In GC-MS/MS, a sample is first vaporized before being introduced into a GC column. Within the GC column, the sample separates based on its components and  their volatilities, with more volatile compounds moving through the column faster than less volatile ones. As the separated compounds exit the column, they enter the mass spectrometer.

In the mass spectrometer, the compounds are ionized, creating charged particles. These ions are then accelerated into the analyzer, where they are sorted based on their mass to charge ratio. This highly sensitive detection technique provides detail on the structure of compounds present in the sample.

By first running a set of calibration samples of a known composition, this technique can be used to determine the composition of samples to an extremely high level of accuracy.