1. LAB SET UP INSTRUCTIONS

2. We will examine fire debris from the interior of a burned vehicle at the site of an automobile crash.

3. You will …
A) learn how forensic scientists analyze fire debris for the presence of ignitable liquid residue in suspected arson cases
B) learn to presumptively test fire debris for the presence of specific ignitable liquids by first analyzing known reference samples.

4. Application
You will then apply what you have learned in the analysis of fire debris collected from the crime scene in attempt to determine if the fire was started under suspicious circumstances.

5. 6 Groups
First, test CONTROL container. It should not be heated excessively, as heating is only necessary to volatilize the ignitable liquid present in the debris. Heating in excess may degrade the compound present.
DO NOT GO ABOVE 100 degrees C on the burner.

6. Break both ends of the tube
Colorimetric tube
Opener
(looks like washer)
With tube pointed away from body—grasp one side of washer and twist downward to break the end of the tube.

7. Place tube into jar lid
Put clay around the tube to seal it so that so fumes can not escape
Heat for minutes

8. What Happens Next? brown-green ring change on the diesel fuel tubes
As container is heated, gas will escape through tube and should generate a positive result on the tube. Work on Pre-Lab Questions during this time.
After minutes you should see a:
brown-green ring change on the diesel fuel tubes
dark green color change on the gasoline tubes.

9. The location of the ring or the front of the color change along the side of the tube is used to estimate the concentration of the ignitable liquid in the air in parts per million
ppm=mg/ L=mg/kg

10. Take your unknown evidence container and test it
Day 2--Part 2
Take your unknown evidence container and test it
Place your data onto the tables and compare with “known” test
Share your information with other teams.

11. While you await results
Take samples of
Paper
Fabric
Cardboard
Go into the greenhouse and burn a small sample. Collect the burned sample into the jar provided. Make notes regarding the physical nature of the remains.

12. Use your data information from the lab to complete the questions.
Post Lab Questions
Use your data information from the lab to complete the questions.