CFI Accelerant Detection & Fire Debris Analysis 2

Question 1

In fire debris analysis, 'weathering' of an ignitable liquid refers to which process?

Accepted Answer

Preferential evaporation of lighter volatile components over time, altering the chromatographic profile

Answer

Exposure to rain and outdoor humidity during fire suppression

Answer

Absorption of atmospheric moisture into the accelerant residue

Answer

Chemical reaction between the accelerant and firefighting foam agents

Question 2

Which of the following is NOT a common source of background interference when analyzing fire debris samples for ignitable liquids?

Accepted Answer

Atmospheric nitrogen present in the sample container

Answer

Pyrolysis products from burned synthetic materials

Answer

Petroleum-based building materials such as asphalt floor tiles

Answer

Residues from firefighting foam concentrate

Question 3

What is 'matrix interference' in the context of fire debris laboratory analysis?

Accepted Answer

Chromatographic signals from burned substrate materials that can resemble ignitable liquid residues

Answer

Heat damage to evidence collection containers during the fire

Answer

Cross-contamination between different evidence samples during transport

Answer

Residue from firefighter turnout gear transferred to the debris

Question 4

What is the purpose of including a 'blank' container in a fire debris laboratory analysis submission?

Accepted Answer

To confirm that the collection containers themselves are free of contamination

Answer

To test the detection sensitivity threshold of the GC-MS instrument

Answer

To represent the expected baseline chromatogram of the burned debris

Answer

To calibrate the mass spectrometer's ionization source

Question 5

At approximately what concentration level can well-trained accelerant detection canines detect ignitable liquid residues?

Accepted Answer

Parts per trillion (ppt)

Answer

1 part per thousand (1,000 ppm)

Answer

10 parts per million (10 ppm)

Answer

1 part per billion (1 ppb)

Question 6

Which ASTM standard specifically governs the forensic analysis of fire debris samples by gas chromatography-mass spectrometry?

Accepted Answer

ASTM E1618

Answer

ASTM E1020

Answer

ASTM E1386

Answer

ASTM E2228

Question 7

In GC-MS fire debris analysis, what is the significance of identifying a 'target compound' in a sample?

Accepted Answer

It indicates the presence of a specific class of ignitable liquid within the sample

Answer

It conclusively identifies the brand and source of the accelerant used

Answer

It legally proves that arson was committed at the scene

Answer

It precisely calculates the volume of accelerant that was applied