# LC-MS

> LC-MS couples liquid chromatography with mass spectrometry, identifying compounds by mass as well as retention time; it is used for pesticides, mycotoxins and detailed cannabinoid profiling.

- Canonical: https://genetixbay.com/knowledge/glossary/lc-ms.html
- Also written: LC-MS/MS, LCMS, liquid chromatography-mass spectrometry, LC-QQQ, tandem mass spectrometry
- Glossary category: Lab testing · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

LC-MS separates compounds by [liquid chromatography](https://genetixbay.com/knowledge/glossary/hplc.md), as in HPLC, then ionises them and measures their mass-to-charge ratio. Tandem instruments (LC-MS/MS, triple quadrupole) fragment each ion and monitor specific fragments, which makes them highly selective and able to quantify trace contaminants in a complex plant matrix.

## In practice

Testing labs mainly use LC-MS/MS for [pesticide panels](https://genetixbay.com/knowledge/glossary/pesticide-panel.md) and [mycotoxins](https://genetixbay.com/knowledge/glossary/mycotoxins.md), because it reaches parts-per-billion levels and separates target compounds from cannabis's crowded background. Research groups use high-resolution LC-MS for wide [cannabinoid](https://genetixbay.com/knowledge/glossary/cannabinoid.md) profiling: Berman et al. (2018), from Dr. Dedi Meiri's lab, used ESI-LC/MS to profile scores of [phytocannabinoids](https://genetixbay.com/knowledge/glossary/phytocannabinoid.md), far beyond a routine panel. It's more expensive than HPLC-UV and needs careful calibration and matrix-matched standards.

## Don't confuse with

- **HPLC-UV**: same separation, but a UV detector; cheaper, standard for potency.
- **GC-MS**: gas-phase separation with mass detection; used for volatiles and some pesticides.
- **MS (alone)**: the detector, not the full method.

## Related terms

[HPLC](https://genetixbay.com/knowledge/glossary/hplc.md), [Pesticide panel](https://genetixbay.com/knowledge/glossary/pesticide-panel.md), [Mycotoxins](https://genetixbay.com/knowledge/glossary/mycotoxins.md), [LOD](https://genetixbay.com/knowledge/glossary/lod.md), [Gas chromatography](https://genetixbay.com/knowledge/glossary/gas-chromatography.md)

## Sources

1. Berman P, Futoran K, Lewitus GM, Mukha D, Benami M, Shlomi T, Meiri D. 2018. A new ESI-LC/MS approach for comprehensive metabolic profiling of phytocannabinoids in Cannabis. Scientific Reports 8:14280. https://doi.org/10.1038/s41598-018-32651-4