sample analysis

Question 1

sample types collected

Answer 1

• fire sample - as near as possible to the seat of fire
• comparative control - same substrate but elsewhere
• negative control - tools, empty containers, work benches
• positive control - done at the end of testing

Question 2

weathering

Answer 2

samples can weather due to ageing at the scene and heating in the fire
volatiles can go missing because the evaporate away (results in misleading GC reading)