// Definition
A sophisticated analytical technique combining liquid chromatography with two stages of mass spectrometry. Uses a quadrupole instrument (~$185,000) to ionize and fragment compounds, then fragment the fragments, enabling identification and quantification of trace-level volatile compounds like cannabis thiols at nanogram-per-kilogram concentrations.
// From the Episode
Dr. Mark Lewis explained the technique costs ~$185K for the instrument plus $30-40K for a three-year service plan. The method requires sample derivatization and is not suitable for routine cannabis testing labs but is invaluable for research-scale breeding programs seeking to identify and select for specific aroma compounds.