Intro to Poisons: The Poisoner’s Handbook Forensic Science 2/17/15

No Drill – Drill Quiz Take out a sheet of notebook paper and copy down these drills, question AND answer: –1/29, 2/3 When done, get a copy of “How Toxic is Toxic?” and finish working on the questions.

Objectives IWBAT –Classify and identify multiple poisons. List their effects and the tests used to detect the poison. –Define LD 50 and apply the concept to poisoning.

Pd. 5 – Drug Identification The challenge of forensic drug identification comes in selecting analytical procedures that will ensure a specific identification of a drug. This plan, or scheme of analysis, is divided into two phases. –Screening test that is preliminary to reduce the possibilities to a manageable number. –Confirmation test that is a single test that specifically identifies a substance.

Preliminary Analysis Faced with the prospect that the unknown substance may be any one of a thousand or more commonly encountered drugs, the analyst must employ screening tests to reduce these possibilities to a small and manageable number.

Confirmational Determination Once this preliminary analysis is completed, a confirmational determination is pursued. Forensic chemists will employ a specific test to identify a drug substance to the exclusion of all other known chemical substances. Typically infrared spectrophotometry or gas chromatography-mass spectrometry is used to specifically identify a drug substance.

IR Spectrum of Cocaine

IR Spectrum of Novocaine

Collection and Preservation The field investigator has the responsibility of ensuring that the evidence is properly packaged and labeled for the laboratory. Generally common sense is the best guide, keeping in mind that the package must prevent the loss of the contents and/or cross-contamination.

Often the original container in which the drug was seized will suffice. All packages must be marked with information that is sufficient to ensure identification by the officer in the future and establish the chain of custody.

How Toxic is Toxic? What is LD 50 ? Why is it a useful concept? What are the concerns with using LD 50 ? Is it always useful??

The Poisoner’s Handbook We will be watching “The Poisoner’s Handbook,” a PBS special about the rise of forensic science in New York City, focusing on the poisons that were common causes of death in the 20s and 30s. While watching the video, keep track of all of the poisons mentioned in the video, along with their effects, tests for them, and famous cases. Also, take notes on Alexander Gettler and Charles Norris—who were they? What role did their personalities and backgrounds play in their lives?

Closure List one poison discussed in today’s segment –Symptoms of poisoning –Test used by the scientists –Famous case involving this poison