Mass spectrometry (MS)
MSMass spectrometry is an analytical technique that identifies and quantifies molecules by ionizing them and measuring their mass-to-charge ratio.
A mass spectrometer converts sample molecules into charged ions, separates them in an electric or magnetic field according to mass and charge, and records the resulting spectrum as a fingerprint. Because the fingerprint is highly specific, the technique can confirm identity, not just the presence of something at a given retention time. It is usually paired with a separation step: gas chromatography for volatile compounds such as terpenes and residual solvents, liquid chromatography for cannabinoids and pesticides, and inductively coupled plasma for heavy metals.
Hemp testing laboratories rely on tandem mass spectrometry to reach the parts-per-billion sensitivity that pesticide and mycotoxin limits require, and the same technology underlies confirmatory drug testing of urine samples. A certificate of analysis usually lists the method used for each panel, and the abbreviations GC-MS, LC-MS/MS and ICP-MS all indicate a mass spectrometry detector.