is then screened and analysed using mass
spectrometry, which involves an instrument
that breaks up ions. These ions are attracted
into a magnetic
field and when their charges are measured
in contrast to the mass of the ions, it identifies
the chemical composition of the solution.
method used is thin-layer
chromatography, which involves the liquid
sample being pushed in an upward direction by
a specially coated plate, using an organic solvent
that soaks upwards from the base. The different
components in the liquid sample move up at different
speeds and separate onto a plate, which then
allows the solution to be identified.
A mass spectrometer/gas chromatograph is situated
top left and a thin layer chromatography plate
is pictured at the bottom. Photos are both courtesy
and Borders Police Forensics Lab.