Certificate of Analysis (COA)
A document that records the tests performed and results reported for an identified sample or lot. A useful COA names the material, batch or lot, report date, methods and numerical results when applicable.
Common mistake: treating one COA as proof about every lot with the same material name. The document applies only to the sample and identifiers it lists.
Lot or batch identifier
A distinctive code used to connect material to its production, receiving and analytical records. The identifier on the report should match the container and laboratory record exactly.
Common mistake: accepting a similar-looking identifier or a report for a different lot.
HPLC and chromatogram
High-performance liquid chromatography separates detected components under a stated method. The chromatogram is the plotted detector response over time; its peaks and integration support the result reported for that method.
Common mistake: reading an HPLC area percentage as total material content. Chromatographic purity and net content are different measurements.
LC-MS and mass-to-charge ratio
Liquid chromatography-mass spectrometry combines separation with measurement of ions by mass-to-charge ratio, written m/z. Charge states and stated instrument tolerance matter when comparing an observed signal with a theoretical molecular mass.
Common mistake: assuming a mass match alone measures purity or confirms every structural detail.
Observed and theoretical mass
The theoretical mass is calculated from the intended composition. The observed mass is derived from the instrument signal. A report should make clear which values and charge states were compared.
Common mistake: comparing raw m/z directly with molecular mass without accounting for charge.
Purity and content
Purity commonly describes the relative area of a detected chromatographic peak under the stated conditions. Content addresses how much of the named material is present. Water, counter-ions and other components can make the two numbers differ.
Common mistake: treating a high purity percentage as the total amount in a container.
Acceptance criterion and numerical result
An acceptance criterion is the stated limit a result is compared with. The numerical result is the value actually reported. Recording both preserves what was measured and how it was evaluated.
Common mistake: relying on the word ‘passes’ without checking the method, limit and reported value.
Report date, supplied report and traceability
The report date records when the document was issued; sample and test dates may be different. A supplied report is reproduced as received from its issuer. Traceability is the record chain connecting the report, exact lot, receiving record and later study notes.
Common mistake: assuming publication by a seller independently verifies the report or proves a match to current inventory.
Research use only
A designation for material and documentation intended for legitimate laboratory research. It is not a direction for administration, diagnosis, treatment, or human or veterinary use.
Sources and further reading
For laboratory research documentation only. This guide is not medical advice and does not describe use in humans or animals.
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