Start by checking that the document covers the batch you are asking about. Then read what was actually analysed. Purity, identity and content answer different questions and should not be treated as interchangeable measurements.
Track the batch number through the document
Compare the product name, batch number and sample identification with the supplier's information. Check who issued the report, the analysis date and whether the document has a report number. A document for the same product name but a different batch does not automatically describe the material you are assessing.
Sampling also matters. An analysis applies to the material the laboratory received. If the report does not explain how the sample was collected or linked to the production batch, this needs clarification. A laboratory's name alone does not document the sample's journey from production to analysis.
Ask for a legible report with any appendices. A screenshot of the conclusion may omit the chromatogram, method details and comments that affect how the result should be interpreted.
Distinguish identity, purity and content
HPLC can separate components in a sample. When a report expresses purity as area percentage, the calculation is tied to the signals that the method records and integrates. Water, counterions and other components are not necessarily represented by those signals. The percentage therefore cannot simply be read as the percentage of peptide in the powder's total mass.
A mass spectrum can support an identity assessment by showing masses that match expectations. How firmly identity is established depends on the analysis's resolution and any further structural investigation. An expected mass alone does not resolve every possible structural difference.
An assay or content determination must state what was quantified and how. Reference material, the basis of calculation and the unit are essential details. The fill quantity stated on the packaging and analytically determined peptide content are different types of information.
A fictional COA, for teaching only
All information in the example below was invented by ArcticAmino. EKSEMPEL-001 is not a real batch. The table and diagram are not a certificate of analysis, a laboratory report or documentation for a product we sell.
In the example, the main peak accounts for 98.4 % of the integrated HPLC signal. This figure tells us neither how many milligrams of peptide a vial contains nor whether the sample is sterile. Without a content determination and microbiological tests, those questions remain unanswered.
A result may meet the criterion for one test while the report lacks other information the research project needs. The assessment should therefore proceed test by test, with a separate list of what remains unknown.
- Identity
- Product name and which sample the laboratory analysed.
- Traceability
- Batch number, sample number and analysis date.
- Method
- The method used and what it can measure.
- Result
- Measured value, unit and any limitations.
| Field in the fictional example | Fictional information | Interpretation |
|---|---|---|
| Sample and batch | Model peptide, EKSEMPEL-001 | Fictional sample; no link to a real product |
| HPLC purity | 98.4 % area; criterion ≥ 98.0 % | Meets only the example's criterion for this test |
| Identity | Expected mass observed by LC-MS | Supports identity; the full structure is not documented here |
| Peptide content | Not analysed | Peptide quantity cannot be calculated from area purity |
| Sterility and endotoxins | Not analysed | No conclusion about these properties |
Read the criteria before the conclusion
A specification states which result is acceptable. The result is what the laboratory measured. These fields must be distinguished: text that simply repeats a limit is not necessarily a measured value. Also check whether the unit and basis of calculation are explained.
ICH Q2(R2) describes analytical method characteristics including selectivity, accuracy, precision and range. The guideline was developed for pharmaceutical analysis. It provides a scientific basis for asking whether the method suits the measurement, but does not automatically certify a research product.
Results from two laboratories may need closer comparison if the methods differ. Ask for an explanation of large discrepancies, unclear peaks or missing appendices. A polished report layout does not make these questions less relevant.
How to obtain documentation from ArcticAmino
Contact ArcticAmino to request a copy of the batch's certificate of analysis before ordering. Specify the product and the batch concerned, if the batch number is already known. Assess the documentation based on the contents of that specific report.
The article and teaching example do not replace this report. A COA also does not by itself establish lawful import, permission for a particular use or safety for human use.
Sources
ArcticAmino sells research materials. These articles are written by the supplier and summarise sources for informational purposes. They are not medical advice or instructions for use. A certificate of analysis does not make a research material an approved medicine.