Forensic Toxicology Section 1 Objectives Explain how alcohol is absorbed into the bloodstream, transported throughout the body, and finally eliminated by oxidation and excretion. Name the important parts of the human circulatory system. Describe the process by which alcohol is excreted in the breath via the alveoli. Describe the design of the Breathalyzer. Explain the significance of a chemical equation. Explain the concept of infrared and fuel-cell breath-testing devices. Demonstrate some common field sobriety tests. List common laboratory procedures for measuring alcohol’s concentration in the blood. 11/14/2018 Created by C. Ippolito Feb 2008

Role of Forensic Toxicology Uncontrolled use of drugs has increased world wide importance of the field Toxicologist detect and identify drugs and poisons in body fluids, tissues, and organs test lead exposure in children urine analysis for drug treatment programs urine analysis of prospective employees 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Toxicology of Alcohol Ethyl alcohol – most abused drug responsible for 40% of traffic deaths 17,500 fatalities per year hospitalizations from injuries 2 million per year Metabolism chemical reactions in an organism Alcohol Metabolism absorption – how it gets into systems distribution – how it moves through body elimination – how it is removed from body 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Alcohol Metabolism Absorption slowly enters bloodstream in stomach in small intestines Factors affecting adsorption: time taken to consume amount consumed alcohol content of beverage quantity and type of food in stomach 11/14/2018 Created by C. Ippolito Feb 2008

Alcohol Metabolism (con’t) Distribution equally distributed into watery parts of (2/3) body Elimination (0.015% per weight/volume per hour) Oxidation in liver (95-98%) alcohol dehydrogenase alcohol  acetaldehyde  acetic acid acetic acid  carbon dioxide and water Excretion lungs (breath) kidneys (urine) sweat glands (perspiration) 11/14/2018 Created by C. Ippolito Feb 2008

Blood Alcohol Concentration How much alcohol impairs brain function [blood alcohol] directly proportional [brain alcohol] maximum [blood alcohol] may not be reached for 2-3 hours after consumption usually 20-30 minutes after final drink absorption is completed 11/14/2018 Created by C. Ippolito Feb 2008

Alcohol Ingestion and Distribution Closed Circulatory System heart (pump) arteries - carry blood away from heart capillaries - exchange blood with tissue veins - returns blood from tissues to heart 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Alcohol Aeration Lungs alveoli oxygen and carbon dioxide exchange Henry’s Law volatile in liquid reached equilibrium with air at a fixed ratio that is constant at a given temperature at 34°C ratio is 2100 to 1 so that 1 mL of blood has the same [alcohol] as 2100 mL of breath basis of breathalyzer tests 11/14/2018 Created by C. Ippolito Feb 2008

Alcohol Recirculation and Adsorption arterial blood sends alcohol to tissues [alcohol] in arteries > [alcohol] in veins up to 41% higher 30 mins after last drink does not equalize until adsorption stage is completed 11/14/2018 Created by C. Ippolito Feb 2008

Breath Testing for Alcohol Measures [alcohol] in pulmonary artery by measuring [alcohol] in alveolar breath during absorptive phase will be higher than [alcohol] in veins Breathalyzer developed 1954 by R. Borkenstein of Indiana State Police Infrared Light Absorption Devices Fuel Cell Detectors 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Breathalyzer Test 52.5 mL collected passed through potassium dichromate reacts with alcohol forming acetic acid silver nitrate acts as catalyst 2 to 3 ratio for every 2 units of potassium dichromate used 3 units of alcohol was present 11/14/2018 Created by C. Ippolito Feb 2008

Infrared Light Adsorption Devices microprocessor controlled self calibrating breath collected IR light passed through chamber filter selects IR wavelength alcohol absorbed detector measures alcohol present 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Fuel Cell Device microprocessor controlled self calibrating platinum electrodes separated by porous acid or base containing membrane alcohol  acetic acid + free electrons current formed is proportional to alcohol in breathe 11/14/2018 Created by C. Ippolito Feb 2008

Consideration in Breath Testing need alveolar breathe (1.1 – 1.6 L) slope detector insures this avoid “mouth alcohol” regurgitation, mouth wash, etc observe 15 to 20 minutes before test take duplicate samples 11/14/2018 Created by C. Ippolito Feb 2008

Field Sobriety Testing psychophysical tests degree of impairment whether evidential test justified Alco-Sensor FST Horizontal-gaze Nystagmus involuntary jerk moving eye Walk and Turn heel to toe walk for nine steps turn and heel to toe walk back One-Leg Stand stand on one foot and count out loud 11/14/2018 Created by C. Ippolito Feb 2008

Forensic Toxicology Section 2 Objectives Describe the precautions to be taken to properly preserve blood for analysis for its alcohol content. What is the presumptive impairment level for blood alcohol in your state? Explain the significance of the implied consent law and the Schmerber v. California case to traffic enforcement. Define acid and base. Develop an appreciation for the role of the toxicologist in the criminal justice system. Describe some of the techniques that forensic toxicologists use for isolating and identifying drugs and poisons. Discuss the significance of finding a drug in human tissues and organs. 11/14/2018 Created by C. Ippolito Feb 2008

Analysis of Blood for Alcohol gas chromatography alcohol has definite peak peak size can be compared to knowns alcohol dehydrogenase NAD reaction converts NAD to NADH measurable by spectrophotometer 11/14/2018 Created by C. Ippolito Feb 2008

Collection and Preservation of Blood blood drawn by qualified person use nonalcoholic disinfectant Zepiran or Betadine sealed in airtight container anticoagulant (EDTA potassium oxalate) preservative (sodium fluoride) refrigerate postmortem bacteria produce ethanol prefer vitreous humor or urine to limit this effect 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Alcohol and the Law AMA and NSC establish uniform / reasonable blood alcohol levels Blood-Alcohol Laws AMA NSC 0.15% w/v under influence 1992 DOT recommends lower 0.08% w/v under influence 2003 states not lose fed funds Commercial Drivers 0.04% w/v under influence 11/14/2018 Created by C. Ippolito Feb 2008

Constitutional Issues Fifth Amendment protects from self-incrimination NSTA implied-consent law refusing test leads to loss of license Schmerber vs. California blood take w/o consent after accident led to conviction Supreme Court 5th Amendment prohibits testimonial self incrimination does not apply to furnishing physical evidence 4th Amendment (unreasonable search) emergency situation warranted taking taken in accepted manner without unreasonable force 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Role of Toxicologist w/o clue needs extensive “screening” using small amounts micrograms if not nanograms body actively alters substances i.e. heroin is immediately metabolized to morphine which can combine with carbs in body and not end up in urine samples 11/14/2018 Created by C. Ippolito Feb 2008

Toxicological Techniques Acid/Base control pH affects drug removal Acid – barbiturates and aspirin Basic – phencyclidine, methadone, amphetamine, cocaine Screening Tests TLC, GC, Immunoassay (monoclonal antibodies) Confirmation Tests GC followed by MS Hair Analysis used for measuring long term abuse 11/14/2018 Created by C. Ippolito Feb 2008

Created by C. Ippolito Feb 2008 Other techniques Reinsch Test screens for heavy metals treat body fluid with HCl copper strip in fluid darkens heavy metal present followed with more detailed inorganic analysis CO poisoning spectrophotometer reagent followed by GC find percent saturation 35-40 percent is fatal 8-10 percent seen in chain smokers 11/14/2018 Created by C. Ippolito Feb 2008