Lecture 8 - Explosions 8

Question 1

when was the first major attack on a soft target in the UK mainland and what did this lead to the introduction of

Answer 1

The Birmingham Pub Bombings in 1974

lead to introduction of the first Prevention of Terrorism Act

Question 2

what was the type of bombs used in The Birmingham Pub Bombings and what were they made of

Answer 2

Frangex - a type of mixed explosive typically used in mining

made of nitrocellulose dissolved in alcohol/ether mixed with nitroglycerin
KNO3 and wood pulp as the stabiliser

Question 3

what is the modern analytical technique used to detect presence of nitroglycerin

Answer 3

GC-TEA

use 3 different columns, 2 standards and compare relative retention times

Question 4

in the 70s what chemical test was used to detect nitrate ions

what was this test often paired with and why was this not the best technique

Answer 4

the Griess test
a clear colour change from colourless to pink/red - could be done at the scene

often paired with TLC = imprecise and no reliable quantitative results - trace amounts may give negative TLC results

Question 5

Dr Skuse gave evidence that lead to the conviction of the Birmingham six but what was wrong with his statements

Answer 5

he failed to consider other sources of the nitrocellulose on the mens hands r.g playing cards

Question 6

since the Birmingham bombing case what was brought into the analysis of explosive evidence to ensure this doesn’t happen (6)

Answer 6

consideration of the sensitivity and specificity of methods

clean rooms

better recovery - less contamination

multiple tests on one sample - GC-TEA uses 3 columns

don’t use chemical tests

2 separate labs do the same analysis then compare results