Arson

Question 1

Fire

Answer 1

rapid oxidation process with the evolution of heat and light

Question 2

Explosion

Answer 2

sudden conversion of potential energy (chemical or mechanical) into kinetic energy with a production and release of gases under pressure
- has both high order and low order

Question 3

higher order explosion

Answer 3

rapid pressure rise or high force explosion characterized by shattering the confining structure or container

Question 4

low order explosion

Answer 4

a slow rate of pressurization or low-force explosion characterized by a pushing or dislodging the confining structure or container

Question 5

Fire Debris

Answer 5

certain machines used to analyze debris to identify ignitable liquid and explosive residues

Question 6

Extraction of Ignitable Liquid from fire debris

Answer 6

ignitable liquid residues (ILR) must first be isolated from the debris into a gaseous or liquid phase

Question 7

What does ILR stand for/ mean

Answer 7

ignitable liquid residues

Question 8

what are the different techniques to perform extraction of ILR

Answer 8

distillation
solvent extraction
headspace
adsorption

Question 9

Distillation

Answer 9

obsolescence

Question 10

Solvent Extraction

Answer 10

destructive

Question 11

Headspace

Answer 11

nondestructive, screening technique

Question 12

Adsorption

Answer 12

nondestructive, screening technique

Question 13

Passive headspace concentration extraction with activated charcoal

Answer 13

most commonly used technique

Question 14

Gas Chromotography- Mass Spectrometry

Answer 14

GC is the most suitable technique for separation

the detection of the analyte is achieved by utilizing Mass Spectrometry (MS)

Gas chromatography is the preferred technique for
separating the compounds in a complex mixture
based on their boiling points.

• The results are displayed as a graph showing a
  number of peaks, one scale depicts the amount of
  each component, the other the time taken for it to
  emerge from the instrument (Retention time)
• Under the same conditions, the time taken for the
  component to emerge will always be the same.

Question 15

Mass Spectrometry

Answer 15

complex chromatographic patterns can be simplified by passing the separated components through a mass spectrometer.

the mass spectrometer fragments each component into a collection of ions

each component has a unique collection of ions also referred to as its “chemical fingerprint”

Question 16

What is a chemical fingerprint? in mass spec?

Answer 16

a unique collection of ions

Question 17

analysis of extract

Answer 17

Ignitable liquids are usually composed of tens of hundreds of different compounds

analyzing the extract begins with separating its components and then detecting them

Question 18

Interpretation of results

Answer 18

most important, difficult and delicate step of fire debris analysis

consists of reviewing and analyzing the data…determine whether or not an ignitable liquid is present

characterize the liquid present in the debris…ASTM internaionl

Question 19

how does standard kerosene present?

Answer 19

eight evenly-
spaced major peaks, with a number
of minor intermediate peaks.

8 peaks are also present in a
chromatogram of diesel but in different proportions. Diesel also contains an additional eight evenly-
spaced peaks which emerge later from the instrument