  • Human Performance Toxicology Drug Recognition Evaluation (continued) Toxicology Type of Testing Specimens
  • Slide 44
  • Human Performance Toxicology Drug Recognition Evaluation (continued) Drug Class Effects Central Nervous System Depressants Central Nervous System Stimulants Hallucinogens Phencyclidine Narcotic Analgesics Inhalants Cannabis
  • Slide 45
  • Forensic Drug Testing Introduction History Military Criminal justice system Public sector Private sector Rationale
  • Slide 46
  • Forensic Drug Testing Uses in the workplace: Pre-employment screening Post-accident testing Return to Work testing For Cause testing Random testing
  • Slide 47
  • Forensic Drug Testing Military Experience
  • Slide 48
  • Forensic Drug Testing President Ronald Reagan 1986 Executive Order No. 12564 Objective: To develop a drug-free workplace. President Ronald Reagan 1986 Executive Order No. 12564 Objective: To develop a drug-free workplace.
  • Slide 49
  • Forensic Drug Testing Mandatory Guidelines for Federal Workplace Drug Testing Programs Mandatory Guidelines for Federal Workplace Drug Testing Programs
  • Slide 50
  • Forensic Drug Testing Mandatory Guidelines Laboratory Accreditation Specified Menu & Cutoffs Proficiency Testing Inspections External Blind Controls Corrective Actions Mandatory Guidelines Laboratory Accreditation Specified Menu & Cutoffs Proficiency Testing

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