CHE 107 Lecture Notes - Lecture 28: Luminol, Phenolphthalein, Blood Residue

• School: Pace University
• Department: Chemistry
• Course: CHE 107
• Professor: Richardson

Document Summary

Consists of red blood cells, white blood cells, & plasma. Fundamental to crime scene investigation b/c it can provide a wealth of info about a crime. Many aspects of the crime can be determined using blood: height of blood source, how much blood was spilled, angle of impact, force at which blood was spattered. Can also aid in identification through blood typing & genetic (dna) analysis. Adult human body contains approximately 5 liters of blood: accounts for nearly 8% of person"s body weight. Presence of blood at crime scene often indicates physical struggle & provides clues about criminal event. Used in preliminary crime scene investigations due to simplicity & low cost of test. A chemical indicator, phenolphthalein, followed by a drop of hydrogen peroxide are added to unknown sample. If blood is present, iron in blood cell protein hemoglobin will oxidize phenolphthalein. Will turn into vivid pink color: luminol test: Potential bloodstain is sprayed w/ luminol reagent.