TOXICOLOGY PART II Alcohol

Field Sobriety Tests  Officers have the right to ask individuals who are suspected of being under the influence to take field sobriety tests  National Highway Traffic and Safety Administration  3 official tests  Examine driver’s coordination, balance, and dexterity Walking in a straight line and turning around Standing on one leg while counting Horizontal gaze nystagmus

Methods of Alcohol Detection in Breath  3Types:  Breathalyzer – Colorimetry/Spectrophotometry Reduction of dichromate to chromium producing a color change from orange to green  Intoxilyzer – Infrared spectroscopy Absorption of infrared waves by alcohol  Alcosensor – Fuel cell technology Reduction of alcohol to acetic acid by a platinum catalyst. This produces a measureable electrical current.

The Breathalyzer Reaction In the field, this semi-quantitative test can be easily used. When breath containing alcohol is exhaled into the blue end of the device, it reacts with the dichromate. More green means a higher BAC.

Some Popular Breathalyzer Myths Myth: Chewing on coffee grounds, eating onions, using breath mints will help you pass a breathalyzer test Fact: Good or Bad breath does not have any impact on the test Myth: Placing pennies or batteries in your mouth before being tested Fact: No effect on the test Myth: Hyperventilating before being tested Fact: Actually increases your BAC by as much as 20%

Lit, but not the Brightest Bulb To beat a possible DUI, this man ripped apart his underwear in the back of a police car and began to eat them thinking that the cotton would absorb the alcohol. He was latter acquitted in court because his BAC was not over the legal limit. People had to be removed from the court room because they had difficulty trying to contain their laughter

Spectrophotometry  Spectrophotometry is a method used to measure the amount of a chemical substance by measuring the intensity of light that passes through a sample solution. Components of a Spectrophotometer

Color and Spectrophotometry Objects absorb only certain wavelengths of light. Those that are not absorbed are transmitted or reflected. The transmitted or reflected wavelengths are those that we see. 100% Transmittance 0% Absorbance 0% Transmittance 100% Absorbance

Creating a Standard Curve for Ethanol  Several standard solutions containing a known concentration are reacted with the dichromate reagent.  Samples are placed in the spectrophotometer and their % absorbance is measured. (one of the standards always contains 0% ethanol)  A graph is created by plotting % absorbance on the y- axis and ethanol concentration on the x-axis.

Determining the Concentration of Ethanol in an Unknown Sample  After creating a standard curve, measure the absorbance of the unknown sample and compare to the curve. An absorbance of 0.5 = 0.55% Ethanol

PA DUI Regulations  DUI - Driving Under the Influence (DWI, OUI, OMVI, DWAI, DWUI, DUIL, DUBAL)  Penalties  Jail time  License suspension  Fines  Legal Limits  21 and over – 0.08%  Under 21 – “Zero Tolerance” %  Commercial vehicle operators – 0.04% ** Over 56,000 arrests for DUI in PA last year** About 12,000 crashes and 400 fatalities