What it means for a research store
A mass spectrometer turns molecules into charged ions, separates them by mass-to-charge ratio and records how many ions arrive at each value. The result is a spectrum with peaks. For a material with a known structure, the laboratory compares the observed mass with the theoretical mass calculated from its formula.
Common ionisation methods include electrospray ionisation (ESI), often coupled to liquid chromatography as LC-MS, and matrix-assisted laser desorption/ionisation (MALDI), often paired with a time-of-flight analyser (MALDI-TOF). Larger molecules can carry several charges in ESI, so a spectrum may show a series of peaks that the laboratory deconvolutes into one mass.
On a COA, mass spectrometry answers the identity question: is this the expected material? It complements HPLC, which answers how pure the sample is. A report that shows only a purity figure without an identity result leaves a gap. When you publish a COA, keep the spectrum image, the observed and expected masses and the lot number together, and avoid restating the result as a broader quality claim than the report supports.
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Updated September 25, 2026. General information for merchants, not legal, tax or financial advice. This glossary does not describe the use of any compound in people.
