Gas chromatography is another way of identifying minute quantities of substances in samples. It is used to detect banned drugs in athlete's urine samples or traces of drugs on the clothing of suspected drug traffickers. When large molecules are subjected to high temperatures they break apart into very distinct fragments. The size and nature of these fragments give the molecule or chemical a unique pattern when tested. It can be described as the chemical's own fingerprint.
Above is the chromatogram formed when drug "B" is subjected to gas chromatography. A sample of a suspect's urine was also tested and the chromatogram is shown below. It is obvious that the drug is present as all the peaks from drug "B" are present as indicated by the red arrows.
